Oral benign fibrous histiocytoma in a pediatric patient: case report

Benign fibrous histiocytoma (BFH) is a common mesenchymal lesion on the skin where it is better known as dermatofibroma. It mainly affects areas of the integument exposed to the sun. It can occur in the mucous membranes, being quite unusual in the oral cavity. This article presents a rare case of benign oral fibrous histiocytoma in childhood. An eleven-year-old male patient sought the stomatology clinic of the dentistry course at a reference university in northeastern Brazil, complaining of an asymptomatic increase in volume on the cheek, with an evolution of approximately two years. On intraoral examination, a lesion in the cheek mucosa was observed, measuring approximately 4 cm. The lesion had a nodular, circumscribed, reddish appearance, showing ulcerated areas covered by a yellowish pseudomembrane on its surface. The clinical diagnostic hypothesis was pleomorphic adenoma. Excisional biopsy was performed and, after morphological and immunohistochemical evaluation, the diagnosis of BFH was reached. Although it is a lesion with an excellent prognosis, BFH must be carefully analyzed for the differential diagnosis with malignant neoplasms that may have a mild appearance, such as fibrosarcoma or dermatofibrosarcoma. In addition, other benign lesions such as desmoplastic fibroblastoma, myofibroma, myopericytoma and nodular fasciitis may, in some histological sections, mimic the microscopic appearance of benign fibrous histiocytoma. In this reported case, immunohistochemical evaluation was essential to conclude the diagnosis of BFH(AU)

Benign fibrous histiocytoma of the tongue: a case report / Histiocitoma fibroso benigno em língua: relato de caso

The fibrous histiocytoma is a soft tissue neoplasm that affects the dermis and the subcutaneous tissue, rarely is found in the oral cavity and perioral regions, and is originated from the proliferation of fibroblasts and histiocytes. The objective of this paper is to report a case of Benign Fibrous Histiocytoma in a 30-year-old male patient, complaining of a painless nodule in the tongue for about six months. With diagnostic clinical hypotheses of Fibrous Hyperplasia, Neurofibroma, Traumatic Neuroma, Fibrous Histiocytoma, Granular Cell Tumor or Ectomesenchymal Chondromyxoid Tumor a excisional biopsy was performed. The histopathological examination revealed a non-encapsulated proliferation of spindle cells with some giant multinucleated cells in the periphery of the lesion. Immunohistochemical reactions were performed, staining only for vimentin in the spindle cells and for CD68 in the multinucleated giant cells. According to these characteristics, the final diagnosis was Benign Fibrous Histiocytoma. The correct diagnosis of spindle shaped cell neoplasia must be performed with the aid of histopathological analysis and immunohistochemistry, mainly because the morphological similarities with other benign and malignant lesions. (AU)

O Histiocitoma Fibroso é uma neoplasia de partes moles que acomete a derme e o tecido subcutâneo, raramente é encontrado na cavidade oral e regiões periorais, e tem origem a partir da proliferação de fibroblastos ou histiócitos. O objetivo deste artigo é relatar um caso de Histiocitoma Fibroso Benigno em um paciente masculino, 30 anos de idade, com um nódulo indolor, bem delimitado, com duração de cerca de seis meses, localizado no dorso anterior da língua. Com as hipóteses clínicas diagnósticas de Hiperplasia Fibrosa, Neurofibroma, Neuroma Traumático, Histiocitoma Fibroso, Tumor de Células Granulares e Tumor Condromixoide Ectomesenquimal uma biópsia foi realizada sob anestesia local e a lesão foi fixada em formol a 10% e enviada para análise histopatológica. O exame histopatológico revelou uma proliferação não-encapsulada de células fusiformes com algumas células gigantes multinucleadas na periferia da lesão. A marcação imunohistoquímica foi positiva para CD68 nas células gigantes multinucleadas e para vimentina nas células fusiformes. O diagnóstico final foi de Histiocitoma Fibroso Benigno. Para um diagnóstico correto, este deve ser feito correlacionando características clínicas, análise histopatológica e imunohistoquímica devido à similaridade microscópica do Histiocitoma Fibroso com outras lesões com aspecto fusocelular, assim como similaridade clínica com outras lesões benignas e malignas.(AU)