Type I neurofibromatosis with spindle cell sarcoma: A case report

Perineum Spindle Cell Sarcoma in Neurofibromatosis Type 1

Soft tissue neoplasm is common among patients with neurofibromatosis type 1 (NF-1). We present a case of a middle-aged woman with NF-1 who presented with a painless, insidiously increasing perineal mass for the past eight months. She underwent colonoscopy, computed tomography staging, magnetic resonance imaging of the pelvis, core-needle biopsy, and later wide local excision of left perineum swelling. Histopathological examination showed a high-grade spindle cell sarcoma, which is a rare association among NF-1. Spindle cell sarcoma is a group of malignant soft tissue tumors with locally destructive growth with spindle-shaped neoplastic cells. The solitary spindle cell sarcoma of the perineum is rare, and wide local resection with a clear margin is the only treatment at present-the scarcely available evidence limiting the use of adjuvant chemotherapy, immunotherapy, and radiotherapy.

Endoscopic finding of leiomyosarcoma in a neurofibromatosis patient

A man with a history of neurofibromatosis presented to our hospital with a soft palate mass. Since the patient had neurofibromatosis, we diagnosed the mass as a neurofibroma and planned annual regular follow-up without any treatment. Five months later, the patient visited our emergency department because of uncontrolled epistaxis, and the mass was enlarged to the extent of the airway obstruction. Endoscopic resection was performed and the tumor was confirmed to be a leiomyosarcoma. The malignant potential of the new lesion in a neurofibromatosis patient should be actively evaluated and treated, if required.

Primary Bone Leiomyosarcoma in Neurofibromatosis Type 1: Extremely Rare Concurrency

Neurofibromatosis type 1 (NF1) is a complex autosomal dominant, multisystem genetic disease affecting about 1 in 3500 individuals. Plexiform neurofibromas represent a rare variant (30%) of NF1 in which the spread of tumor cells along nerve fascicles leads to a diffuse mass of thickened nerve fibers. Affected patients with NF1 have a greater chance of developing soft tissue sarcomas than the general population. Leiomyosarcoma is one of the most frequent soft tissue sarcomas, seldom observed in patients with NF1. Herein we report a rare concurrency of bone leiomyosarcoma in a patient with a plexiform neurofibroma, adding to the few reported cases of leiomyosarcomas in patients with NF1. Our case is a 14-year-old male who is a known case of NF1 and presented with a four-month history of pain and swelling on the medial side of the right knee. Imaging and biopsy confirmed the diagnosis of leiomyosarcoma. Based on the authors' knowledge and search, this is the first reported case of plexiform neurofibroma with a primary bone leiomyosarcoma, representing an extremely rare concurrency. Patients with such uncommon tumors should be assessed regularly, and continuous follow-up is essential.