# Pulmonary osseous metaplasia in association with renal cell carcinoma: A rare case report and literature review

## TL;DR

A rare case of lung bone tissue formation linked to kidney cancer is reported, highlighting its unusual nature and diagnostic challenges.

## Contribution

This case report adds to the limited understanding of pulmonary osseous metaplasia associated with renal cell carcinoma.

## Key findings

- Pulmonary osseous metaplasia was confirmed in a patient with renal cell carcinoma via histopathological examination.
- The condition was identified during surgery for a suspected metastatic lung nodule.
- The exact cause of POM remains unclear, but chronic inflammation is a possible factor.

## Abstract

Pulmonary osseous metaplasia (POM) is a rare occurrence often discovered postmortem, involves the development of fully formed bone tissue within the lung parenchyma. The aim of this study is to present a case of pulmonary osseous metaplasia in a 66-year-old female. A 66-year-old woman previously diagnosed with renal cell carcinoma (RCC) was referred for a pulmonary nodule discovered during a CT scan due to chest pain and shortness of breath. Clinical exams were normal, and the CT revealed solid nodules suspected to be metastatic. The patient underwent uniport video-assisted thoracoscopic surgery (VATS) for nodule resection, revealing metastatic disease and myeloid-osseous metaplasia in histopathological examination. After a 4-day hospital stay with intravenous antibiotics, the postoperative period was uneventful. The exact etiology of POM remains unclear, but it is thought to be associated with chronic inflammation and irritation of the lung tissue. The diagnosis of POM typically requires histopathological confirmation, and treatment options are limited due to its rarity. Myeloid osseous metaplasia of the lung is an exceedingly rare occurrence, and it may be associated with renal cell carcinoma.

Image, graphical abstract