Cytologic Features of Diffuse Sclerosing Variant of Papillary Carcinoma: Cytohistopathologic Analysis of 16 Cases

ABSTRACT

BACKGROUND: The exact preoperative diagnosis of diffuse sclerosing papillary carcinoma (DSPC) is required for aggressive surgical treatment due to its extended involvement with thyroid and neck lymph nodes. The present study investigated the cytomorphologic characteristics of DSPC and identified cytologic features for preoperative diagnosis of DSPC. METHODS: A retrospective review of cytologic and histologic features of 16 patients diagnosed with DSPC after thyroidectomy and underwent preoperative fine needle aspiration cytology (FNAC) was performed. RESULTS: Prominent psammoma bodies were observed in 16 (100%) and 10 (62.5%) cases of histology and FNAC, respectively. Lymphocytes were observed in nine (56.2%) and four (25.0%) cases, and squamous cells were noted in seven cases (43.7%) and one case (6.2%) on histology and FNAC, respectively. Nuclear grooves and inclusions, which are characteristics of papillary carcinoma, were observed in FNAC and histology slides in all 16 cases. CONCLUSIONS: DSPC displays prominent psammoma bodies and characteristic nuclear features of papillary carcinoma such as nuclear groove and inclusion in FNAC. However, the preoperative diagnosis of DSPC using only FNAC could be difficult due to the absence of other characteristic features such as lymphocytes and metaplastic squamous cells.