A Rare Case of Schwannoma at the Glans Penis: Comprehensive Clinical and Radiological Evaluation, Surgical Management, and Long-Term Follow-Up

TL;DR

A rare case of a benign tumor called schwannoma at the tip of the penis is reported, with detailed clinical, radiological, and surgical findings, and a successful long-term outcome.

Contribution

This paper presents a rare clinical case of schwannoma at the glans penis with comprehensive evaluation and long-term follow-up.

Findings

MRI was effective in delineating the tumor's characteristics and surgical planes.

Histopathology and immunohistochemistry confirmed the diagnosis of schwannoma.

The patient remained asymptomatic with no recurrence after four years of follow-up.

Abstract

Schwannomas (also known as neurilemmomas) are benign peripheral nerve sheath tumors that arise from Schwann cells. Although they can occur throughout the body, penile involvement is exceedingly rare. Among these, schwannomas of the glans penis are exceptionally uncommon. Their nonspecific presentation often poses a diagnostic challenge, making accurate preoperative identification difficult.

We report the case of a sexually active 33-year-old man who presented with a painless, slowly enlarging mass on the dorsal aspect of the glans penis. Physical examination revealed a solitary, well-circumscribed, soft to firm, non-tender nodule measuring approximately 2 × 2 cm, without overlying skin changes or regional lymphadenopathy. Ultrasonography demonstrated a hypoechoic lesion with internal septations and vascularity. Contrast-enhanced multiplanar MRI of the penis showed a 2.1 × 1.7 × 1.7 cm well-circumscribed, avidly enhancing soft-tissue mass with internal cystic/necrotic areas, abutting but not invading the urethra or terminal penile musculature. Surgical excision was performed through a vertical glans incision.

Intraoperatively, an encapsulated mass was carefully dissected from surrounding adhesions and excised completely. Frozen section analysis showed no malignant cells. Histopathological examination revealed a spindle cell neoplasm with Antoni A and Antoni B areas, nuclear palisading, myxoid stromal change, collagenization, and sclerosis, with no mitotic activity or atypia. Immunohistochemistry demonstrated strong, diffuse S-100 positivity, consistent with a conventional schwannoma.

The patient was reviewed clinically at three months, six months, and annually thereafter. At the four-year follow-up, he remained asymptomatic, with preserved erectile and urinary function and no evidence of recurrence or penile deformity.

Penile schwannomas are rare benign tumors with an excellent prognosis after complete excision. Preoperative diagnosis is often limited by nonspecific clinical and imaging findings; however, MRI contributes significantly by delineating lesion characteristics and surgical planes. Histopathology with immunohistochemistry remains essential for definitive diagnosis. Recurrence, though uncommon, has been reported; hence, long-term follow-up is advisable. Even in rare locations such as the glans, schwannoma should be considered in the differential diagnosis of penile masses.

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