Dermatofibroma-like granular cell tumour: a potential diagnostic pitfall

Abstract

Dermatofibroma-like granular cell tumour (GCT) is a rare entity, with only two cases having been described so far. We report another case in a 62-year-old woman, discuss histopathological features, and review other tumours in which granular changes have been observed. Our tumour was composed predominantly of oval-to-spindle granular cells with prominent nucleoli, arranged in short fascicles and storiform pattern, infiltrating around collagen bundles. Immunohistochemical analysis with antibodies against CD31, CD56, CD68, CD117, S-100 protein, inhibin, calretinin, EMA, p53 and MIB-1 was performed, showing expression of CD56, CD68, S-100 protein, inhibin and calretinin. The diagnosis of atypical dermatofibroma-like GCT was made.

Desmoplastic stromal changes in cutaneous neural granular cell tumors: An under‐recognized histopathologic feature of diagnostic and prognostic importance

“…Four tumors morphologically similar to the two cases with widespread spindling presented herein have been reported in the literature as “dermatofibroma‐like GCT,” “dermatofibroma‐like atypical GCT,” and “desmoplastic atypical GCT” (Table ) . Clinical follow‐up was available on two of these four cases, both of which showed no evidence of local recurrence following complete excision.…”

Granular cell dermatofibroma: A potential diagnostic pitfall

“…Our case presented a hard diagnosis because the tumour mass was made up of more than 85% of granular cells. Morphology of lesions could be a great help in differential diagnosis by comparing with the benign granular cell tumour (GCT), which differs (GCDF) for the different histogenesis: in fact, an immunohistochemical study with antibodies against the S-100 protein was strongly and diffusely positive in benign granular cell tumour, but negative in GCDF, conversely CD68 will be positive in GCDF and almost totally negative in GCT [6][7][8]. Differential diagnosis with granular cell malignancy is less apparently complex, since it has evident mitosis and cytological atypia, which could lead to the suspicion that it may be a malignant entity distinct from GCDF.…”

Granular Cell Dermatofibroma: When Morphology Still Matters

“…Our case represents a difficult diagnosis because the tumor mass is made up of more than 85% of granular cells. Morphology of lesions could be a great help in differential diagnosis involving comparisons with the benign granular cell tumor (GCT), which differs from granular cell dermatofibroma (GCDF) by the different histogenesis: in fact, an immunohistochemical study with antibodies against the S-100 protein is strongly and diffusely positive in benign granular cell tumor, but negative in GCDF, just as CD68 will be positive in GCDF and almost totally negative in GCT [7,8].…”