Diagnosis: Anaplastic Large Cell Lymphoma, ALK positive
Key Histopathologic Features
•Hallmark cells: Horseshoe or Kidney shaped nuclei, abundant cytoplasm
•Most cases, CD30+, ALK+, EMA+ ,CD45+, sCD3-, CD15-, CD4+, CD43+, CD25+, CD2+, CD5+, TIA1+, granzyme B+, perforin+
Key Histopathologic Features
•Hallmark cells: Horseshoe or Kidney shaped nuclei, abundant cytoplasm
•Most cases, CD30+, ALK+, EMA+ ,CD45+, sCD3-, CD15-, CD4+, CD43+, CD25+, CD2+, CD5+, TIA1+, granzyme B+, perforin+
WHO book, 4th edition.
CLINICAL FEATURES
3% of adult NHL and 10-30% of children lymphomas;
ALK+ ALCL,mostly <30 YO, good prognosis;
ALK- ALCL mostly elder patients, poor prognosis;
MICROSCOPIC FINDINGS
Highly pleomorphic, eccentric, horse-shoe or kidney-shaped nuclei with an eosinophilic region near the nucleus (hallmark cells)
Cytoplasm: abundant, clear, basophilic or eosinophilic
Chromatin: finely clumped or dispersed with multiple small/prominent basophilic nucleoli
SUBTYPES
Common type (70%).
Sheets of large, pleomorphic tumor cells with an abundant cytoplasm
In imprint preparations, the cytoplasm show numerous vacuoles
Nucleus:horse-shoe or kidney-shaped, and usually multiple small basophilic nucleoli, `hallmark cells'
Lymphohistocytic type (10%):
A large number of pale reactive histiocytes, plasma cells and lymphocytes
Small cell type (5-10%):
Mixture of large, medium-sized and small pleomorphic tumour cells, large anaplastic cells: a minority, cluster around small vessels
Small and medium-sized cells: dominant population, clear cytoplasm, irregular nucleus, possible negative or weakly positive for CD30
Hodgkin'-like' ALCL:
Capsular thickening and a vaguely nodular fibrosis, tumor cells resembling classic Hodgkin and Reed-Sternberg cells
Giant cell rich type: many of the tumour cells contain more than one nucleus.
Sarcomatoid type: large, bizarre, spindle-shaped tumour cells: mimic a soft tissue sarcoma
Neutrophil-rich type: may mimic an acute inflammation
Signet-ring type
CLINICAL FEATURES
3% of adult NHL and 10-30% of children lymphomas;
ALK+ ALCL,mostly <30 YO, good prognosis;
ALK- ALCL mostly elder patients, poor prognosis;
MICROSCOPIC FINDINGS
Highly pleomorphic, eccentric, horse-shoe or kidney-shaped nuclei with an eosinophilic region near the nucleus (hallmark cells)
Cytoplasm: abundant, clear, basophilic or eosinophilic
Chromatin: finely clumped or dispersed with multiple small/prominent basophilic nucleoli
SUBTYPES
Common type (70%).
Sheets of large, pleomorphic tumor cells with an abundant cytoplasm
In imprint preparations, the cytoplasm show numerous vacuoles
Nucleus:horse-shoe or kidney-shaped, and usually multiple small basophilic nucleoli, `hallmark cells'
Lymphohistocytic type (10%):
A large number of pale reactive histiocytes, plasma cells and lymphocytes
Small cell type (5-10%):
Mixture of large, medium-sized and small pleomorphic tumour cells, large anaplastic cells: a minority, cluster around small vessels
Small and medium-sized cells: dominant population, clear cytoplasm, irregular nucleus, possible negative or weakly positive for CD30
Hodgkin'-like' ALCL:
Capsular thickening and a vaguely nodular fibrosis, tumor cells resembling classic Hodgkin and Reed-Sternberg cells
Giant cell rich type: many of the tumour cells contain more than one nucleus.
Sarcomatoid type: large, bizarre, spindle-shaped tumour cells: mimic a soft tissue sarcoma
Neutrophil-rich type: may mimic an acute inflammation
Signet-ring type