Ki-1-positive anaplastic large-cell lymphoma (ALCL) is an uncommon neo
plasm which may present with extranodal as well as nodal disease. By d
efinition, the tumor cells are immunoreactive for Ki-1 or Ber-H2 antig
en (CD30). There have been few published cytologic descriptions of thi
s lymphoma, or of its detection in extranodal sites. We describe the c
ytologic findings in five cases of extranodal Ki-1 lymphoma. Cytologic
findings in all five cases were similar and consisted of a heterogene
ous population of lymphocytes and bizarre, pleomorphic tumor cells. Th
ese cells were characterized by generous amounts of vacuolated, basoph
ilic cytoplasm, eccentric, multilobulated nuclei with some showing ''w
reath-like'' configurations. Some nuclei contained huge nucleoli simul
ating Reed-Sternberg cells. A II cases showed the characteristic surfa
ce membrane and cytoplasmic paranuclear dot-like staining for CD30. Ou
r findings indicate that fine-needle aspiration and exfoliative cytolo
gy have a useful role in the diagnosis of Ki-1 ALCL in extranodal site
s. Furthermore, effusions containing anaplastic cells suspicious for l
ymphoma, particularly in AIDS patients, should be immunostained with a
ntibodies to CD30. (C) 1996 Wiley-Liss, Inc.