TALL CELL VARIANT OF PAPILLARY THYROID-CARCINOMA - A CYTOHISTOLOGIC CORRELATION

OBJECTIVE: To identify the cytologic characteristics of the tall cell variant of papillary thyroid carcinoma in fine needle aspiration biops ies and make a cytohistologic correlation. STUDY DESIGN: The study gro up consisted of six patients subjected to fine needle aspiration biops y of the thyroid prior to surgical resection of the tumor. RESULTS: Ni neteen cases of the tall cell variant were identified in 229 cases of papillary thyroid carcinoma (8.5%) from 1957 to 1993. Six cases had as pirates with tall cells. The patients were females with a median age o f 43 years, and all had aggressive neoplastic diseases. The tumors had > 30% tall cells. The fine needle aspiration biopsy findings included nuclear grooves and abundant oxyphilic cytoplasm (100%), pseudonuclea r inclusions (83.3%) and ground glass chromatin (67%). The majority of neoplastic cells had a nuclear/cytoplasmic ratio of 1:2. A tadpole sh ape was observed in noncohesive cells, and a respiratory epithelium-li ke arrangement was seen in cohesive cells. CONCLUSION: Fine needle asp iration biopsy is the best method of identifying tall cells preoperati vely. Nuclear and cytoplasmic changes should be added to make a firm d iagnosis of the tall cell variant and to rule out columnar cell carcin oma or squamous metaplasia in goiter or usual thyroid papillary carcin oma.