Histological and immunohistochemical characterization of extranodal diffuse large-cell lymphomas with prominent spindle cell features.
OBJECTIVE
To describe five cases of diffuse large-cell lymphoma with prominent spindle cell components involving skin, nasal-ocular mucosa, and soft tissue. Because of the spindle cell morphology, such cases must be differentiated from true sarcomas arising in or metastasizing to soft tissue, skin, bone, lymph node, or other organs and sites.


RESULTS
Formalin-fixed paraffin-embedded archival tissue from five consultation cases of diffuse large-cell lymphoma with prominent spindle cell features involving the skin, nasal-ocular mucosa, and soft tissue in three male and two female patients was studied by histology and immunohistochemistry. Clinicopathological findings were also reviewed for all the patients. By morphology, initial evaluation of the cases suggested spindle cell sarcoma in two cases, inflammatory pseudotumour in one case, large-cell lymphoma in another case, and one case was considered suspicious for malignant lymphoma. Immunohistochemistry demonstrated a B-cell lineage in four of the spindle cell lesions, with a diagnosis of primary cutaneous CD30+ anaplastic large cell lymphoma made for the fifth case. Four of five cases also showed actin reactivity.


CONCLUSIONS
Although extremely rare, lymphomas with prominent spindle cell morphology can be encountered in daily surgical pathology practice, and should be included in the differential diagnosis of spindle cell lesions in skin and soft tissue. The observed actin reactivity in four of the five spindle cell lymphomas may lead to a misdiagnosis of leiomyosarcoma if lymphoid markers are not included in the immunohistochemical panel.
Wang
J
J
City of Hope National Medical Center, Department of Anatomic Pathology, Duarte, CA 91010, USA.
Sun
N C
NC
Nozawa
Y
Y
Arber
D A
DA
Chu
P
P
Chang
K L
KL
Weiss
L M
LM
D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000032:analysis; D018951:Antigens, CD20 / Q000032:analysis; D051925:CD79 Antigens; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017493:Leukocyte Common Antigens / Q000032:analysis; D016393:Lymphoma, B-Cell / Q000378:metabolism / Q000473:pathology*; D016403:Lymphoma, Large B-Cell, Diffuse / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011947:Receptors, Antigen, B-Cell / Q000032:analysis; D012509:Sarcoma / Q000378:metabolism / Q000473:pathology
D015703:Antigens, CD; D018951:Antigens, CD20; D051925:CD79 Antigens; C497881:CD79A protein, human; D011947:Receptors, Antigen, B-Cell; D017493:Leukocyte Common Antigens