Lung Cancer - Pathology

Question 0

3 main types of primary lung epithelial cancers?

Answer 0

Non-Small Cell Lung Cancer (NSCLC)- 80%.
Small Cell - 15-20%.
Carcinoid. - 1-2%.
(and salivary gland-like… but don’t worry about that)

Question 1

Broadly speaking, what kind of tumors are most commonly found in the lungs?

Answer 1

Metastases from other organs.

Question 2

3 types of NSCLC?

Answer 2

Adenocarcinoma. (most common)
Squamous cell.
Large cell.

Question 3

Typical demographic for patients with adenocarcinoma?

Answer 3

Women, non-smokers.

Question 4

Adenocarcinoma of the lung histologic appearance?

Answer 4

Lots of gland, with or without mucus.

just like other adenocarcinomas we’ve seen

Question 5

3 major grades of adenocarcinoma of the lung?

Answer 5

Non-invasive - Atypical adenomatous hyperplasia (AAH), adenocarcinoma in situ (AAS).
Minimally invasive.
Invasive.

Question 6

How are minimally invasive and invasive adenocarcinoma of the lung distinguished?

Answer 6

Depth of invasion: < 0.5 cm is minimally invasive.

Question 7

Features of adenocarcinoma in situ (AIS)?

Answer 7

No invasion.
Lepidic growth - i.e. along alveolar surface.
Can be mucinous or non-mucinous.
(this was formerly called Bronchioloalveolar Carcinoma -BAC)

Question 8

2 histologic patterns of a invasive adenocarcinoma?

Answer 8

Papillary (fibrovascular cores).
Acinar.
…but it can be mixed.

Question 9

What’s a notable histologic feature of AIS, other than a lepidic growth pattern?

Answer 9

Cuboidal or columnar “hobnail” cells with atypical nuclei.

Question 10

Mucinous AIS is rare, but what does it look like on histology?

Answer 10

Lots of mucinous, goblet-like cells. Lots of mucin.

Question 11

3 histologic patterns of invasive adenocarcinoma?

Answer 11

Papillary. (fibrovascular cores)
Acinar. (gland-forming)
Solid (w. intracytoplasmic mucus)

Question 12

Which NSCLC is most strongly associated with smoking?

Answer 12

Squamous cell carcinoma.

Question 13

Why is bronchiectasis a common problem in squamous cell carcinoma of the lung?

Answer 13

2/3 of squamous cell carcinomas are central, and cause airway obstruction -> post-obstructive PNA, bronchiectasis.

Question 14

2 histologic features of a lung cancer that suggest squamous cell differentiation?

Answer 14

Keratinization.

Intercellular bridges.

Question 15

Pre-invasive lesion of squamous cell carcinoma?

Answer 15

Carcinoma in situ (CIS).

Question 16

What’s a NSCLC without squamous or glandular differentiation?

Answer 16

Large cell carcinoma.

large cells with eosinophilic cytoplasmic, ugly nuclei

Question 17

What are the 2 main lung cancers associated with smoking?

Answer 17

Squamous cell carcinoma.

Small cell carcinoma.

Question 18

Small cell cancer is neuroendocrine… so are carcinoid tumors.

Answer 18

Okay.

Question 19

Gross features of small cell carcinoma?

Answer 19

Usually central lesions.

Lots of lymphadenopathy.

Question 20

What does small cell carcinoma look like histologically? (3 thigs)

Answer 20

Small cells (surprisingly) - about 2-3x a lymphocyte nucleus.
High N:C ratio.
Nuclei with salt & pepper chromatin.

Question 22

Where in the lung do carcinoid tumors like to go?

Answer 22

They tend to be central (90%) and endobronchial.

Question 23

What kind of symptoms do carcinoid tumors cause?

Answer 23

Obstructive symptoms (adult onset “asthma”), recurrent PNA, hemoptysis.

Question 24

Histologic appearance of carcinoid tumor growth pattern?

Cell appearance?

Answer 24

Nests, cords, ribbons.

Round, ovoid, or spindle shaped cells… uniform cell size, abundant cytoplasm, fine granular chromatin.

Question 25

What distinguishes an atypical from a typical carcinoid tumor?

Answer 25

of mitoses per high power field and necrosis: Typical: < 2 mitoses per 10 hpf, no necrosis. Atypical: 2-10 mitoses per 10 hpf and/or necrosis (atypical is higher grade)

Question 26

What's a pulmonary hamartoma?

Answer 26

A benign tumor composed of... disorganized mature tissues, including lots of cartilage, fat, smooth muscle, calcification.

Question 27

How do pulmonary hamartoma's appear on radiology?

Answer 27

Well-circumscribed, solitary nodules, with calcifications ("popcorn calcifications")

Question 28

What do you call tumors arising from the pleura? | What about tumors of the pleura that come from elsewhere - where do they come from?

Answer 28

Mesothelial tumors are from pleura. Other tumors of pleura come from mesenchyme (esp. solitary fibrous tumors), lymphoproliferative disorders, and mets.

Question 29

Epidemiological association with malignant mesothelioma?

Answer 29

Asbestos exposure (and some other fibers) - with a long latency period (decades).

Question 30

What does malignant mesothelioma look like grossly?

Answer 30

Thick tumor encasing the lungs and in the fissures. | Causes effusions.

Question 31

Natural history of malignant mesothelioma?

Answer 31

Rapidly progressive and fatal.

Question 32

2 major histologic types of mesothelioma?

Answer 32

Epithelioid | Sarcomatoid

Question 33

Where do most solitary fibrous tumors arise?

Answer 33

In the visceral pleura,

Question 34

Gross appearance of solitary fibrous tumors?

Answer 34

Solitary, well-circumscribed, firm, whitish, whorled.

Question 35

Histologic appearance of solitary fibrous tumors?

Answer 35

Patternless.... with hypocellular and hypercellular areas. | Dense collagenous stroma with "spindle cells" that look like fibroblasts.

Question 36

Should you assume that effusions to the pleura are malignant?

Answer 36

No, you should confirm with cytology.

Question 37

From which organs do mets in the pleura most commonly originate?

Answer 37

Lung, breast, ovary

Question 38

3 structures of the anterior and superior mediastinum?

Answer 38

Thymus. Lymph nodes. Sometimes thyroid or parathyroid tissue.

Question 39

4 primary tumors of the anterior and superior mediastinum? | Recall that here, too, mets are more common than primary tumors.

Answer 39

``` The 4 T's: Thymoma. (Terrible) lymphoma. Teratoma (germ cell tumors), Thyroid or parathyroid conditions/tumors. ```

Question 40

3 ways a thymoma can present?

Answer 40

Asymptomatic. Immunologic effects. Local mass effect.

Question 41

Example of an immunologic effect of thymoma?

Answer 41

Mysasthenia gravis.

Question 42

In thymoma, what's the neoplastic cell?

Answer 42

Epithelial cells are the malignant cells. | Lymphocytes in the background are benign.

Question 43

Structures of the middle mediastinum?

Answer 43

Lymph nodes, trachea, bronchi. Heart and pericardium. Great vessels.

Question 44

Lesions of the middle mediastinum? | not just tumors

Answer 44

``` Mets. Lymphoma. Bronchogenic cysts. Pericardial cysts. Aortic aneurysm. ```

Question 45

Structures of the posterior mediastinum?

Answer 45

``` Nerves, autonomic ganglia, lymph nodes, fat. Esophagus. Descending thoracic aorta. Azygous veins. Thoracic duct. ```

Question 46

Lesions (not just tumors) of the posterior mediastinum?

Answer 46

``` Nerve sheath tumors (neurofibromas, Schwannoma). Esophageal cysts. Gastroenteric cysts. Thoracic duct cysts. Mets. Lymphomas. ```