Breast Tumor Resembling Tall Cell Variant of Papillary Thyroid Carcinoma: A Solid Papillary Neoplasm With Characteristic Immunohistochemical Profile and Few Recurrent Mutations.

OBJECTIVES: Breast tumor resembling tall cell variant of papillary thyroid carcinoma (BTRPTC) is a rare breast lesion that is unrelated to thyroid carcinoma. Morphologically, it shows a solid papillary lesion with bland cytology, eosinophilic/amphophilic secretions, nuclear grooves, reversal of nuclear polarity (recently described), and nuclear inclusions. Clinical course is often uneventful with few exceptions reported in the literature. Herein, we report three additional cases. METHODS: Immunohistochemical staining and next-generation sequencing was performed on all three cases. RESULTS: The lesional cells on all cases were positive for cytokeratin 5 and S100, with weak expression/lack of estrogen receptor. No staining was observed for myoepithelial markers (p63 and myosin heavy chain) around the lesion. IDH2 mutations were identified in two cases at nucleotide 172 (cases 1 and 3). ATM gene mutation was identified in cases 2 and 3 and PIK3CA mutation in case 3. All patients are currently without disease. CONCLUSIONS: BTRPTC is a slow-growing neoplastic lesion that needs to be distinguished from other papillary lesions for optimizing therapy.

Giant Cell Arteritis of the Female Genital Tract With Occult Temporal Arteritis and Marginal Zone Lymphoma Harboring Novel 20q Deletion: A Case Report and Literature Review.

Giant cell arteritis (GCA) is an immunologically mediated vasculitis of large and medium-sized vessels, typically affecting the cranial arteries and usually occurring in the elderly. GCA of the female genital tract is extremely rare with only 31 cases reported in the English literature. An 83-year-old white female with postmenopausal vaginal bleeding revealed an endometrial polyp on pelvic ultrasonography following which polypectomy and subsequently hysterectomy with bilateral salpingo-oophorectomy was done. Microscopy revealed a well-differentiated endometrioid adenocarcinoma. Interestingly, classic GCA involving numerous small to medium-sized arteries of the cervix, myometrium, bilateral fallopian tubes, and ovaries was also identified. Hematologic evaluation revealed marginal zone lymphoma with an exceptionally rare 20q deletion. Bilateral temporal artery biopsy was done subsequently, which exhibited GCA on microscopy. Corticosteroid was started that improved her polymyalgia rheumatica symptoms. The patient is on follow-up for 3 years and is doing well. To our knowledge, this is the first case of GCA of the female genital tract associated with a lymphoma and the second case of marginal zone lymphoma with the novel 20q deletion.