Pathology of Soft Tissue Flashcards
(44 cards)
1
Q
*** What is DERMATOMYOSITIS?
A
- inflammatory disorder of the skin and skeletal muscle
- unknown etiology.
2
Q
With what are some cases of dermatomyositis associated?
A
- gastric carcinoma
3
Q
What are the clinical features of dermatomyositis?
A
- bilateral PROXIMAL muscle weakness (can’t raise arm to comb hair), but distal can develop late in the disease.
- rash of the UPPER EYELIDS (HELIOTROPE RASH) or MALAR rash.
- red papules on the elbows, knuckles, and knees (GOTTRON PAPULES).
4
Q
What lab findings will you see in dermatomyositis?
A
- increased creatinine kinase (enzyme found in muscle, which will leak out into the blood when damaged).
- positive ANA and anti-Jo-1 antibody (hallmark of this disease).
- PERIMYSIAL inflammation (CD4+ T cells) with PERIFASICULAR atrophy
5
Q
How do you remember perimysial inflammation for dermatomyositis vs. endomysial inflammation for polymyositis?
A
- peri= outside and closer to the skin (dermatomyositis)
6
Q
How do you treat dermatomyositis?
A
- corticosteroids
7
Q
** What is POLYMYOSITIS?
A
- inflammatory disorder of skeletal muscle.
- resembles dermatomyositis clinically, but SKIN is NOT involved.
- will see ENDOMYSIAL inflammation (CD8+ T cells) with necrotic muscle fibers.
8
Q
** What is X-linked Duchenne muscular dystrophy? (PICMONIC)
A
- degenerative disorder due to SPONTANEOUS DELETIONS of the DYSTROPHIN gene, characterized by muscle wasting and REPLACEMENT of SKELETAL MUSCLE with ADIPOSE tissue.
9
Q
What is the role of dystrophin?
A
- anchoring the muscle cytoskeleton to the extracellular matrix.
10
Q
What is the largest gene in the human genome?
A
- dystrophin gene
11
Q
How do babies (usually boys bc X-linked recessive) present with Duchenne muscular dystrophy?
A
- PROXIMAL muscle weakness at 1 year of age, then progresses to distal muscles.
- CALF PSEUDOHYPERTROPHY
- elevated serum CREATINE KINASE.
12
Q
What causes death in Duchenne muscular dystrophy?
A
- cardiac or respiratory failure; myocardium is usually involved.
13
Q
*** What is Becker Muscular Dystrophy?
A
- MUTATED dystrophin gene, rather than deleted
- milder disease.
14
Q
** What is MYASTHENIA GRAVIS? (PICMONIC)
A
- autoantibodies against the POSTSYNAPTIC ACETYLCHOLINE RECEPTOR at the neuromuscular junction.
- more commonly seen in women.
15
Q
What are the clinical features of myasthenia gravis?
A
- muscle weakness that WORSENS with USE (bc you are using up the acetylcholine stores available) and improves with rest; classically involves the EYES, leading to PTOSIS and DIPLOPIA (double vision).
16
Q
Will myasthenia gravis symptoms improve or worsen with acetylcholinesterase inhibitors?
A
- IMPROVE bc there will be more acetylcholine around for a longer period of time.
17
Q
** With what other condition myasthenia gravis associated?
A
- thymic hyperplasia or thymoma
* thymectomy improves symptoms.
18
Q
** What is LAMBERT-EATON SYNDROME? (PICMONIC)
A
- antibodies against PRESYNAPTIC CALCIUM CHANNELS at the NMJ.
- arises as a PARANEOPLASTIC SYNDROME (usually due to small cell lung carcinoma).
- leads to IMPAIRED acetylcholine release bc firing of presynaptic Ca2+ channels is required for acetylcholine release.
19
Q
What are the clinical features of lambert-eaton syndrome?
A
- PROXIMAL muscle weakness that IMPROVES with USE bc more calcium can kick off the antibody.
20
Q
Are eyes affected or spared in lambert-eaton syndrome?
A
- spared
21
Q
Will anticholinesterase (acetylcholinesterase inhibitors) improve symptoms of lambert eaton syndrome?
A
- NO bc there is no acetylcholine around.
22
Q
Does lambert-easton syndrome resolve with resection of the tumor?
A
- YES
23
Q
*** What is a LIPOMA?
A
- BENIGN tumor of ADIPOSE tissue.
- most common benign soft tissue tumor in adults.
24
Q
*** What is LIPOSARCOMA?
A
- MALIGNANT tumor of ADIPOSE tissue.
- most common malignant soft tissue tumor in adults.
25
What is the characteristic cell of liposarcoma?
- lipoblast
26
*** What is a RHABDOMYOMA?
- BENIGN tumor of SKELETAL MUSCLE.
27
*** With what is cardiac rhabdomyoma associated?
- tuberous sclerosis
28
*** What is a RHABDOMYOSARCOMA?
- MALIGNANT tumor of SKELETAL MUSCLE.
| - most common malignant soft tissue tumor in CHILDREN (EMBRYONAL).
29
What is the characteristic cell in rhabdomyosarcoma?
- rhabdomyoblast
| * DESMIN positive
30
**** What is the most common site for rhabdomyosarcoma?
- head and neck
| * vagina is classic site in young girls.
31
What is neurogenic muscle atrophy?
- muscle atrophy due to deprivation of innervation
| - symptoms may be milk weakness to respiratory failure.
32
What is nodular fasciitis?
- reactive fibroblastic proliferation of tissue.
- comprised of plump immature fibroblastic cells.
* simple excision is curative.
33
What are fibromatoses?
- group of benign soft tissue tumors, with a histology consistent with proliferation of well-differentiated fibroblasts, an infiltrative growth pattern, and aggressive clinical behavior with frequent local recurrence.
- may be superficial or deep.
34
** What are Fibrosarcomas?
- malignant fibroblast tumors that are unencapsulated, infiltrative FISH FLESH MASSES.
- HERRINGBONE pattern.
- plump spindle shaped cells.
- metastatsize HEMATOGENOUSLY.
35
What is a fibrous histiocytoma (dermatofibroma)?
- benign well defined mobile nodule in the dermis or subcutaneous tissue.
- Tan papule.
- made of interlacing spindle cells in the dermis. Histiocytes may be present in the spindle component.
- a CLEAR ZONE separates the mass from the epidermis.
36
How do you treat a fibrous histiocytoma (dermatofibroma)?
- local excision
37
What is dermatofibrosarcoma protuberans?
- intermediate between benign fibrohistiocytic tumors and malignant fibrohistiocytomas.
- polypoid and multinodular
- slow growing lesion in dermis and subcutaneous tissue.
- fibroblastic spindle shaped cells in a STORIFORM or CARTWHEEL pattern.
38
What is malignant fibrous histiocytoma?
- most common soft tissue sarcoma in adults and post-irradiation sarcoma.
- deep tissue of extremities and retroperitoneal area.
- highly aggressive.
39
How does the ALVEOLAR rhabodmyosarcoma differ from the embryonal rhabdomyosarcoma?
- alveolar has a network of fibrous septae that divide cells into clusters, which look like pulmonary alveoli.
* cross striations are not common (where they are in embryonal).
40
*** What is a Schwannoma?
- benign tumor of Schwann cells. Grow next to the nerve but do NOT invade it.
- involves cranial or spinal nerves. Within the cranium, most frequently involves cranial nerve VIII at the cerebellopontine angle (presents as LOSS of HEARING and tinnitis).
- positive for S-100
- bilateral tumors are seen in neurofibromatosis type 2.
- loss of NF2 gene product (MERLIN)
41
What are ANTONI A vs. B areas in Schwannomas?
- Antoni A= dense areas containing spindle cells arranged into intersecting fasicle. Also have VEROCAY BODIES (nuclei next to nuclear free zones).
- Antoni B= loose, hypocellular areas with spindle cells spread apart by extracellular matrix.
42
Can Schwannomas compress nerves?
- YES
43
** What is a neurofibroma?
- benign nerve sheath tumors composed of spindle cells.
- Schwann cells, mixed with perineural-like cells, fibroblasts, mast cells, and CD34+ spindle cells.
- also positive for S-100.
- AXONS run through the neoplasm (won't see this in Scwhannoma).
44
What is a synovial sarcoma?
- malignant tumor around the joint space, but does NOT arise from synovial cells; it arises from MESENCHYMAL cells around the joint.
- RARE
- BIPHASIC PATTERN= epithelial and spindle cell components.
