Cytological features of medullary thyroid carcinoma in ascitic effusion

Abstract

ascitic fluid, cytology, medullary thyroid carcinoma Malignant serous effusions are often encountered in cytopathology.The most common secondary malignancy leading to body cavity effusions is adenocarcinoma. The main primary sites are lung, breast, ovary, gastrointestinal (GI) tract and pancreas. 1-3 In addition to adenocarcinoma, almost any malignant tumor can be the underlying cause of an effusion, including hematopoietic malignancies, squamous cell carcinoma, and melanoma, among others. 2 Thyroid carcinoma only rarely metastasizes to the serous cavities with an incidence of <0.1%. 3,4 Among thyroid malignancies, papillary thyroid carcinoma is the most frequently described in the literature. [2][3][4][5] Other less commonly reported primary thyroid tumors include anaplastic thyroid carcinoma, poorly differentiated carcinoma, and Hurthle cell carcinoma. 4,6 Reportedly, metastases from thyroid primaries are more frequent to the pleural cavities. 7 Herein, a case of medullary thyroid carcinoma metastatic to the peritoneal cavity is described. To our knowledge, medullary thyroid carcinoma in ascitic fluid has not been described before.A 38 year-old woman was evaluated at our institution due to abdominal pain secondary to ascites. The patient had a history of dysplastic nevi syndrome and medullary thyroid carcinoma (MTC) diagnosed at an outside institution 3 years prior. During the 3 years following her thyroid surgery, she continued to progress requiring neck revision for persistent nodal disease, as well as developing pulmonary and liver nodules which were not biopsied.The patient did not have features of multiple endocrine neoplasia syndrome II (MEN II) and was RET proto-oncogene germline mutation negative. A paracentesis was performed. Over 1000 cc of yellow fluid was sent for cytological analysis, from which 2 cytospins and 1 cell-block were prepared. The cytospins were very cellular and were composed predominantly of mixed inflammation, numerous macrophages and some identifiable mesothelial cells. There were a few tridimensional cell clusters that stood out from the benign/inflammatory background ( Figure 1A). The clusters were composed of mild to moderately pleomorphic cells with occasional nuclear membrane irregularities and an inconspicuous nucleolus displaying significant nuclear molding. Nuclear size was comparable or only slightly larger than the nuclear size of the background macrophages. The cytoplasm was moderate in amount and the clusters displayed community borders ( Figure 1B). Occasional acinar formations were appreciated in the cell-block ( Figure 1C). In addition to exploring the possibility of metastasis from her known MTC and due to the exceedingly rare occurrence of thyroid primaries metastasizing to the peritoneal cavities, immunostains (IHC) were performed for confirmation. The cells of interest were positive for TTF-1, MOC-31, chromogranin and calcitonin and negative for WT-1, PAX-8 and calretinin ( Figure 1D). The diagnosis of metastatic MTC was rendered. Serological levels of calcitonin ...

Fighting Thyroid Cancer with Microgravity Research

“…Approximately 30% of patients suffering from thyroid cancer develop metastases [69] and the incidence of distant metastasis after thyroidectomy remains between 7% and 23% [70]. In rare cases metastasis is associated with malignant ascites (especially described for medullary thyroid cancer [71]). Metastatic ascites containing multicellular spheroids can promote chemo-resistance and recurrence [72].…”