Oxyphilic Hypercellular Follicular Nodule (OHCFN) of the Thyroid: A 10 Year Experience
AL Patton, SP Gmitro, JA Brainard. Cleveland Clinic, Cleveland, OH
Background: The term oxyphilic hypercellular follicular nodule (OHCFN) is used in thyroid FNA to describe cellular aspirate samples comprised nearly exclusively of Hurthle cells. Associated surgical pathology diagnoses commonly include benign hyperplastic nodule in the setting of lymphocytic thyroiditis, as well as Hurthle cell adenoma or carcinoma. Prior authors have suggested an increased rate of neoplasms in this patient group when compared with cellular non-Hurthle follicular nodules. Recently, measurement of preoperative TSHR mRNA has proven helpful in identifying patients with thyroid malignancy. The goal of our study is to correlate FNA interpretation with surgical diagnosis and results of preoperative TSHR mRNA testing when available.
Design: The electronic pathology database was searched for thyroid FNA samples interpreted as OHCFN. These samples share in common a cellular Hurthle cell sample with minimal colloid with cells arranged in a predominantly microfollicular pattern. Surgical pathology diagnoses were collated. Preoperative TSHR mRNA elevation (>1.0 ng/ug) was assessed in a subset.
Results: 182 FNA's interpreted as OHCFN over a 10 year period were studied (138 female, 44 male, median age 55.5 years). Histologic follow-up was available for 137 cases (Table 1).
|Hurthle Cell Carcinoma||26||19|
|Papillary Thyroid Carcinoma||9||6.6|
|Hurthle Cell Adenoma||43||31.4|
|Benign Thyroid Nodule||51||37.2|
|Chronic Lymphocytic Thyroiditis||8||5.8|
|Final Histologic Diagnosis||# of patients having normal TSHR mRNA (<1.0 ng/ug)||# of patients having elevated TSHR mRNA (>1.0 ng/ug)|
|Hurthle Cell Carcinoma||3†||2|
|Papillary Thryoid Carcinoma||2||0|
|Hurthle Cell Adenoma||4†||0|
|Benign Thyroid Nodule||3||2†|