Avoiding overdiagnosis of parathyroid carcinoma

Area of Science:

• Surgical pathology
• Oncology
• Endocrinology

Background:

• Parathyroid carcinoma diagnosis relies on identifying invasive growth, a key malignancy indicator.
• Distinguishing invasive features from artifacts and mimics is crucial for accurate staging (e.g., pT1 vs. pT2).
• Mimics include post-biopsy changes, crush artifacts, peliosis, and displaced tumor cells, complicating diagnosis.

Purpose of the Study:

• To review diagnostic challenges in parathyroid carcinoma, focusing on invasive growth criteria and mimics.
• To highlight pitfalls that can lead to overdiagnosis of parathyroid carcinoma.
• To emphasize the importance of a consolidated diagnostic workup for parathyroid tumors.

Main Methods:

• Review of histological criteria for parathyroid carcinoma invasion.
• Discussion of common artifacts and mimics simulating malignancy.
• Integration of clinical, histological, immunohistochemical, and molecular features.

Main Results:

• Invasive growth includes angioinvasion, lymphatic, perineural invasion, and direct invasion into adjacent structures.
• Artifacts like fibrosis, crush, and peliosis can mimic invasion.
• Intrathyroidal location and parathyromatosis present additional diagnostic complexities.

Conclusions:

• Accurate diagnosis of parathyroid carcinoma requires meticulous evaluation to differentiate true invasion from artifacts.
• A multi-faceted approach combining multiple tissue levels and biomarkers is essential.
• Awareness of potential diagnostic pitfalls is critical for pathologists to avoid overdiagnosis.