Are there specific cytologic features that can predict BRAFV600E mutational status of papillary thyroid carcinoma in fine-needle aspiration specimens?

BACKGROUND: BRAFV600E mutation is the most common molecular alteration found in papillary thyroid carcinoma (PTC) and has been linked to recurrent disease or possibly more aggressive behavior. Some studies have reported sickle-shaped nuclei (SSN) and plump pink cells (PPC) to be predictive markers of BRAF mutation in FNA cytology. We aimed to evaluate the reproducibility of the aforementioned cytologic features. METHODS: A computerized search for diagnosed PTC surgical pathology cases tested for BRAFV600E mutation by Sanger DNA sequencing was performed. Blinded to BRAF results, the corresponding cytology was reviewed for presence of SSN and PPC. Classic nuclear PTC (CNPTC) features, cystic change, and psammoma bodies were also evaluated. The results were correlated with BRAFV600E mutational status and histologic subtypes. RESULTS: Study cohort consisted of 113 cases (74 BRAFV600E mutated, 39 BRAFV600E wild type). SSN and combined CNPTC /SSN had positive predictive value of 74% and 75%, respectively. CNPTC showed 92% sensitivity and 20% specificity. Psammoma bodies had 92% specificity and 5% sensitivity. The presence of combined PPC/SSN showed 80% specificity, 27% sensitivity, and diagnostic accuracy of 45%. CNPTC was seen in 60/61 (98%) SSN and 45/45 (100%) PPC. There was no significant statistical association between SSN, PPC, and CNPTC with specific histologic subtypes and BRAF mutational status. CONCLUSION: CNPTC is sensitive but not specific for BRAF mutational status. SSN, PPC, and CNPTC are not predictive markers for the presence of BRAF mutation or histologic subtypes. Additional studies may be needed to further corroborate these findings.

Primary Leiomyosarcoma of the Mesentery: A Case Report With Review of Literature.

Mesenteric leiomyosarcoma (LMS) is a rare gastrointestinal mesenchymal tumor. It was often misdiagnosed as a gastrointestinal stromal tumor (GIST) until the introduction of immunohistochemistry staining (IHC) in 1998. Currently, a positive IHC staining for smooth muscle markers represents the main diagnostic modality. Herein, we present a case of Mesenteric LMS in a 68-year-old woman, who presented with nausea, vomiting, and abdominal pain and was found to have a right-sided mesenteric tumor encasing the right ureter, with right hydroureteronephrosis. The patient underwent surgical removal of the tumor and IHC stains were compatible with LMS. She achieved remission until she developed recurrence 12 months after initial diagnosis and subsequently expired due to postoperative complications when re-resection was attempted. Typically, mesenteric LMS carries a poor prognosis with a propensity for hematogenous metastasis. In the absence of a standardized protocol for therapy, early surgical resection is the only known curative modality but with a high risk of recurrence.