Pigmented neurofibroma with hypertrichosis / Neurofibroma pigmentado con hipertricosis

Abstract Background: Pigmented (or melanocytic) neurofibroma (PN) constitutes only 1% of cases and is considered a rare variant of neurofibroma containing melanin-producing cells. In addition, the association of PN with hypertrichosis is infrequent. Case report: We describe the case of an 8-year-old male with a neurofibromatosis type 1 (NF1) diagnosis, who presented a light brown hyperpigmented plaque, smooth and well-demarcated, and hypertrichosis on the left thigh. The skin biopsy showed characteristics of neurofibroma; however, in the deep portion of the lesion, melanin deposits positive for S100, Melan-A, and HMB45 were observed, thus establishing the diagnosis of pigmented neurofibroma. Conclusions: Although PN is a rare subtype of neurofibroma, it is considered a chronically progressive benign tumor containing melanin-producing cells. These lesions can appear alone or in association with neurofibromatosis. Since this is a tumor that can be confused with other skin lesions, biopsy analysis is essential to differentiate it from other pigmented skin tumors, such as melanocytic schwannoma, dermatofibrosarcoma protuberans, neurocristic hamartoma, or neuronevus. Surveillance is part of the treatment, and surgical resection is sometimes performed.

Resumen Introducción: El neurofibroma pigmentado (NP) o melanocítico constituye solamente el 1% de los casos y se considera como una variante rara del neurofibroma que contiene células productoras de melanina. Además, la asociación de NP con hipertricosis es muy rara. Caso clínico: Se describe el caso de un paciente de sexo masculino de 8 años 2 meses de edad con diagnóstico de neurofibromatosis tipo 1 (NF1), quien presentaba en la cara anterior del muslo izquierdo una placa hiperpigmentada de color café claro, bien delimitada y de consistencia suave, e hipertricosis. La biopsia de piel presentó cambios característicos de neurofibroma; sin embargo, en la porción profunda de la lesión se observaron depósitos de melanina positivos para S100, Melan-A y HMB45, con lo que se estableció el diagnóstico de neurofibroma pigmentado. Conclusiones: Aunque el NP es un subtipo raro del neurofibroma, se considera que es un tumor benigno de evolución crónica de células productoras de melanina. Estas lesiones aparecen en solitario o asociadas con neurofibromatosis. Dado que es un tumor que puede confundirse con otras lesiones cutáneas, es fundamental el análisis de la biopsia para diferenciarlo de otros tumores cutáneos pigmentados, como el schwanoma melanocítico, dermatofibrosarcoma protuberans, hamartoma neurocrístico o neuronevus. La vigilancia es parte del tratamiento y, en ocasiones, se lleva a cabo la resección quirúrgica.

A Case of a Pigmented Neurofibroma Resembling a Giant Congenital Melanocytic Nevus / 대한피부과학회지

In the spectrum of neurofibroma, pigmented neurofibroma is a rare variant observed in patients with or without neurofibromatosis. It is histologically characterized by the presence of scattered melanin-laden pigmented cells within the neurofibromatous lesion. Herein, we describe a case of a 30-year-old man who presented with a large pigmented patch showing focal hypertrichosis on the upper back. The lesion had been present at birth and there was no other cutaneous features to support a diagnosis of neurofibromatosis. Histologically, a proliferation of melanocytes was evident in the epidermis and upper dermis and within underlying neurofibromatous tissue. This abnormality resulted in diagnostic difficulty in the differentiation between pigmented neurofibroma and large congenital melanocytic nevus with complete neurotization because of the clinical and histological similarities. In support of the use of immunohistochemical markers, the diagnosis of pigmented neurofibroma could be made.

A Case of Pigmented Neurofibroma Associated with Giant Cafe-au-lait Patches / 대한피부과학회지

Pigmented neurofibroma is a rare cutaneous tumor accounting for less than 1% of all neurofibroma. It is characterized histologically by the coexistence of scattered melanin-laden cells and benign spindle cells with neural differentiation. The origin of these tumors are unknown, and they show a storifom pattern. In our case, the patient had giant cafe au lait patches on the left trunk which had been present since birth, freckles on both axilla, and two dark-red colored plaques which had appeared 2 years ago. Histologic examination revealed pigmented neurofibromas showing the melanin-laden, pigmented cells within the upper dermis and plexiform neurofibromas in the subcutaneous tissue. We describe a case of pigmented neurofbroma in a 13-year-old male patient.

A Case of Neurofibromatosis with Giant Pigmentation, Diffuse Neurofibromas and a Pigmented Neurofibroma / 대한피부과학회지

A 31-year-old man presented with an erythematous tumor within a giant pigmentation on the left arm, which was partially covered with hairs and had a few subcutaneous nodules within it. Also he had a bluish tumor on the left palm, multiple tumors and cafe au lait spots on the upper trunk. Histologic examination from the tumor, pigmentation and subcutaneous nodules on the left arm, and the tumors on the upper trunk and left palm all revealed neurofibromas. Interestingly, the rare types of the neurofibromas, diffuse and pigmented neurofibroma were included in these.

A Case of Pigmented Neurofibroma

Pigmented neurofibroma, a variant of neurofibroma, has rarely been observed in patients with or without neurofibromatosis. Pigmented neurofibroma is characterized histologically by the coexistence of scattered melanin-laden cells and benign spindle cells with neural differentiation. We report a case of pigmented neurofibroma in a 22-year-old female patient.

A Case of Primary Neurofibroma of Lacrimal Sac

Lacrimal sac tumors are relatively rare and epithelial origin, mostly. The clinical menifestations of lacrimal sac tumors include epiphora, chronic dacrtocystitis, or lacrimal mass. Primary neurofibroma of lacrimal sac is benign nature and malignant transformation is rare. But malignant lacrimal sac tumors can be life-threatening; Therefore, the early diagnosis and treatment are important. We reported an experience of a 37-year-old female who had epiphora, pruritis, lacrimal mass, and facial asymmetry. The patient was finally diagnosed with pigmented neurofibroma of lacrimal sac that was proven by dacryocystogram, CT scan, and histophthologic finding.

A Case of Melanotic Neurofibroma Associated with Skull Defect in Neurofibromatosis

An unusual case of melanotic neurofibroma which involves subcutaneous tissue and dura in the occipital area is presented. The physical examination showed cutaneous pigmentation(cafe au lait spots) and multiple cutaneous tumors(fibroma molluscum). Magnetic resonance imaging showed plexiform neurofibroma and dural ectasia of typical finding of neurofibromatosis. The patient underwent surgical removal of the tumor as well as cranioplasty of the skull defect. The authors reviewed the literatures and discussed the pathogenesis of this extremely rare case.