[Clinicopathologic study of 15 splenectomy specimens of patients with hairy cell leukemia].
OBJECTIVE
To investigate the clinicopathologic features, diagnosis, differential diagnosis and the prognosis of hairy cell leukemia (HCL).


METHODS
Fifteen splenectomy specimens of HCL patients were investigated retrospectively using HE and immunohistochemistry in correlation with the follow-up information.


RESULTS
(1) The male to female ratio was 2.75:1, age ranged from 36 to 68 years with a median of 47 years. The most consistent clinical feature at presentation was marked splenomegaly (100%). Other symptoms included anemia (80.0%), thrombocytopenia (60.0%), leucocytosis (53.3%), pancytopenia (20.0%) and the absence of B-symptom. (2) The proportion of hairy cells was (14.6 +/- 7.2)% in periphery blood and (47.3 +/- 23.8)% in bone marrow. The positive rate of TRAP assay was 62.5% in bone marrow; 85.7% for TPA test and the detection rate for RLC was 25% by transmission electric microscopy. The frequency of bone marrow involvement was 100%. (3) The average weight of 15 spleens was (3012 +/- 1974) g. The size of 6 spleens ranged from 16 cm x 10 cm x 5 cm to 32 cm x 20 cm x 14 cm. The white pulp of spleen showed a characteristic atrophy feature or even absent due to leukemic infiltration, predominantly involving the red pulp with some sinusoidal pattern. "Blood pool" change was an infrequent feature (3/15 cases). The nuclei of leukemic cells were round (13 cases) or bean-shaped (2 cases), nucleoli inconspicuous or disappeared. The abundant cytoplasm and prominent cell border resulted in a "fried egg" appearance. By immunohistochemistry, leukemic cells were positive for CD45RA, CD20, PAX-5, CD25, CD11c, Annexin A1 and cyclinD1, but negative for CD3 and CD43. (4) 13 cases (86.7%) have been followed-up and all are alive. Among them, 9 cases are living well more than 5 years and 7 more than 10 years.


CONCLUSIONS
Splenomegaly is frequently the first manifestation of patients with HCL and occurred predominantly in the middle to elderly adults. Definite diagnosis of HCL requires a combined histological and immunohistochemical assessment of the splenectomy specimen, bone marrow biopsy and aspirate.
Li
Zhan-qi
ZQ
Department of Pathology, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences, Tianjin 300020, China.
Chen
Hui-shu
HS
Liu
En-bin
EB
Sun
Qi
Q
Fang
Li-huan
LH
Sun
Fu-jun
FJ
Zhang
Pei-hong
PH
Yang
Qing-ying
QY
Qiu
Lu-gui
LG
D000328:Adult; D000368:Aged; D017305:Annexin A1 / Q000378:metabolism; D018951:Antigens, CD20 / Q000378:metabolism; D039521:CD11c Antigen / Q000378:metabolism; D051925:CD79 Antigens / Q000378:metabolism; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism; D007943:Leukemia, Hairy Cell / Q000378:metabolism* / Q000473:pathology* / Q000601:surgery; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000378:metabolism / Q000473:pathology; D015463:Leukemia, Prolymphocytic / Q000378:metabolism / Q000473:pathology; D017493:Leukocyte Common Antigens / Q000378:metabolism; D018442:Lymphoma, B-Cell, Marginal Zone / Q000378:metabolism / Q000473:pathology*; D008224:Lymphoma, Follicular / Q000378:metabolism / Q000473:pathology; D020522:Lymphoma, Mantle-Cell / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013154:Spleen / Q000473:pathology*; D013156:Splenectomy; D015996:Survival Rate
D017305:Annexin A1; D018951:Antigens, CD20; D039521:CD11c Antigen; D051925:CD79 Antigens; D019394:Ki-67 Antigen; D017493:Leukocyte Common Antigens