Serous effusion cytology of extranodal natural killer/T-cell lymphoma.
OBJECTIVE
Extranodal natural killer/T-cell lymphoma, nasal type (ENKTCL-N), is a rare form of lymphoma that typically occurs at extranodal sites. It is one of the most common extranodal lymphomas in China. Literature on effusions and cytological findings relating to ENKTCL-N is limited. We studied five consecutive cases of ENKTCL-N effusions collected over a 3-year period. The cytomorphological, immunocytochemical and molecular biological features were evaluated with literature review. The purpose of this study is to discuss how to diagnose ENKTCL-N cytologically in effusions.


METHODS
Smears and cell block sections were reviewed for each case. Immunocytochemistry was performed on 4-μm paraffin sections. Antibodies used were as follows: cCD3 (intracytoplasmic CD3), CD45RO, surface CD3, CD20, CD79a, CD56, TIA-1, granzyme B, CD30, CD99, TdT and Ki-67. In situ hybridization for EBER1/2 (EBER-ISH) and T-cell receptor γ (TCRγ) gene rearrangement were performed for all cases.


RESULTS
Large to medium-sized tumour cells with pleomorphic nuclei and coarse chromatin were found in a necrotic background in all cases. The cytoplasm of the tumour cells was scant to moderately abundant with occasional cytoplasmic projections; in Giemsa-stained smears, fine granules were present in some tumour cells. Mitotic figures were frequent. The tumour cells were all positive for CD56, granzyme B, TIA-1 and cCD3, and were negative for surface CD3, CD20 or CD79a, CD99 and TdT. The MIB index was 50-80%. Epstein-Barr virus-encoded RNA (EBER) hybridizing signals were detected for most neoplastic cells. The T-cell receptor gamma gene rearrangement analysis showed germ-line configuration, except for one case.


CONCLUSIONS
Effusion cytology may be appropriate for establishing the diagnosis of ENKTCL-N, particularly for patients in whom tissue biopsy is not possible.
Department of Pathology, West China Hospital of Sichuan University, Chengdu, China.
X-Y
XY
Su
J
J
Huang
Y
Y
Jiang
Y
Y
Tang
G-D
GD
Li
W-P
WP
Liu
D000328:Adult; D000368:Aged; D001826:Body Fluids / Q000166:cytology*; D003584:Cytological Techniques / Q000379:methods*; D005260:Female; D004854:Herpesvirus 4, Human / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D016130:Immunophenotyping; D054391:Lymphoma, Extranodal NK-T-Cell / Q000473:pathology* / Q000821:virology; D008297:Male; D008875:Middle Aged; D055815:Young Adult