Granular cell tumor in an unusual location affecting a pediatric patient: case report

Granular cell tumor (GCT) is a rare benign soft-tissue neoplasm of Schwann-cell origin. It most often affects the tongue, followed by floor of the mouth and buccal mucosa, mainly in adult women. A 13-year-old male patient was referred for evaluation of a lesion on the upper lip. Intraoral examination showed a painless sessile nodule, normal color, measuring 1.0 × 0.5 cm, with several months of evolution. Diagnostic hypotheses included neurofibroma, pleomorphic adenoma, and canalicular adenoma. An excisional biopsy was performed, and histopathologic analysis revealed a well-defined proliferation of eosinophilic granular cells, with no typical pseudo-epitheliomatous hyperplasia, and perineural involvement. Immunohistochemistry showed positivity for vimentin, S100, CD56, and CD68. The diagnosis was GCT. After one year of follow-up, the patient showed no signs of recurrence or alterations. GCT is extremely rare, affecting the upper lip in pediatric patients; therefore, it should be considered in the differential diagnosis of lip nodular lesions. Granular cell tumor (GCT) is a rare benign soft-tissue neoplasm of Schwann-cell origin. It most often affects the tongue, followed by floor of the mouth and buccal mucosa, mainly in adult women. A 13-year-old male patient was referred for evaluation of a lesion on the upper lip. Intraoral examination showed a painless sessile nodule, normal color, measuring 1.0 × 0.5 cm, with several months of evolution. Diagnostic hypotheses included neurofibroma, pleomorphic adenoma, and canalicular adenoma. An excisional biopsy was performed, and histopathologic analysis revealed a well-defined proliferation of eosinophilic granular cells, with no typical pseudo-epitheliomatous hyperplasia, and perineural involvement. Immunohistochemistry showed positivity for vimentin, S100, CD56, and CD68. The diagnosis was GCT. After one year of follow-up, the patient showed no signs of recurrence or alterations. GCT is extremely rare, affecting the upper lip in pediatric patients; therefore, it should be considered in the differential diagnosis of lip nodular lesions.