title: Malignant potential of small oncocytic follicular carcinoma/Hürthle cell carcinoma: an institutional experience.
abstract: OBJECTIVE
  Oncocytic follicular carcinoma/Hürthle cell carcinoma (OFCA/HCCA) is a rare tumour of the thyroid gland that can be associated with an aggressive clinical course. Most OFCA/HCCAs are large; however, tumours ≤20 mm can occur. The aim of this study was to report our experience with OFCA/HCCA diagnosed at our institution.
  
  
  RESULTS
  One hundred and nineteen cases of OFCA/HCCA were included in this study. Data points included age, sex, size of tumour, method of diagnosis, lymph node (LN) status, and clinical follow-up. The cohort included 37 males and 82 females (average age: 55 years). Preoperative fine-needle aspiration (FNA) was performed in 73 (61%) cases. Twenty-five (21%) tumours measured ≤20 mm and 94 (79%) measured >20 mm. Angioinvasion (AI) was present in 48 (40%) cases, and LN metastases (LNMs) in seven (6%) cases; of these, eight (17%) with AI and 1 (2%) with LNMs measured ≤20 mm. Clinical follow-up was available in 74 (62%) cases (range 12-144 months); 13 (17.5%) developed LNMs and six (8%) regional recurrence. Distant metastases (DMs) were seen in 12 (16%) cases. Two cases with DMs and two with LN recurrence measured ≤20 mm.
  
  
  CONCLUSIONS
  Oncocytic follicular carcinoma/Hürthle cell carcinoma (OFCA/HCCA) can present as small (≤20 mm) tumours, and can be associated with AI, LNM, and DM.
authors: Department of Pathology, Hospital of the University of Pennsylvania, Philadelphia, PA, USA.
authors: Teresa Danielle
authors: TD
authors: Samulski
authors: Shuting
authors: S
authors: Bai
authors: Virginia A
authors: VA
authors: LiVolsi
authors: Kathleen
authors: K
authors: Montone
authors: Zubair
authors: Z
authors: Baloch
mesh_terms: D018249:Adenoma, Oxyphilic; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis / Q000473:pathology*; D009364:Neoplasm Recurrence, Local / Q000473:pathology*; D013964:Thyroid Neoplasms / Q000473:pathology*
keywords: Hürthle cell carcinoma; size; thyroid