# Benign giant pilomatricoma with associated hypercalcemia: a case report

## TL;DR

A patient with a large benign tumor on her shoulder also had high blood calcium levels, which normalized after the tumor was removed.

## Contribution

This case report highlights that benign pilomatricomas can rarely cause hypercalcemia by secreting PTHrP.

## Key findings

- Surgical resection of the pilomatricoma normalized the patient's calcium and PTHrP levels.
- The tumor was associated with hypercalcemia and elevated parathyroid hormone-related peptide (PTHrP) levels.

## Abstract

The patient presented to the emergency department with nausea and vomiting with a large, rapidly growing soft tissue mass on her left shoulder diagnosed as a giant pilomatricoma. Pilomatricomas are tumours derived from hair follicles that are typically benign and rarely cause systemic symptoms. However, this patient exhibited hypercalcemia and elevated parathyroid hormone-related peptide (PTHrP) levels, suggesting PTHrP secretion by the tumour. Surgical resection normalized the patient's calcium and PTHrP levels. This case demonstrates that tumours such as pilomatricomas can rarely secrete PTHrP and cause hypercalcemia, a characteristic not typically associated with benign growths. It emphasizes the importance of considering benign tumours in the differential diagnosis of hypercalcemia.