Cutaneous granular cell tumor clinically mimicking ectopic breast diagnosed on fine needle aspiration cytology

Abstract

Granular cell tumor (GCT) is a rare benign neoplasm of Schwannian origin which accounts of 0.5% of soft tissue tumors. Although the most common site for GCT is tongue, it can occur at any site. GCT presenting as cutaneous nodule is rare, however cases have been reported in literature. We hereby document a case of 30 year female with a hyper‐pigmented cutaneous nodule of anterior chest wall on the milk‐line mimicking as an ectopic breast, diagnosed as GCT on fine needle aspiration cytology. We also add a note on the differential diagnoses of GCT with differentiating cytological features to emphasize on the correct diagnosis of GCT pre‐operatively.

Solitary pigmented nodule on the trunk: What is your diagnosis?

“…It appears as a slowly growing asymptomatic, solitary, skin-colored or rarely pigmented nodule with a smooth or slightly rough surface. 1 Occasionally, tenderness is described, like in our case. Differential diagnoses of skin adnexal tumor, dermatofibromas, and neurofibromas may be considered.…”

“…1 Malignant cases are exceedingly rare (1%-3%). 1 Clinical diagnosis of GCT is difficult and not usually considered. It appears as a slowly growing asymptomatic, solitary, skin-colored or rarely pigmented nodule with a smooth or slightly rough surface.…”

“…It is considered a neural tumor derived from Schwann cells, since it stains positively for S100 and other neural markers. It is more frequently located on the tongue, but it can occur at any site 1 1 .…”

“…Granular cell tumors, also known as Abrikossoff's tumor is a rare benign neoplasm, accounting for only 0.5% of all soft tissue neoplasms, that is, usually seen in the fourth to sixth decades of life. 1 It is considered a neural tumor derived from Schwann cells, since it stains positively for S100 and other neural markers. It is more frequently located on the tongue, but it can occur at any site.…”

“…It is more frequently located on the tongue, but it can occur at any site. 1 Malignant cases are exceedingly rare (1%-3%). 1 Clinical diagnosis of GCT is difficult and not usually considered.…”