Diagnostic clues for hyalinizing trabecular tumor on fine needle aspiration cytology.

Objectives: The hyalinizing trabecular tumor (HTT) is a rare benign neoplasm of the thyroid gland. This neoplasm has overlapping cytological features with Papillary Thyroid Carcinoma, Medullary Carcinoma and Follicular Neoplasm with Nuclear Features of Papillary Carcinoma. This can lead to misdiagnosis of malignancy in fine needle aspiration (FNA) cytology specimens with unnecessary total thyroidectomy. The aim of this study is to determine if there are some cytological features that could help us to suspect HTT on FNA specimens and avoid radical surgery. Material and Methods: With this purpose we have collected 6 cases diagnosed of HTT in Hospital Clínico San Carlos of Madrid (Spain) in the last 10 years and reviewed the cytological specimens. Result: We conclude that the presence of hyaline material in FNA specimens of HTT is a constant feature being a diagnostic clue. We must be cautious not to confuse it with dense colloid or amyloid material, the latter seen in Medullary Carcinoma. Papillary architecture and fibrovascular cores are not present in a HTT. Special stains as ki-67, calcitonin and Congo Red staining could help us in achieving the correct diagnosis. Conclusion: We feel the cytopathologists must be aware of the distinguishing features of this lesion, mainly the typical hyaline material to achieve a proper diagnosis and be able to reduce unnecessary aggressive management of these patients.

Sperm protein antigen 17 and Sperm flagellar 1 cancer testis antigens are expressed in a rare case of ciliated foregut cyst of the common hepatic duct.

INTRODUCTION: Ciliated foregut cysts (CFCs) are frequently described in liver, pancreas and gallbladder and generally considered benign although one case of squamous cell metaplasia and five cases of squamous cell carcinoma arising from a ciliated hepatic foregut cyst have been reported. Here we explore two cancer-testis antigens (CTAs), Sperm protein antigen 17 (SPA17) and Sperm flagellar 1 (SPEF1) expression in a rare case of CFC of the common hepatic duct MATERIALS AND METHODS: 3 µm-thick CFC sections were immunohistochemically treated with antibodies raised against human SPA17 or SPEF1. In silico Protein-Protein Interaction (PPI) network and differential protein expression were also investigated RESULTS: Immunohistochemistry revealed SPA17 and SPEF1 in the cytoplasm of ciliated epithelium. SPA17, but not SPEF1, was also detected in cilia. The PPI networks demonstrated that other CTAs are significantly predicted functional partners with SPA17 and SPEF1. The differential protein expression demonstrated that SPA17 was higher in breast cancer, cholangiocarcinoma, liver hepatocellular carcinoma, uterine corpus endometrial carcinoma, gastric adenocarcinoma, cervical squamous cell carcinoma, bladder urothelial carcinoma. SPEF1 expression was higher in breast cancer, cholangiocarcinoma, uterine corpus endometrial carcinoma and kidney renal papillary cell carcinoma CONCLUSIONS: Our study suggests that further characterization of SPA17 and SPEF1 in patients with CFCs might provide significant insights to understand the mechanisms underlying their potential to malignant transformation.

Neuroendocrine Neoplasms in Rare Locations: Clinicopathological Features and Review of the Literature.

INTRODUCTION: Neuroendocrine tumors (NETs) occur more often in lungs, gastrointestinal tract, or pancreas. Data about terminology and grading of NETs in rare locations are scarce and variable, and they have been reported mainly as case reports. MATERIALS AND METHODS: We here describe our experience with NETs in unusual locations. We have reviewed all NETs diagnosed in our institution and summarized their clinicopathological features. We have also reviewed the literature and discussed the main characteristics of NETs in each site. RESULTS: Two hundred and forty-three primary NETs were diagnosed. About 55.2% of patients were men and the mean age was 62 years. About 90.7% of NETs were located in lungs, gastrointestinal tract, or pancreas, and 50.8% of them were low-grade tumors. We identified 13 NETs in rare locations: breast, ovary, endometrium, vulva, uterine cervix, extrahepatic biliary tract, kidney, sinonasal tract, and thymus. Three additional tumors were diagnosed by the senior author in other institution. Patients were asymptomatic or presented with nonspecific symptoms. All NETs were treated with surgery and 31% of patients received adjuvant therapy. There were 10 Grade 3 (62.5%), 2 Grade 2 (12.5%), and 4 Grade 1 (25%) tumors. Mean follow-up was 72 months. About 60% of G3 tumors recurred or progressed. G2 tumors were located in breast, and both patients are stable. About 50% of G1 tumors recurred or progressed (both renal NETs). CONCLUSIONS: NETs in rare locations are heterogeneous, and their behavior does not seem to correlate absolutely with tumor grade. More studies are needed to clarify the role of proliferation rate in these tumors.