Plexiform Schwannoma of the Penis: A Rare Subtype of Genital Schwannoma

Abstract

Schwannomas are benign, encapsulated neurogenic tumors which present in diverse histological subtypes despite the limited variety of their cellular constituents. These include the cellular, ancient, cystic, epithelioid, melanotic, psammomatous, schwannoma with pseudoglandular elements, and plexiform varieties. The plexiform schwannoma (PS) represents 4.3% of all schwannomas. These lesions are commonly encountered in the head and neck region and are extremely rare in the penis. To the best of our knowledge only 34 cases of penile schwannomas have been reported and this is the 3rd case of plexiform penile schwannoma. A 39-year-old patient presented to our andrology outpatient clinic complaining for two painful penile nodules. The lesions were located on the dorsum of the penile shaft. His medical history was insignificant for penile trauma and sexual transmitted diseases. The masses measured 2x1 cm and 0.5x1 cm. After sonographic and magnetic resonance evaluation the patient was admitted to theatre and underwent topical resection of the lesions. Histopathology revealed plexiform schwannoma. Postoperatively, penile tenderness and hyperesthesia ensued which was managed with pregabalin administration and topical corticosteroids. Plexiform schwannomas are rare in the penile region. Surgical excision is inevitably the only way to diagnose and treat the lesions. They must be differentiated by a variety of malignant and benign clinical conditions. Topical excision suffices for oncological control and allows for acceptable functional outcomes.

Schwannoma of the dorsal nerve of the penis: case report and differential diagnoses

“…These tumors are frequent in extremities, face or head. Despite the great innervation of the penis, the presence of these tumors constitutes an atypical manifestation with < 200 cases reported in the literature since its first description in 1968 [1][2][3][4] . The average age of appearance is usually 39 years 1 .…”

“…They are encapsulated tumors of which different histological subtypes have been described based on the cells that compose them, the main ones being cystic, epithelioid, melanocytic, with psammoma bodies, and plexiform 3 .…”

“…Despite the great innervation of the penis, the presence of these tumors constitutes an atypical manifestation with < 200 cases reported in the literature since its first description in 1968 [1][2][3][4] .…”

Robot-Assisted Nerve-Sparing Excision of a Symptomatic Obturator Nerve Schwannoma: A Case Report

“…Schwannomas are benign lesions that derive from Schwann cells, which are the cells responsible for the production of the protective myelin sheath that covers peripheral nerves. These lesions include the cellular, ancient, cystic, epithelioid, melanotic, psammomatous, schwannoma with pseudoglandular elements, and plexiform varieties [1]. Like most benign tumors, they present a relatively slow growth rate and a noninvasive character.…”

Visceral plexiform schwannoma: A case series

“…PS is typically characterised by a benign course, but it may be associated with neurofibromatosis (NF) and the differential diagnosis from its malignant counterparts (e.g., neurofibroma and malignant peripheral nerve sheath tumour) may be difficult (6). The aim of the present study was to retrospectively describe two unique cases of PS with a visceral location in young children, as well as one case that has been previously reported by one of the authors, in order to highlight the importance of considering this entity in the differential diagnosis of abdominal masses and to perform a careful investigation of associated abnormalities, particularly NF.…”