Pathology data set for reporting parathyroid carcinoma and atypical parathyroid neoplasm: recommendations from the International Collaboration on Cancer Reporting

Standardized pathologic reporting for cancers improves patient care and prognostic determination. However, access in many countries is limited. To address this issue, the International Collaboration on Cancer Reporting (ICCR), a not-for-profit organization, has the mission to develop and disseminate standardized data sets for global use. Within endocrine organs, the parathyroid gland has rarely been included in formal pathologic data sets. Utilizing an expert international panel of eleven members, an evidence-based data set was developed for parathyroid carcinoma and atypical parathyroid neoplasms. This data set consists of sixteen core (required) elements viewed as essential for documentation of these conditions. Characterizing parathyroid carcinomas and atypical neoplasms begins with correlative clinical information, the operative procedure, specimens submitted, and site of the disease. The pathologic features essential to document include parathyroid weight, size, classification, and, when a carcinoma, the tumor grade. Histologic grade of parathyroid carcinoma incorporates other core elements including necrosis, mitotic count, perineural invasion, and lymphovascular invasion. Documenting the extent of disease locally into adjacent organs, regionally, and distally is critical for staging. Pathologic staging is now included as part of the American Joint Committee on Cancer 8th edition and is included in this data set. Ancillary studies should be recorded when performed as noncore elements. Standardized pathologic data sets for endocrine organs including the parathyroid gland are now available through the ICCR website. These essential resources enhance international standardization for documenting these rare tumors for both patient care and future guidelines.