Primitive polypoid granular-cell tumor and other cutaneous granular-cell neoplasms of apparent nonneural origin.
Most cutaneous and noncutaneous granular-cell tumors are currently thought to be of Schwann-cell derivation. We present seven unusual cutaneous granular-cell lesions in which Schwann-cell origin can be excluded or is inapparent. Four of these lesions are of a previously undescribed type, and, unlike conventional granular-cell tumors of the skin, show a polypoid configuration, numerous mitoses, cytologic atypia, and a primitive immunophenotype. We propose the term "primitive polypoid granular-cell tumor" for these lesions. One occurred in a child, and three in adults. There have been no metastases to date, with follow-up periods of 2, 4, 4, and 16 years, respectively, although one tumor recurred locally. Additional cases and longer follow-up may be required to rule out the possibility that primitive polypoid granular-cell tumor is a low-grade malignancy. Two other granular-cell lesions represent variants of leiomyosarcoma, one of which widely metastasized. The last case is a granular-cell form of nodular basal-cell carcinoma. Cutaneous granular-cell neoplasms can show varying differentiation and behavior. Pathologists should not equate the occurrence of cytoplasmic granularity in a cutaneous neoplasm with the diagnosis of granular-cell schwannoma.
LeBoit
P E
PE
Department of Pathology, University of California, San Francisco 94143-0506.
Barr
R J
RJ
Burall
S
S
Metcalf
J S
JS
Yen
T S
TS
Wick
M R
MR
D000328:Adult; D002277:Carcinoma / Q000235:genetics / Q000473:pathology* / Q000648:ultrastructure; D002648:Child; D005260:Female; D006099:Granuloma / Q000235:genetics / Q000473:pathology*; D006801:Humans; D016130:Immunophenotyping; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D009379:Neoplasms, Muscle Tissue / Q000235:genetics / Q000473:pathology* / Q000648:ultrastructure; D011127:Polyps / Q000235:genetics / Q000473:pathology / Q000648:ultrastructure; D012878:Skin Neoplasms / Q000235:genetics / Q000473:pathology* / Q000648:ultrastructure