Primitive polypoid granular-cell tumor and other cutaneous granular-cell neoplasms of apparent nonneural origin

Am J Surg Pathol. 1991 Jan;15(1):48-58. doi: 10.1097/00000478-199101000-00006.


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.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Carcinoma / genetics
  • Carcinoma / pathology*
  • Carcinoma / ultrastructure
  • Child
  • Female
  • Granuloma / genetics
  • Granuloma / pathology*
  • Humans
  • Immunophenotyping
  • Male
  • Microscopy, Electron
  • Middle Aged
  • Neoplasms, Muscle Tissue / genetics
  • Neoplasms, Muscle Tissue / pathology*
  • Neoplasms, Muscle Tissue / ultrastructure
  • Polyps / genetics
  • Polyps / pathology
  • Polyps / ultrastructure
  • Skin Neoplasms / genetics
  • Skin Neoplasms / pathology*
  • Skin Neoplasms / ultrastructure