Parathyroid carcinoma (PC) is an extremely rare malignant endocrine tumour of the parathyroid glands. Due to its rarity, several aspects regarding diagnosis, prognosis, clinical management, recurrence, and tumour-related complications remain poorly understood. The absence of standardized diagnostic and treatment protocols highlights the need for international collaboration and systematic data collection through dedicated registries.

To describe the design and development of a dedicated European registry module for parathyroid carcinoma cases within the European Registries for Rare Endocrine Conditions (EuRRECa), aiming to improve knowledge of disease characteristics, clinical management, outcomes, and long-term complications.

A dedicated parathyroid carcinoma working group within EuRRECa developed a condition-specific registry module for the collection of clinical data from patients with parathyroid carcinoma. The module was designed to capture information on patient characteristics, diagnosis, treatment strategies, disease progression, complications, and outcomes. Data collection is performed through the electronic reporting system (e-REC), accessible to registered healthcare professionals participating in the registry.

The parathyroid carcinoma module was developed within the EuRRECa framework and launched at the end of 2022. The registry provides a structured platform for collecting standardized data on parathyroid carcinoma cases across Europe, enabling the aggregation of cases from multiple expert centres. The collected data aim to support the identification of factors influencing diagnosis, natural disease course, prognosis, skeletal complications, and treatment approaches.

The EuRRECa parathyroid carcinoma module represents an important step towards improving knowledge of this extremely rare endocrine malignancy. International registry-based collaboration will facilitate the collection of larger datasets, support clinical research, and may contribute to the development of evidence-based approaches for diagnosis, treatment, and follow-up of patients with parathyroid carcinoma.

Parathyroid carcinoma is one of the rarest endocrine malignancies, resulting in limited evidence regarding optimal diagnosis, treatment, and follow-up. The EuRRECa parathyroid carcinoma registry provides a European platform for systematic data collection and collaboration between expert centres, creating opportunities to better understand disease outcomes and improve patient care.