ORAL DESMOPLASTIC GRANULAR CELL TUMOR: PRESENTATION OF A RARE VARIANT.

Background

Granular Cell Tumor (GCT) is a benign soft tissue neoplasm that shows a predilection for the dorsal tongue. Desmoplastic GCT (DGCT) represents an unusual histopathologic variant, most often observed on skin and only rarely seen intraorally. Herein, we present a case of oral DGCT and discuss the role of desmoplasia in the diagnosis and biologic behavior of this rare lesion.

Case Description

A 47-year-old male presented for evaluation of a tongue mass first noticed 10 days ago. Clinical examination revealed a painless, well-circumscribed, broad-based, elastic, submucosal tumor covered by normal mucosa, on the posterior dorsal surface of the tongue. With a provisional diagnosis of GCT or other soft tissue tumor, an excisional biopsy was performed. Histopathologically, variably-sized scattered syncytial aggregates of large polygonal or spindle-shaped cells with abundant eosinophilic, granular cytoplasm and small vesicular nuclei were observed, set in a densely collagenized connective tissue stroma; close proximity of neoplastic cells to skeletal musculature was also noted at the surgical margins, while the lesion was nonencapsulated, covered by hyperplastic epithelium. Immunohistochemical evaluation showed S-100 focal positivity, while EMA and GFAP stains were negative. A diagnosis of DGCT was rendered.

Discussion and Conclusions

Stromal desmoplasia usually develops as a reaction to local trauma, whereas it may also be seen in various neoplasms. Desmoplasia in cutaneous DGCT has been attributed to chronicity; further, the tongue is a common site of injury, which could possibly provoke the desmoplastic changes observed. A better clinicopathologic characterization of this rare GCT variant is warranted.