Background
Cases presentation
Case 1
Case 2
Discussion
Neoplasm | Clinical features | Morphology | Immunophenotype | Molecular features |
---|---|---|---|---|
B-LBL
| median age 20 years, M > F, 90% of cases present as B-ALL | convoluted or round nuclear contours; immature blastic chromatin; numerous mitotic figures | CD19 +, PAX-5 +, CD20 +/−, TdT +, CD10 +/−, CD79 + (in 10% of cases), T-cell antigens - | monoclonal IgH gene rearrangement; t (9; 22) (q34; q11.2); t (12;21) (p13; q22); t (v; 11q23); t (1; 19) (q23; p13.3); t (5; 14) (q31; 32) |
BL
| childhood; head and neck and ileocecal region frequently involved | prominent “starry sky” pattern; monotonous, medium-sized cells with 2–5 prominent nucleoli and distinct cytoplasmic rim; very high mitotic and apoptotic rates | CD10 +, CD19 +, CD20 +, CD79a +, Bcl2 -, Bcl6 +, TdT -, Ki-67 > 99%, T-cell antigens - | monoclonal IgH gene rearrangement; t (8; 14) (q24; q32) or t (2; 8) (p11; q24) or t (8; 22) (q24; q11) involving MYC |
DLBCL
| adult; frequent nodal involvement | large or medium-sized cells with prominent nucleoli; centroblastic or immunoblastic appearance | CD19+, CD20+, CD79a+, PAX-5+, CD10 +/−, Bcl6 +/−, IRF4/MUM1 +/−, Bcl2 +/−, TdT -, T-cell antigens - | t (14; 18) (q32; q21); Bcl6 (3q27) rearrangement; MYC (8q24) rearrangement |
Myeloid sarcoma
| median age; frequent history of previous or concomitant AML, MDS, MPN, MDS/MPN | myelocytes with more distinct and eosinophilic cytoplasm | CD43 +, CD68PGM1 +, CD68 +, CD117 +, MPO +, CD10 -, T-cell antigens - | no evidence of monoclonal TCR gene rearrangements, monosomy 7, trisomy 8 |
Blastoid variant of MCL
| median age 68 years, male predominance; frequent extranodal involvement | lymphoblastoid cells with immature chromatin and high mitotic rate | CD19 +, CD20 +, Cyclin-D1 +, CD5 +, CD10 -, TdT -, CD2 -, CD3 -, CD7 - | monoclonal IgH gene rearrangement; no evidence of monoclonal TCR gene rearrangements; t (11; 14) (q13; q32) |
ES/
PNET
| median age <20 years, M > F; frequent bone involvement | cohesive growth pattern, frequently pseudorosettes formation; small blue monomorphic round cells with fine nuclear chromatin, round nuclei and scanty clear cytoplasm | CD99 +, vimentin +, WT-1 +, lymphoid markers - | no evidence of monoclonal TCR gene rearrangement; t (11; 22) (q24; q12) or t (21; 22) (q22; q12) or t (1; 16) (q11; q11) |
Alveolar rhabdomyosarcoma
| adolescents and young adults; extremities and paraspinal region frequently involved | nests of round cells separated by fibrous septa, with some giant cells and occasional clear cells | vimentin, desmin, smooth muscle actin, HHF-35, MyoD1, myogenin +, cytokeratins +/−, S100 +/−, CD20 +/−, T-cell antigens -, TdT- | t (2; 13) (q35; q14) or t (1;13) (p36; q14) |
Small
(oat)
cell carcinoma
| middle age; frequent pulmonary invlvement | small ovoid, round to spindled cells with markedly increased nuclear-to-cytoplasmic ratio, hypercromatic nuclei and inconspicuous nucleoli | low molecular weight keratins +, chromogranin +/−, synaptophysin +/−, CD3 -, CD5 -, TdT - | |
Seminoma
| young adults; testicular enlargement and hydrocele | round, polygonal cells with large and vesicular nuclei, prominent nucleoli, clear and eosinophilic cytoplasm and frequent mitoses, lymphoid infiltrate in the backgournd | CD117 +, D2-40 +, OCT4 +, SALL4 +, cytokeratins -, CD30 -, EMA -, T-cell antigens -, TdT - |