# Pulmonary ossification: a case report

## TL;DR

This case report describes a rare instance of lung ossification linked to a mild form of hyperparathyroidism with normal calcium levels.

## Contribution

The novelty lies in the rare association of dendriform pulmonary ossification with normocalcemic subclinical primary hyperparathyroidism.

## Key findings

- The patient exhibited dendriform ossification in the lungs.
- Subclinical primary hyperparathyroidism was identified alongside normal serum calcium levels.
- Diffuse calcifications were observed in conjunction with the lung ossification.

## Abstract

Pulmonary calcification and ossification are uncommon findings characterized by the deposition of calcium salts or bone tissue in the lung, generally associated with chronic kidney disease, hyperparathyroidism, and several other causes (1). Ossification is bone formation without or with marrow elements in the lung (1). In some patients, a new entity of subclinical primary hyperparathyroidism has been detected, characterized by persistently elevated parathyroid hormone concentration and normal serum calcium level, usually asymptomatic (2). CT scan is the standard method for detecting calcification and ossification. Radiological presentation on CT is characterized by round or lobulated nodules (3). Follow-up consists of monitoring lung images and lung function to assess disease progression. It suggests an annual CT scan. In this case, we presented a rare association of dendriform ossification with normocalcemic hyperparathyroidism, in particular, in a patient with pulmonary ossification, subclinical primary hyperparathyroidism, and diffuse calcifications.