title: Occult medullary carcinoma of thyroid with lymph node metastases: a case report.
abstract: BACKGROUND
  Occult thyroid malignancies presenting with secondary neck masses as the first clinical manifestation is well known. Although rare, medullary carcinoma serves a potential source for lymph node metastases. The characteristic cytomorphology of medullary thyroid carcinoma (MTC) should clinch the diagnosis. Further, fine needle aspiration cytology (FNAC) of the ultrasonography-detected occult nodules in thyroid serves as a useful preoperative diagnostic tool.
  
  
  METHODS
  A 22-year-old man presented with left-sided neck masses of 1 year duration. FNAC smears of the neck masses revealed cytomorphology characteristic of MTC. Ultrasonography of the thyroid led to ruling out the presence of an occult nodule and detected an 8-mm nodule in the left thyroid lobe. Ultrasound-guided FNAC of the nodule showed features similar to those with FNAC of the neck masses. Surgical resection of thyroid and neck masses further confirmed the diagnosis of a primary occult MTC with lymph node metastases.
  
  
  CONCLUSIONS
  FNAC smears of lymph node masses showing the distinct cytomorphology of MTC should prompt suspicion for occult primary in thyroid. Ultrasound-guided FNAC of these occult nodules, if detected, further serves a diagnostic tool for accurate preoperative diagnosis when metastasis presents as the first clinical manifestation of an occult primary.
authors.affiliation: Departmentof Pathology, BYL Nair Hospital and TN Medical College, Mumbai, India. sangukini@yahoo.co.in
authors.forename: Sangeeta
authors.initials: S
authors.lastname: Kini
authors.forename: Chinmay K
authors.initials: CK
authors.lastname: Saraf
authors.forename: Leena P
authors.initials: LP
authors.lastname: Naik
authors.forename: Vimla B
authors.initials: VB
authors.lastname: Shah
authors.forename: Gururaj V
authors.initials: GV
authors.lastname: Puranik
authors.forename: Prema K
authors.initials: PK
authors.lastname: Vartakvi
mesh_terms: D000328:Adult; D044963:Biopsy, Fine-Needle; D018276:Carcinoma, Medullary / Q000175:diagnosis* / Q000473:pathology; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000473:pathology