Contemporary Management of Primary Hyperparathyroidism

Quality appraisal of clinical practice guidelines for the evaluation and management of primary hyperparathyroidism

PURPOSE

Multiple groups have created clinical practice guidelines (CPGs) for the management of primary hyperparathyroidism (PHPT). This report provides a rigorous quality assessment using the Appraisal of Guidelines for Research & Evaluation Instrument (AGREE II) to identify high-performing guidelines and areas for improvement.

METHODS

A systematic review was conducted to isolate CPGs addressing the management of PHPT. Guideline data was extracted and quality ratings were assigned by four independent reviewers. Intraclass correlation coefficients (ICC) were calculated to ensure interrater reliability.

RESULTS

Twelve guidelines were assessed. The American Association of Endocrine Surgeons (AAES) guideline had the highest mean scaled score across all domains (73.6 ± 31.4%). No other published guideline achieved a "high" quality designation. The highest scoring domain was "clarity of presentation" (mean 60.5 ± 26.5%). The lowest scoring domain was "applicability" (mean 19.8 ± 18.2%). Scoring reliability was excellent, with ICC ≥ 0.89 for all AGREE II 6 domains.

CONCLUSION

Although several working groups have developed guidelines to address PHPT management, only those published by the AAES meet all methodologic quality criteria necessary to ensure incorporation of recommendations into clinical practice. Future guidelines would benefit from the development of tools, resources, monitoring criteria that enhance applicability.

Immunohistochemical Profile of Parathyroid Tumours: A Comprehensive Review

Immunohistochemistry remains an indispensable tool in diagnostic surgical pathology. In parathyroid tumours, it has four main applications: to detect (1) loss of parafibromin; (2) other manifestations of an aberrant immunophenotype hinting towards carcinoma; (3) histogenesis of a neck mass and (4) pathogenetic events, including features of tumour microenvironment and immune landscape. Parafibromin stain is mandatory to identify the new entity of parafibromin-deficient parathyroid neoplasm, defined in the WHO classification (2022). Loss of parafibromin indicates a greater probability of malignant course and should trigger the search for inherited or somatic CDC73 mutations. Aberrant immunophenotype is characterised by a set of markers that are lost (parafibromin), down-regulated (e.g., APC protein, p27 protein, calcium-sensing receptor) or up-regulated (e.g., proliferation activity by Ki-67 exceeding 5%) in parathyroid carcinoma compared to benign parathyroid disease. Aberrant immunophenotype is not the final proof of malignancy but should prompt the search for the definitive criteria for carcinoma. Histogenetic studies can be necessary for differential diagnosis between thyroid vs. parathyroid origin of cervical or intrathyroidal mass; detection of parathyroid hormone (PTH), chromogranin A, TTF-1, calcitonin or CD56 can be helpful. Finally, immunohistochemistry is useful in pathogenetic studies due to its ability to highlight both the presence and the tissue location of certain proteins. The main markers and challenges (technological variations, heterogeneity) are discussed here in the light of the current WHO classification (2022) of parathyroid tumours.