Rare case of parathyroid gland sarcoidosis presenting with hypercalcaemia

Abstract

Sarcoidosis of the parathyroid gland is a rare occurrence. Parathyroid sarcoidosis is usually associated with parathyroid adenomas, and, therefore, hypercalcaemia is a common presentation of this entity. We present a case of parathyroid sarcoidosis and review the world literature regarding this rare condition. A woman with a history of diffuse large B cell lymphoma underwent a surveillance positron emission tomography scan that showed increased fluorodeoxyglucose uptake in multiple thoracic and abdominal lymph nodes and in a left upper extremity soft tissue mass. Biopsy of the soft tissue mass showed non-caseating granulomas consistent with sarcoidosis. Blood work showed a serum calcium of 11.1 mg/dL with an intact serum parathyroid hormone of 92 pg/dL. Primary hyperparathyroidism was suspected. A neck ultrasound and sestamibi parathyroid scintigraphy demonstrated a parathyroid nodule. She underwent surgical resection, and the histopathology revealed a parathyroid adenoma and non-caseating granulomata consistent with a diagnosis of sarcoidosis.

Keywords: calcium and bone; ear, nose and throat/otolaryngology; endocrine system; respiratory system.

Figure 1

Sarcoidosis involving the soft tissue. (A) Soft tissue (H&E stain, 40×) with a confluent nodular mass aggregate of multiple discrete non-caseating granulomas consistent with sarcoidosis (black arrows). The granulomas are bridged by dense eosinophilic hyaline fibrosis with intermixed chronic inflammation. (B) High-power image of soft tissue granuloma (200×) showing a discrete micronodular aggregate of epithelioid histiocytes with multinucleated giant cells (yellow arrow) and sparse admixed lymphocytes cuffed by dense laminated eosinophilic hyaline fibrosis. Acid-fast and Grocott-Gomori’s methamine silver stains were negative for mycobacterial and fungal organisms.

Figure 2

Granulomatous involvement of the parathyroid gland in a sarcoidosis patient with a parathyroid adenoma. (A) Hypercellular parathyroid, consistent with parathyroid adenoma (40×), with a nodular aggregate of discrete non-necrotising granulomas (black arrows) bridged by dense hyaline fibrosis. (B) High-power image of parathyroid granuloma (200×) showing a discrete micronodular aggregate of epithelioid histiocytes with admixed multinucleated giant cells (yellow arrows) and admixed lymphocytes.