Schwannoma of the penis, presenting as a scrotal mass, rare entity with an uncommon presentation

Multiple Penile and Scrotal Schwannomas in an Adult Patient: A Case Report

INTRODUCTION

Schwannomas originate from the peripheral nerve sheaths and are mainly detected in the head, neck, or extremities. They are rarely encountered in the penoscrotal region.

CASE PRESENTATION

Herein, we present a case of a penoscrotal schwannoma diagnosed and successfully treated in our center. A 40-year-old patient with a history of resection of a dorsal penile schwannoma presented with multiple nodular lesions at the scrotum, penile shaft, and radix, which were first noticed 5 years before his current presentation. He complained about penile pain and dyspareunia. Magnetic resonance imaging was performed for preoperative diagnosis. All nodular lesions were resected while preserving the neurovascular structures. The histopathological examination revealed benign lesions. The patient's complaints were resolved, and there was no recurrence during the 1-year follow-up.

CONCLUSION

The primary treatment is surgical excision. The patients need close follow-up regarding the risks of recurrence and malignant transformation.

Penile schwannoma mistaken for hemangioma: a rare case report and literature review

Penile neoplasm is uncommon. Schwannomas of the penis are especially rare. For this reason, it is difficult to get an accurate impression to enable decision making. This report primarily deals with the mistaken diagnosis of hemangioma, to the surgery, and the follow-up in real-world. A 38-year-old male patient presented with a palpable mass in the penile root that increased in size with erection. One year after the mass had been found, the patient visited the hospital and complained that the mass was growing. Moreover, the patient explained that the mass seemed to increase during penile erection. On physical examinations, a 2 cm mass without tenderness was palpated in the left penoscrotal junction. About 2.1 cm in size, an isoechoic mass was observed next to the corpus cavernosum on ultrasonography. There was high vascularity inside of the mass. Excision and biopsy were decided upon. Following surgery, a schwannoma was confirmed by pathology. After three months, the patient did not complain of any symptoms and had normal erectile function. Most of these tumors are benign. By December 2020, 40 cases were reported, of which 6 were diagnosed as malignant. The most frequent occurrence site is the penile shaft. In all cases, surgical resection was performed and no recurrence was found. The aim of this case report is to assist clinicians in choosing the best treatment option when faced with this rare condition by discussing the radiological, pathological, and clinical course.

Clinicopathological Presentation and Management of Penile Schwannoma

INTRODUCTION

Patients with penile schwannoma are rare and usually with variant presentations. No evidence-based clinical guideline exists for diagnosis or treatment. To put schwannoma into differential diagnoses of benign soft tissue lesions in the penis is important.

AIM

To analyze and categorize clinical, histopathological, and radiological presentations and apply possible explanation on several fields of penile schwannoma.

METHODS

We collected the English literature through the PubMed database of the National Library of Medicine up to October 2019. A newly diagnosed case in Chang Gung Memorial Hospital, Taiwan, was also included. This study categorized lesion locations into the penile body or shaft, glans, or penile root, dorsal or ventral.

MAIN OUTCOME MEASURE

The main outcome measure was to demonstrate clinical, pathological, ultrasonography, and MRI manifestations of penile schwannoma and perform immunohistochemistry staining that has not been performed among penile schwannomas.

RESULTS

We collected 40 cases. Data were arranged in tables. Clear descriptions were added on several fields of penile schwannoma in detail in Discussion.

CONCLUSION

Penile schwannomas are mostly located at the penile shaft and dorsum of the penis. Dyspareunia is the most reported complaint for sexual dysfunction. This study is the first study in the world to document the expressions of calretinin, SOX10, glial fibrillary acid protein, D2-40 (podoplanin), and cytokeratin AE1/AE3 in penile schwannoma and claims magnetic resonance imaging and pathologic presentations of penile schwannomas are synonymous with schwannomas from head to toe. The current patient may be the first to present with penile schwannoma with schwannomatosis. Huang LC, Wang HZ, Chu YC, et al. Clinicopathological Presentation and Management of Penile Schwannoma. Sex Med Rev 2020;8:615-621.

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

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.