# Penile Osteosarcoma: A Rare Extraosseous Site

## TL;DR

A rare case of penile osteosarcoma is reported, highlighting its diagnosis and treatment through surgery and lymph node dissection.

## Contribution

This paper presents a new clinical case of primary penile extraosseous osteosarcoma, adding to the limited existing literature on this rare condition.

## Key findings

- The patient had a high-grade sarcoma with osteoid production, diagnosed via histology after partial penectomy.
- Lymph node dissection revealed no malignancy in examined nodes, and the patient showed no recurrence at five months post-surgery.

## Abstract

Primary penile extraosseous osteosarcoma (EOS) ranks the most uncommon amongst the differential penile masses, with only nine cases reported so far. In this report, we share the management of a 67-year-old Hispanic male who presented with a painful mass over his distal penile shaft and glans for the last two months. After initial imaging and complete blood investigations, he underwent partial penectomy. Histology revealed high-grade sarcoma, with osteoid production, favoring high-grade extra-skeletal osteosarcoma, with tumor necrosis involving approximately 5% of the tumor volume. The patient had bilateral palpable inguinal lymphadenopathy, which was seen even on a pre-op CT scan. The patient thus underwent bilateral robotic superficial and deep inguinal standard template lymph node dissection three weeks after his partial penectomy. His pathology was negative for malignancy in all examined lymph nodes. At his last follow-up, five months post his primary surgery, he had been doing well without concerns for recurrence.