Histological alterations following fine‐needle aspiration for parathyroid adenoma: Incidence and diagnostic problems

Abstract

This study aimed to clarify the histological alterations following fine‐needle aspiration for parathyroid adenoma and discuss the occurrence of diagnostic problems. Among the 392 patients with parathyroid adenoma who underwent resection, fine‐needle aspiration was performed for 21 (5.1%) parathyroid adenoma nodules. Histological findings that were significantly more frequent in cases that underwent fine‐needle aspiration were considered histological alterations following fine‐needle aspiration for parathyroid adenoma, including the following six findings: thick fibrous capsule (71.4%), multilayered fibrous capsules (14.3%), capsular pseudo‐invasion (42.9%), fibrous bands (57.1%), hemosiderin deposition (14.3%), and tumor implantation (14.3%). Eighteen parathyroid adenoma nodules (85.7%) exhibited one or more of the six findings. Tumor cells and adipocytes entrapped within the thick fibrous capsule were occasionally observed. The fibrous bands were frequently connected to the thick fibrous capsule. The number of passes, duration between fine‐needle aspiration and resection, tumor size, and purpose of fine‐needle aspiration were not related to the incidence of histological findings. Because of the histological alterations following fine‐needle aspiration for parathyroid adenoma that can be easily mistaken for signs of atypical adenoma or parathyroid carcinoma, we recommend that the six findings be excluded from pathological findings indicating atypical adenoma or parathyroid carcinoma in patients with preoperative fine‐needle aspiration.

Fine needle aspiration biopsy of parathyroid; is it meaningful? A cytologic study of 81 cases with histological and clinical correlations

“…41 Potential complications of FNA includes hematoma, parathyroid abscess, disruption of the lesion and seeding along the needle tract (parathyromatosis) or dense fibrotic reaction to the needle. [57][58][59][60][61] These uncommon events may rarely convert a minimally invasive surgery to a standard surgical approach. 62 In the majority of reported series of parathyroid FNA no severe complication occurred and in the present study, there were no reported complications associated with FNA of parathyroid gland.…”

“…Potential complications of FNA includes hematoma, parathyroid abscess, disruption of the lesion and seeding along the needle tract (parathyromatosis) or dense fibrotic reaction to the needle 57–61 . These uncommon events may rarely convert a minimally invasive surgery to a standard surgical approach 62 .…”

Advances and Updates in Parathyroid Pathology

“…While these features should raise the suspicion of malignancy, these histologic features alone are not diagnostic as they can be seen in both PA and parathyroid hyperplasia making the diagnosis of PC challenging 6,11,40,41. In particular, fibrosis can be seen post–fine-needle aspiration (FNA), after therapeutic ethanol injection, in the setting of secondary/tertiary HPT, and in large, degenerated adenomas 42–44. When areas of fibrosis are identified, a careful search for prior manipulations such as FNA should be performed.…”

“…6,11,40,41 In particular, fibrosis can be seen post-fine-needle aspiration (FNA), after therapeutic ethanol injection, in the setting of secondary/tertiary HPT, and in large, degenerated adenomas. [42][43][44] When areas of fibrosis are identified, a careful search for prior manipulations such as FNA should be performed. Knowledge of the history of chronic renal failure and secondary or tertiary HPT is also useful.…”