Parathyroid Carcinoma-An Experience of the Enigma Over 10 Years

Parathyroid carcinoma (PC) is an uncommon clinical entity. Identification and appropriate treatment of PC remains a challenge. In this study, we explore clinico-radiological features suggestive of PC, the utility of Castleman's histopathological criteria for the diagnosis of PC and discuss the MD-Anderson prognostic stratification system for PC.

Retrospective analysis (case series) of patients who were treated at our tertiary oncology institution between January 2009 and December 2018 with an eventual diagnosis of PC.

The study group comprised 15 patients. The most common presentation was related to the musculoskeletal system (n = 9, 60%). In one of the cases, ultrasound features were recorded to be suspicious of PC. The highest histopathological correlation with PC was found with capsular and vascular invasion (n = 12, 80%). The primary tumor was found in inferior parathyroid glands in most cases (n = 12, 80%). The average tumor size was 2.47 cm. Six patients (40%) received adjuvant radiotherapy (RT). Three patients (20%) developed recurrence, all having distant metastasis. Overall survival (OS) at 3 years was 92.31% and disease-free survival (DFS) of 76.61%.

The presence of certain features on ultrasonography might suggest PC preoperatively. Among Castleman's criteria, capsular invasion and vascular invasion had a maximum association with PC in our series. At present, there is no evidence to routinely give adjuvant RT to all patients with PC.