Histopathology Variants/Subtypes

Question 1

Amyloid:

Answer 1

• Immunocyte dyscrasias w/ amyloidosis (primary amyloidosis)-­‐ AL (as in multiple myeloma with light chain, mostly λ)
• Reactive systemic amyloidosis (secondary amyloidosis)-­‐ AA (seen in chronic inflammatory conditions)
• Hemodialysis assoc. amyloidosis-­‐ Aβ2m (β2 microglobulin-­‐ seen in renal failure)
• Hereditary amyloidosis-­‐ AA (Familial mediterranean fever)
• Systemic senile amyloidosis-­‐ ATTR (transthyretin)
• Senile cerebral-­‐ AB (Alzheimer disease)
• Medullary Ca of the thyroid-­‐ ACal (Calcitonin)

Question 2

Chondrosarcomas: (Chondrosarcs Will Make Many People Dead Rot)

Answer 2

• Clear cell
• Well diff.
• Myxoid
• Mesenchymal
• Periosteal
• De-­‐differentiated
• Round cell

Question 3

Hodgkin’s lymphoma

Answer 3

• Nodular, lymphocyte predominant (popcorn cell). Best prognosis.
• Lymphocyte rich: sheets of lymphocytes
• Nodular sclerosis (most common). Best prognosis. More in females, 2nd decade. RSC=“Lacunar cells”
• Mixed cellularity
• Lymphocyte depletion: most aggressive. Numerous RSC, few lymphocytes
• Unclassifiable

Question 4

Lipomas (most are M>F):

Answer 4

• Classic
• Angiolipoma (painful; exhibits fibrin thrombi in the vessels; assoc. w/ tuberous sclerosis, along with angiofibromas of the face and periungual fibromas)
• Hibernoma (11q13-­‐21) (S100+, CD34-­‐)
• Chondrolipoma (F>M)
• Angiomyolipoma (“moth eaten” smooth muscle cells; these are the renal lesions found in
  tuberous sclerosis)
• Lipoblastoma (8q11-­‐13); M>F
• Leiolipoma
• Lipomatosis
• Myolipoma
• Myelolipoma
• Spindle cell (Δ16q13; CD34+) (can have myxoid background)
• Pleomorphic (Δ16q13); M»F; CD34+; spindle cells + bizarre giant cells (floret-­‐like)
• Intramuscular: more deeply situated, infiltrative growth pattern between muscle bundles

Question 5

Liposarcs (M>F):

Answer 5

• Myxoid (most common form in the H&N; t(12;16 & 12;22)) (“chickenwire”)
• Round cell (t(12;16 & 12;22))
• Pleomorphic
• Well differentiated/ATL
• De-­‐differentiated

Question 6

Unknown malignancies

Answer 6

• Keratin
• Desmin, vimentin, myo-­‐D1 and myogenin (mesenchymal/skeletal muscle)
• SMA
• S-­‐100, synaptophysin, chromogranin, NSE
• HMB45, MelanA, Mart-­‐1
• CD45, CD3, CD20