Rosai Chapter 12 - Mediastinum Flashcards
(263 cards)
1
Q
Most common causes of superior vena cava syndrome in adults (2)
A
- Metastatic lung carcinoma
- Malignant lymphoma
2
Q
Most common causes of superior vena cava syndrome in children (2)
A
- Malignant lymphoma
- Acute leukemia
3
Q
Usually the result of traumatic perforation of the esophagus or descent of infection from within the neck through the “danger space” anterior to the prevertebral fascia
A
-Acute mediastinitis
4
Q
Acute mediastinitis predominantly involves the:
A
Posterior mediastinum
5
Q
Typical location of chronic mediastinitis
A
Anterior mediastinum, in front of the tracheal bifurcation
6
Q
The organism most commonly identified in those cases of fibrosing mediastinitis for which a specific etiology can be determined
A
Histoplasma capsulatum (Histoplasmosis)
7
Q
Characterized by coarse, keloid-like, collagen deposition that can invade the superior vena cava, resulting in SVC syndrome, and can also invade the pulmonary hilum, resulting in complete occlusion of hilar vessels
A
Fibrosing mediastinitis
8
Q
Formed by the fusion of multiple disconnected lacunae
A
Pericardial sac
9
Q
Congenital cyst that occur along the tracheobronchial tree
A
Bronchial cyst
10
Q
Most common location of Bronchial cyst
A
Posterior to the carina
11
Q
Probably arise from a persistence, in the wall of the foregut, of vacuoles that form during the solid tube stage of development
A
Esophageal cysts
12
Q
Best evidence that a cyst in the location of the esophagus is of esophageal type
A
Presence of a definite double layer of smooth muscle in the wall
13
Q
Symptomatic congenital cysts (2)
A
- Gastric cysts
- Gastroenteric cysts
14
Q
Asymptomatic congenital cysts (3):
A
- Bronchial cysts
- Esophageal cysts
- Enteric cysts
15
Q
Largest lymph vessel in humans
A
Thoracic duct
16
Q
Most common pathologic change in mediastinal thyroid glands
A
Nodular hyperplasia
17
Q
Major cell types of the thymus (2)
A
- Epithelial cells
- Lymphocytes
18
Q
A major cell type of the thymus that is endodermally derived with a possible minor ectodermal contribution
A
Epithelial cells
19
Q
A major cell type of the thymus that is bone marrow-derived
A
Lymphocytes
20
Q
Normal location of B-cells in the thymus
A
- Thymic medulla
- Perivascular compartment
21
Q
Most salient features of Thymic dysplasia (5)
A
- very small size (less than 5 grams)
- primitive appearing epithelium without segregation into cortical and medullary regions
- presence of tubules and rosettes
- absence of Hassall corpuscles
- almost total absence of lymphocytes
22
Q
Diseases with accompanied Thymic dysplasia (3)
A
- X-linked or Autosomal recessive form of (S, A, R)
- Nezelof syndrome
- incomplete form of DiGeorge syndrome (dysplastic and located ectopically)
23
Q
X-linked or Autosomal recessive forms of these diseases has an accompanied Thymic dysplasia (3)
A
- Severe combined immunodeficiency
- Ataxia-Telangiectasia
- related chromosomal instability syndromes
24
Q
Main differential diagnosis of Thymic dysplasia
A
Acute Thymic involution
25
Best evidence against the diagnosis of primary thymic dysplasia
identification of well-formed hassall corpuscles in a thymus biopsy
26
UNILOCULAR / MULTILOCULAR
Thymic cysts:
Developmental origin arise from remnants of the 3rd branchial pouch-derived thymopharyngeal duct
Unilocular
27
UNILOCULAR / MULTILOCULAR
Thymic cysts:
usually Small
Unilocular
28
UNILOCULAR / MULTILOCULAR
Thymic cysts:
can be seen mostly in the Neck than in the mediastinum
Unilocular
29
UNILOCULAR / MULTILOCULAR
Thymic cysts:
This cervical thymic cyst is elongated and can be found anywhere along a line extending from the angle of the mandible to the manubrium sternum
Unilocular
30
UNILOCULAR / MULTILOCULAR
Thymic cysts:
Wall is thin and translucent
Unilocular
31
UNILOCULAR / MULTILOCULAR
Thymic cysts:
Lacking inflammation
Unilocular
32
UNILOCULAR / MULTILOCULAR
Thymic cysts:
Rarely has squamous lining
Unilocular
33
UNILOCULAR / MULTILOCULAR
Thymic cysts:
Thymic tissue present in the wall
Unilocular
34
UNILOCULAR / MULTILOCULAR
Thymic cysts:
Acquired process of reactive nature
Multilocular
35
UNILOCULAR / MULTILOCULAR
Thymic cysts:
Always accompanied by inflammation and fibrosis
Multilocular
36
UNILOCULAR / MULTILOCULAR
Thymic cysts:
Often has squamous lining
Multilocular
37
UNILOCULAR / MULTILOCULAR
Thymic cysts:
An acquired cystic dilation of medullary duct epithelium-derived structures, induced by an inflammatory reaction of the thymic parenchyma
Multilocular
38
Most commonly associated tumors with multilocular thymic cyst (2)
- Hodgkin lymphoma
| - Seminoma
39
Ectopic thymic tissue in the skin of the neck
Branchio-oculo-facial syndrome
40
A term that should be restricted to neoplasms of thymic epithelial cells, independently of the presence of number of lymphocytes
Thymoma
41
Usual location of thymoma
Anterosuperior mediastinum
42
A patient with myasthenia is more likely to have a thymoma if (2):
- Male; and/or
| - developing symptoms after the age of 50
43
Most accurate way to predict the likelihood of myasthenia in a patient with Thymoma
find Lymphoid follicles in the adjacent non-neoplastic thymic tissue, or, exceptionally, even in the thymoma itself
44
Features suggestive of organoid differentiation in Thymoma (5):
- perivascular spaces containing lymphocytes, proteinaceous fluid, RBCs, foamy macrophages, or fibrous tissue
- Rosettes without central lumens
- Glandlike formations within the tumor or, more often, in the tumor capsule
- True glandular structures
- Whorls suggestive of abortive Hassall corpuscle formation
45
Thymoma vs. Thymic carcinoid:
rosette-like structures with well-defined lumens
Thymic carcinoid
46
Important clue to the diagnosis of lymphocyte-rich (type B1) thymoma
find round, lighter foci of medullary differentiation
47
Most frequent aberration found in thymoma are located on:
chromosome 6 (6q25.2)
48
IHC with highest sensitivity for thymic carcinoma (2)
- MUC-1
| - GLUT-1
49
IHC showing greater specificity in separating carcinoma from thymoma
CEA
50
IHCs that stain strongly with thymic carcinoma than thymoma (3)
- p53
- BCL-2
- p16
51
Most common recurrent mutations, occurring in about 30% of cases of thymic carcinoma
TP53
52
Main differential diagnosis of Basaloid carcinoma of Thymus
Thymic carcinoma with adenoid cystic carcinoma-like features
53
Most common histologic appearance of NUT (midline) carcinoma of the Thymus
a highly undifferentiated carcinoma with variably conspicuous foci of abrupt squamous differentiation
54
Two important factors for the new nomenclature of thymic tumors:
1. Thymus is unique, can be viewed as two different organs
2. Presence, as an expression of differentiation, of a non-neoplastic lymphocytic component in the tumors composed of functional thymic tissue
55
"Thymus is unique, can be viewed as two different organs"
-The active, functional gland of the (2)
- Fetus
| - Infant
56
"Thymus is unique, can be viewed as two different organs"
-the inactive, "post mature" structure of:
-Adult life
57
Better differentiated tumors of thymus (2)
- Lymphocyte-rich
| - predominantly cortical types
58
Two major types of thymoma are based on (2):
- cytological characteristics of neoplastic epithelial cells
| - relative contribution of non-neoplastic immature T-lymphocytes typical of normal thymic cortex
59
Subdivision of type B thymomas is based on (2):
- proportional increase (in relation to the lymphocytes) of the neoplastic epithelial cells
- emergence of atypia of the neoplastic epithelial cells
60
Most reproducible features for identifying this extremely rare variant for which the term atypical type A thymoma has been proposed (2):
- Mitotic activity (more than or equal to 4/10 hpf)
| - Necrosis
61
Only feature that predicted for higher tumor stage in a large retrospective cohort of type A and AB thymomas
necrosis
62
type AB / type B1 Thymoma:
-spindled / oval morphology
type AB
63
type AB / type B1 Thymoma:
-immunoreactivity for CD20 in epithelial tumor cells within lymphocyte-rich areas
type AB
64
type AB / type B1 Thymoma:
-presence of Hassall corpuscles
type B1
65
type B1 / type B2 Thymoma:
-absence of epithelial cell clusters
type B1
66
type B1 / type B2 Thymoma:
-presence of medullary islands
type B1
67
Micronodular / type AB thymoma:
-the lymphocytes are composed mainly of B-cells and mature T-cells
Micronodular thymoma
68
Micronodular / type AB thymoma:
-Negative staining for CD20
Micronodular Thymoma
69
Most important criterion for the cytologic recognition of a thymoma
-identification of a distinct population of epithelial cells admixed with lymphocytes, preferably confirmed by a positive immunostain for keratin
70
Primary treatment of Thymoma (2)
- en-bloc surgical excision
| - complete thymectomy
71
Remains the single most important prognostic determinant, regardless of the system used, and applies equally to thymomas and thymic carcinoma
Stage
72
Directly related to the tumor stage and is also an important prognostic parameter
Completeness of excision
73
Main differential diagnosis for SETTLE
Synovial Sarcoma
74
SETTLE should be favored over Synovial sarcoma in the presence of (5):
- Stromal hyalinization
- Lower overall grade
- presence of glomeruloid glandular structures
- absence of intraglandular necrotic debris
- diffuse expression of HMW keratin
75
More significant predictors of outcome of thymic neuroendocrine tumors (3):
- Stage
- Resectability
- presence of paraneoplastic endocrinopathies
76
The presence of these features favor a diagnosis of Seminoma vs other thymic neoplasms (5):
- fibrous septa infiltrated by lymphocytes and plasma cells
- epithelioid granulomas
- numerous germinal centers
- large amounts of cytoplasmic glycogen
- an irregular, skein-like nucleolus
77
Accounts for the majority of germ cell tumors in children
Mature cystic teratoma
78
Second most common mediastinal germ cell tumor in children less than 15 years of age
Yolk sac tumor (Endodermal sinus tumor)
79
Only other type of mediastinal germ cell tumor showing trophoblastic differentiation reported in a 14-year-old boy 2 years after resection of a teratoma
Placental site trophoblastic tumor
80
Most common primary neoplasm of the middle portion of the mediastinum
Malignant Lymphoma
81
Older term for Lymphoblastic Lymphoma
Convoluted cell lymphoma
82
Other reasons for the frequent misdiagnosis of Primary mediastinal (Thymic) Large B-cell Lymphoma (5):
- perivascular collections of Lymphocytes (which may be misinterpreted as the perivascular spaces of thymoma)
- artifactual clearing of the cytoplasm induced by formalin fixation (not present in B5 or Zenker's fixed material) simulating seminoma
- presence of a large number of reactive T-cells
- rosette-like formations mimicking Thymoma and Thymic carcinoma
- Entrapment of thymic epithelium
83
A diagnosis of large cell lymphoma should be favored in the presence of (4):
- Tumor cells with large, vesicular, irregularly-shaped nuclei (indented, kidney-shaped, polylobated)
- entrapment of intrathymic and perithymic fat
- invasion of blood vessel wall, pleura, or lung
- the fact that the fibrosis is manifested not only in the form of wide hyaline bands but also as a fine network that entraps individual cells
84
an integral membrane protein located in glycolipid-enriched membrane microdomains called lipid rafts
MAL
85
A distinct molecular marker for primary mediastinal (Thymic) large B-cell lymphoma
MAL
86
Primary diseases associated with Extramedullary hematopoiesis in most patients
- Hereditary spherocytosis
| - Thalassemia
87
Two major categories of Neurogenic Tumors (2):
- tumors of the Sympathetic Nervous System
| - tumors of Peripheral Nerve Sheath
88
Anterior boundary of the mediastinum
Sternum
89
Posterior boundary of the mediastinum
Spine
90
Superior boundary of the mediastinum
Thoracic inlet
91
Inferior boundary of the mediastinum
Diaphragm
92
Most common lesions in the Superior Mediastinum (4)
- Thymoma and Thymic cyst
- Malignant Lymphoma
- Thyroid lesions
- Parathyroid adenoma
93
Most common lesions in the Middle Mediastinum (3)
- Pericardial cyst
- Bronchial cyst
- Malignant Lymphoma
94
Most common locations of Thymoma and Thymic cyst in the mediastinum (2)
- Superior
| - Anterior
95
Most common locations of Malignant Lymphoma in the mediastinum (3)
- Superior
- Anterior
- Middle
96
Most common locations of Thyroid lesions in the mediastinum (2)
- Superior
| - Anterior
97
Most common locations of Parathyroid adenoma in the mediastinum (2)
- Superior
| - Anterior
98
Most common locations of Paraganglioma in the mediastinum (2)
- Anterior
| - Posterior
99
Failure of one of the lacunar cavities to merge with the others results in the development of a:
Pericardial (coelomic) cyst
100
Usual location of Pericardial (coelomic) cyst
Right cardiophrenic angle
101
Usual lining of Bronchial cyst
Pseudostratified ciliated respiratory epithelium / ciliated columnar epithelium
102
Congenital cysts that are usually located in the posterior mediastinum in a paravertebral location, attached to the wall of the esophagus or even embedded within the muscle layer of this organ (2)
- Gastric cyst
| - Enteric cyst
103
Generic term that has been proposed for a congenital thymic alteration thought to be expression of a failure and/or arrest in the development of the organ
Thymic dysplasia
104
Main differential of thymic dysplasia that is characterized by marked lymphocytic depletion accompanied by preservation of the lobular architecture and of Hassall corpuscles
Acute Thymic Involution
105
Microscopic features of thymic involution in HIV infection (4):
- effacement of the corticomedullary junction
- marked lymphocytic depletion
- variable degrees of plasma cell infiltration and fibrosis
- inconspicuous Hassall corpuscles
106
defined as thymic enlargement beyond
the upper limits of normal for the age (as determined by weight using the Hammar table or by volumetric measurement) but accompanied by a microscopically normal gland
True thymic hyperplasia
107
defined as the presence of more than an occasional lymphoid follicle in the thymus independent of the size of the gland.
Thymic follicular hyperplasia
108
Tumors of the Anterior Mediastinum:
Patterns (LPO) - Sharply defined, angular lobules
Thymoma
109
Tumors of the Anterior Mediastinum:
Patterns (LPO) - Fibrous bands and capsule
Thymoma
110
Tumors of the Anterior Mediastinum:
Patterns (LPO) - Mottling and trabeculation (caused by epithelial– lymphocyte admixture)
Thymoma
111
Tumors of the Anterior Mediastinum:
Nuclei - Often fine chromatin contrasting with well-defined nuclear membrane
Thymoma
112
Tumors of the Anterior Mediastinum:
Nuclei - Usually inconspicuous nucleoli; great variation, including spindle shape
Thymoma
113
Tumors of the Anterior Mediastinum:
Nuclei - Epithelial mitoses usually rare
Thymoma
114
Tumors of the Anterior Mediastinum:
Cytoplasm - Great variation from scant to squamoid to squamous
Thymoma
115
Tumors of the Anterior Mediastinum:
| Cytoplasm - Intracytoplasmic cysts
emperipolesis
Thymoma
116
Tumors of the Anterior Mediastinum:
Cytoplasm - Glandlike spaces
Thymoma
117
Tumors of the Anterior Mediastinum:
Associated features - Germinal centers in surrounding thymus (in cases of myasthenia gravis)
Thymoma
118
Tumors of the Anterior Mediastinum:
Associated features - Incorporation of non-neoplastic thymus (13%)
Thymoma
119
Tumors of the Anterior Mediastinum:
Electron microscopy - Well-formed desmosomes
Thymoma
120
Tumors of the Anterior Mediastinum:
IHC - Keratin
Thymoma
121
Tumors of the Anterior Mediastinum:
Patterns (LPO) - Diffuse growth
Large cell lymphoma
122
Tumors of the Anterior Mediastinum:
Patterns (LPO) - Variable fibrosis with
occasional compartmentalizing sclerotic pattern
Large cell lymphoma
123
Tumors of the Anterior Mediastinum:
Patterns (LPO) - Residual cystic thymus
Large cell lymphoma
124
Tumors of the Anterior Mediastinum:
Nuclei - Vesicular with prominent nucleoli
Large cell lymphoma
125
Tumors of the Anterior Mediastinum:
| Nuclei - Marked folding of nuclei
“cloverleaf”
Large cell lymphoma
126
Tumors of the Anterior Mediastinum:
Nuclei - Variable chromatin pattern
Large cell lymphoma
127
Tumors of the Anterior Mediastinum:
Nuclei - Mitotic figures variable (usually readily found)
Large cell lymphoma
128
Tumors of the Anterior Mediastinum:
Cytoplasm - Variable, occasionally abundant and rich in RNA (methyl green–pyronine positive)
Large cell lymphoma
129
Tumors of the Anterior Mediastinum:
Associated features - Residual lymphocytes often form tight perivascular cuffs
Large cell lymphoma
130
Tumors of the Anterior Mediastinum:
Associated features - Necrosis frequent
Large cell lymphoma
131
Tumors of the Anterior Mediastinum:
Associated features - Markedly invasive
Large cell lymphoma
132
Tumors of the Anterior Mediastinum (2):
Electron microscopy - Nuclear blebs
- Large cell lymphoma
| - Lymphoblastic lymphoma
133
Tumors of the Anterior Mediastinum (2):
Electron microscopy - Absence of epithelial features
- Large cell lymphoma
| - Lymphoblastic lymphoma
134
Tumors of the Anterior Mediastinum:
IHC - B-lymphocyte markers
Large cell lymphoma
135
Tumors of the Anterior Mediastinum:
Patterns (LPO) - Diffuse growth or pseudonodular pattern (both in lymph nodes and in thymus)
Lymphoblastic lymphoma
136
Tumors of the Anterior Mediastinum:
Nuclei - Even chromatin (“dusky” at low power)
Lymphoblastic lymphoma
137
Tumors of the Anterior Mediastinum:
Nuclei - Scant inconspicuous nucleoli
Lymphoblastic lymphoma
138
Tumors of the Anterior Mediastinum:
Nuclei - Numerous mitotic figures
Lymphoblastic lymphoma
139
Tumors of the Anterior Mediastinum:
Cytoplasm - Scant
Lymphoblastic lymphoma
140
Tumors of the Anterior Mediastinum:
Associated features - Residual Hassall corpuscles
Lymphoblastic lymphoma
141
Tumors of the Anterior Mediastinum:
Electron microscopy - Fine chromatin
Lymphoblastic lymphoma
142
Tumors of the Anterior Mediastinum:
IHC - T-lymphocyte markers
Lymphoblastic lymphoma
143
Tumors of the Anterior Mediastinum:
Patterns (LPO) - Extensive fibrosis with rounded lobules of tumor
Thymic Hodgkin Lymphoma
144
Tumors of the Anterior Mediastinum:
Patterns (LPO) - Prominent cysts seen at low power
Thymic Hodgkin Lymphoma
145
Tumors of the Anterior Mediastinum:
Nuclei - Cytologic features— those of nodular sclerosing Hodgkin lymphoma complicated by admixture with thymic epithelium and cysts
Thymic Hodgkin Lymphoma
146
Tumors of the Anterior Mediastinum:
Cytoplasm - Lacunar cells often prominent
Thymic Hodgkin Lymphoma
147
Tumors of the Anterior Mediastinum:
Electron microscopy - Absence of epithelial
characteristics in Reed– Sternberg cells
Thymic Hodgkin Lymphoma
148
Tumors of the Anterior Mediastinum:
IHC - CD15, CD30
Thymic Hodgkin Lymphoma
149
Tumors of the Anterior Mediastinum:
Patterns (LPO) - Subdivided by fine fibrous trabeculae into variable-sized compartments
Thymic Seminoma
150
Tumors of the Anterior Mediastinum:
Nuclei - Coarse chromatin, marked prominence of nucleoli, variable numbers of mitotic figures
Thymic Seminoma
151
Tumors of the Anterior Mediastinum:
Cytoplasm - Marked retraction of cytoplasm; often glycogen rich
Thymic Seminoma
152
Tumors of the Anterior Mediastinum:
Associated features - Germinal centers, epithelioid and giant cells
Thymic Seminoma
153
Tumors of the Anterior Mediastinum:
Electron microscopy - Even chromatin
Thymic Seminoma
154
Tumors of the Anterior Mediastinum:
Electron microscopy - Prominent nucleoli
Thymic Seminoma
155
Tumors of the Anterior Mediastinum:
Electron microscopy - Glycogen rich
Thymic Seminoma
156
Tumors of the Anterior Mediastinum:
Electron microscopy - Scant desmosomes
Thymic Seminoma
157
Tumors of the Anterior Mediastinum:
Electron microscopy - Only rare tonofilaments
Thymic Seminoma
158
Tumors of the Anterior Mediastinum:
IHC - PLAP, CD117
Thymic Seminoma
159
Tumors of the Anterior Mediastinum:
Patterns (LPO) - Ribbons, festoons, punctate calcified necrosis producing discrete and rounded masses of tumor
Thymic Carcinoid
160
Tumors of the Anterior Mediastinum:
Nuclei - Variable number of mitotic figures (note spindle cell variant)
Thymic Carcinoid
161
Tumors of the Anterior Mediastinum:
Nuclei - Rounded nuclei with sharp stippling chromatin
Thymic Carcinoid
162
Tumors of the Anterior Mediastinum:
Cytoplasm - Polyhedral cells with finely granular eosinophilic cytoplasm
Thymic Carcinoid
163
Tumors of the Anterior Mediastinum:
Cytoplasm - True gland formation
Thymic Carcinoid
164
Tumors of the Anterior Mediastinum:
Electron microscopy - Dense-core granules
Thymic Carcinoid
165
Tumors of the Anterior Mediastinum:
Electron microscopy - Desmosomes inconspicuous or poorly formed
Thymic Carcinoid
166
Tumors of the Anterior Mediastinum:
Electron microscopy - Tonofilaments only rarely prominent
Thymic Carcinoid
167
Tumors of the Anterior Mediastinum:
IHC - Chromogranin, Synaptophysin
Thymic Carcinoid
168
This IHC stain is usually restricted either to the glandlike formations of spindle thymomas or to the tumors predominantly composed of round or polygonal cells
EMA
169
Interdigitating cells located in the medullary portion of the more organoid thymomas
Asteroid cells
170
Defined as a thymic epithelial tumor exhibiting clear-cut cytologic features of malignancy
Thymic carcinoma
171
a receptor molecule that signals cell growth in T cells
CD5
172
IHC stain which is present in the majority of thymic carcinomas but absent in other types of thymoma and in carcinomas of nonthymic origin
CD5
173
IHC stain that is positive in 80% or more of thymic carcinomas, almost always negative in thymomas, and occasionally positive in nonthymic carcinomas
CD117 (c-kit)
174
a member of the tumor necrosis (TNF) family that mediates the interaction between B and T lymphocytes which is present in most thymic carcinomas but not in conventional thymomas
CD70
175
this form of thymic carcinoma is composed
of atypical polygonal epithelial cells arranged in characteristic epidermoid growth patterns often with associated intercellular bridges
Squamous cell carcinoma
176
This tumor is formed by well-defined epithelial islands with prominent
peripheral palisading, a combination of features typical of basaloid carcinomas arising in other sites including the lung.
Basaloid carcinoma
177
Areas of squamous and mucin-producing glandular differentiation alternate in this neoplasm
Mucoepidermoid carcinoma
178
large, deeply acidophilic nucleoli that are sharply outlined and perfectly round are one of the hallmarks of this neoplasm, which is also characterized by a “syncytial” appearance
Lymphoepithelioma-like carcinoma
179
PRESENT / ABSENT:
Keratinization in Lymphoepithelioma-like carcinoma
Absent
180
PRESENT / ABSENT:
Intercellular bridges in Lymphoepithelioma-like carcinoma
Absent
181
Positive IHCs in Lymphoepithelioma-like carcinoma (3):
- Keratins, including HMW CK such as CK5/6
- p63
- p40
182
This cytologically malignant tumor simulates a mesenchymal neoplasm by virtue of its diffuse pattern of growth and the prominent spindling of tumor cells
Sarcomatoid carcinoma (Carcinosarcoma)
183
Previous names of Metaplastic thymoma (2)
- Thymoma with pseudosarcomatous stroma
| - Low-grade metaplastic thymic carcinoma
184
It is characterized by a biphasic epithelial and spindle cell morphology, with absence of significant atypia and low proliferation rates in both components
Metaplastic thymoma
185
a form of high-grade carcinoma frequently demonstrating squamous differentiation that tends to affect midline structures, most commonly the mediastinum
NUT (midline) carcinoma
186
This tumor shows no detectable differentiation in any specific direction
and tends to exhibit considerable pleomorphism.
Undifferentiated (Anaplastic) Carcinoma
187
Type A / Type B thymomas:
Thymomas in which neoplastic epithelial cells and their nuclei have a spindle/ oval shape with few, if any, non-neoplastic T cells.
Type A thymomas
188
Type A / Type B thymomas:
Thymomas in which neoplastic epithelial cells have a dendritic or plump (“epithelioid”) appearance and a variably conspicuous component of non-neoplastic immature T cells.
Type B thymomas
189
Other name of Type A thymoma (2):
- Spindle cell
| - Medullary
190
A tumor composed of a population of neoplastic thymic epithelial cells having a spindle/oval shape, lacking nuclear atypia, and accompanied by few or no non-neoplastic lymphocytes
Type A thymoma
191
other name of Type AB thymoma
Mixed
192
A tumor in which foci having the features of type A thymoma are admixed with foci rich in lymphocytes including a significant proportion of immature T cells
Type AB thymoma
193
other name of Type B1 thymoma (4):
- Lymphocyte-rich
- Lymphocytic
- Predominantly Cortical
- Organoid
194
A tumor that resembles the normal functional thymus in that it combines large expanses having an appearance practically indistinguishable from normal thymic cortex in which cytologically bland thymic epithelial cells are evenly dispersed within a background of immature T cells and accompanied by areas resembling thymic medulla
Type B1 thymoma
195
other name of Type B2 thymoma
Cortical
196
A tumor in which the neoplastic epithelial component appears as scattered plump cell, often including small (≥3 contiguous epithelial cells) clusters, with vesicular nuclei and distinct nucleoli among a heavy population of immature T cells.
Type B2 thymoma
197
Type of thymoma in which perivascular spaces are common and sometimes very prominent
Type B2 thymoma
198
Type of thymoma in which a perivascular arrangement of tumor cells resulting in a palisading effect may be seen
Type B2 thymoma
199
other name of Type B3 thymoma (4):
- Epithelial
- Atypical
- Squamoid
- Well-differentiated thymic carcinoma
200
A type of thymoma predominantly composed of mildly atypical epithelial cells having a round or polygonal shape admixed with a minor component of immature T cells, resulting in a sheetlike growth of the neoplastic epithelial cells
Type B3 thymoma
201
characterized by a micronodular growth pattern in which epithelial islands are separated by lymphoid stroma that may include florid follicular hyperplasia
Micronodular thymoma
202
another rare subtype that is a biphasic tumor
in which solid areas of epithelial cells are variably well demarcated from cytologically bland, fibroblast-like spindle cells
Metaplastic thymoma
203
refers to thymomas measuring less than 0.1 cm in greatest dimension and are usually discovered as multifocal incidental findings in thymectomies from patients with myasthenia gravis
Microscopic thymoma
204
Other name of Microscopic thymoma
Nodular hyperplasia
205
A thymic tumor exhibiting clear-cut cytologic atypia and a set of cytoarchitectural features no longer specific to the thymus (as for types A, AB, and B thymomas) but rather analogous to those seen in carcinomas of other organs
Thymic carcinoma
206
Modified Masaoka-Koga stage:
Grossly and microscopically encapsulated tumor
Stage I
207
Modified Masaoka-Koga stage:
Capsular invasion
Stage II
208
Modified Masaoka-Koga stage:
Limited (≤3 mm) microscopic transcapsular invasion
Stage IIa
209
Modified Masaoka-Koga stage:
Macroscopic (microscopically confirmed) invasion into thymic or surrounding adipose tissue without pleural or pericardial involvement
Stage IIb
210
Modified Masaoka-Koga stage:
- Macroscopic (microscopically confirmed) invasion into neighboring organs (i.e. mediastinal pleura, pericardium, visceral pleura ± lung parenchyma, phrenic or vagus nerves, major vessels)
- adherence (i.e. fibrous attachment) to lung or other adjacent organs if (and only if) there is concomitant microscopic invasion of mediastinal pleura and/or pericardium
Stage III
211
Modified Masaoka-Koga stage:
Metastases
Stage IV
212
Modified Masaoka-Koga stage:
Pleural or pericardial metastases (i.e. nodules separate from main mass involving visceral or parietal pleura, or pericardial or epicardial surfaces)
Stage IVa
213
Modified Masaoka-Koga stage:
Lymphogenous (intrathoracic or extrathoracic lymph nodes) or hematogenous (pulmonary parenchymal or extrathoracic) metastases
Stage IVb
214
AJCC
Primary tumor (pT):
Primary tumor cannot be assessed
TX
215
AJCC
Primary tumor (pT):
No evidence of primary tumor
T0
216
AJCC
Primary tumor (pT):
-Tumor encapsulated or extending into the mediastinal fat
-may involve the mediastinal
pleura
T1
217
AJCC
Primary tumor (pT):
Tumor with no mediastinal pleura involvement
T1a
218
AJCC
Primary tumor (pT):
Tumor with direct invasion of mediastinal pleura
T1b
219
AJCC
Primary tumor (pT):
Tumor with direct invasion of the pericardium (either partial or full thickness)
T2
220
AJCC
Primary tumor (pT):
Tumor with direct invasion into any of the following:
- lung,
- brachiocephalic vein,
- superior vena cava,
- phrenic nerve,
- chest wall, or
- extrapericardial pulmonary artery or veins
T3
221
AJCC
Primary tumor (pT):
Tumor with invasion into any of the following:
- aorta (ascending, arch, or descending),
- arch vessels,
- intrapericardial pulmonary artery,
- myocardium,
- trachea,
- esophagus
T4
222
AJCC
Regional Lymph Node (N):
Regional lymph nodes cannot be assessed
NX
223
AJCC
Regional Lymph Node (N):
No regional lymph node metastasis
N0
224
AJCC
Regional Lymph Node (N):
Metastasis in anterior (perithymic) lymph nodes
N1
225
AJCC
Regional Lymph Node (N):
Metastasis in deep intrathoracic or cervical lymph nodes
N2
226
AJCC
Distant Metastasis (M):
No pleural, pericardial, or distant metastasis
M0
227
AJCC
Distant Metastasis (M):
Pleural, pericardial, or distant metastasis
M1
228
AJCC
Distant Metastasis (M):
Separate pleural or pericardial nodule(s)
M1a
229
AJCC
Distant Metastasis (M):
Pulmonary intraparenchymal nodule or distant organ metastasis
M1b
230
AJCC
T1, Level 1 structures (3):
- Thymus
- Anterior mediastinal fat
- Mediastinal pleura
231
AJCC
T2, level 2 structure:
-Pericardium
232
AJCC
T3, level 3 structures (6):
- Lung
- Brachiocephalic vein
- Superior vena cava
- Phrenic nerve
- Chest wall
- Hilar pulmonary vessels
233
AJCC
T4, level 4 structures (6):
- Aorta (Ascending, Arch, or Descending)
- Arch vessels
- Intrapericardial pulmonary artery
- Myocardium
- Trachea
- Esophagus
234
Microscopic subtype of thymoma and the likelihood of invasion:
B3>B2>B1>AB>A
235
Tumors in the neck:
Gender - M>F
Ectopic hamartomatous thymoma
236
Tumors in the neck (2):
Gender - Females more than males
- Ectopic cervical thymoma
| - CASTLE
237
Tumors in the neck:
Gender - M=F (about the same)
SETTLE
238
Tumors in the neck:
Mean age - 49.9
Ectopic hamartomatous thymoma
239
Tumors in the neck:
Mean age - 42.7
Ectopic cervical thymoma
240
Tumors in the neck:
Mean age - 15
SETTLE
241
Tumors in the neck:
Mean age - 48.5
CASTLE
242
Tumors in the neck:
Anatomic location - Supraclavicular or suprasternal soft tissue
Ectopic hamartomatous thymoma
243
Tumors in the neck:
Major Histologic Features:
- Circumscribed
- haphazard admixture of bland-looking spindle (epithelial) cells, solid and cystic epithelial islands (commonly squamous and glandular), and mature fat cells
Ectopic hamartomatous thymoma
244
Tumors in the neck:
Behavior:
- Benign
- No recurrence or metastasis after excision
Ectopic hamartomatous thymoma
245
Tumors in the neck:
Anatomic location - Soft tissue of neck, often in a juxtathyroid location, or sometimes inside thyroid
Ectopic cervical thymoma
246
Tumors in the neck:
Major Histologic Features:
- Similar to mediastinal thymomas
- encapsulated or invasive
- jig-saw puzzle-like lobules
- mixture of pale epithelial cells (plump or spindled) and lymphocytes
Ectopic cervical thymoma
247
Tumors in the neck:
Behavior:
-Most pursue a benign course with no recurrence; exceptionally, metastasis can occur
Ectopic cervical thymoma
248
Tumors in the neck:
Anatomic location - Thyroid gland
SETTLE
249
Tumors in the neck:
Major Histologic Features:
- Encapsulated or infiltrative
- highly cellular tumor
- merging of compact or reticulated spindle (epithelial) cells with glandular elements
- mucous glands often present
- component of lymphocytes lacking
SETTLE
250
Tumors in the neck:
Behavior:
Protracted clinical course, with a propensity to develop delayed distant metastasis
SETTLE
251
Tumors in the neck:
Anatomic location - Thyroid gland (usually lower pole) and surrounding soft tissue, or soft tissues of the neck
CASTLE
252
Tumors in the neck:
Major Histologic Features:
- Lymphoepithelioma-like carcinoma that may show foci of squamous differentiation
- lobulation
- pushing margins
- lymphocytic infiltration often present
CASTLE
253
Tumors in the neck:
Behavior:
- Generally indolent tumor that can recur after long intervals
- regional lymph node metastasis occurs in about half of the cases
- occasional cases pursue a more aggressive course
CASTLE
254
The microscopic appearance of
| this tumor is not noticeably different from that of its orthotopic mediastinal counterpart
Ectopic (cervical) thymoma
255
an encapsulated benign thymic lesion that can attain a huge size and can simulate radiographically cardiomegaly or pulmonary sequestration.
Thymolipoma
256
IHC stains helpful in distinguishing Mediastinal Seminoma (Germinoma) vs Thymic carcinoma
Postivity of Mediastinal Seminoma with:
- OCT3/4
- SALL4
257
defined, as in other sites, as a germ cell
tumor similar to mature teratoma but also containing immature epithelial, mesenchymal, or neural elements without a component of embryonal carcinoma
Immature teratoma
258
an invasive, highly necrotic neoplasm and its microscopic appearance is, by definition, poorly differentiated.
Embryonal carcinoma
259
IHCs for Embryonal carcinoma (6):
- Keratin
- PLAP
- OCT4
- SALL4
- CD30
- CD57 (Leu7)
260
IHC stains to distinguish Yolk sac tumor (endodermal sinus tumor) (2)
- OCT4-
| - SALL4+
261
an older term used to describe mixed germ cell tumors characterized by a combination of embryonal carcinoma and teratoma (mature and/or immature), and comprises about 5% of all mediastinal germ cell tumors.
Teratocarcinoma
262
Subtype of Hodgkin Lymphoma nearly always present in mediastinum
Nodular sclerosis
263
A diffuse accumulation of mature adipose tissue that may occur in association with obesity, Cushing disease, or steroid therapy, and which can lead to a "sabre sheath" tracheal deformity radiographically
Lipomatosis
