Clinically evident metastases of carcinomas to the thyroid gland are rare, particularly from a colorectal primary tumor. We present a case of colonic adenocarcinoma metastatic to the thyroid gland with histopathologic and immunohistochemical findings. A 68-year-old woman with a history of Dukes' stage B colon carcinoma presented a mass in the thyroid gland. The tumor was confirmed to be metastatic adenocarcinoma from the colon. The immunohistochemical findings demonstrated positive staining for cytokeratin 20, low-molecular-weight cytokeratin, villin and carcinoembryonic antigen, but stains were negative for cytokeratin 7 and thyroglobulin.
Adenocarcinoma/secondary* ; Adenocarcinoma/radiography ; Aged ; Carcinoembryonic Antigen/analysis ; Carrier Proteins/analysis ; Case Report ; Colonic Neoplasms/pathology* ; Female ; Human ; Immunoenzyme Techniques ; Intermediate Filament Proteins/analysis ; Keratin/analysis ; Microfilament Proteins/analysis ; Thyroid Neoplasms/secondary* ; Thyroid Neoplasms/radiography ; Thyroid Nodule/radiography ; Thyroid Nodule/chemistry ; Tomography, X-Ray Computed ; Tumor Markers, Biological

Solitary fibrous tumor (SFT) is a rare, soft tissue neoplasm that rarely presents in breast tissue, with only 27 previously reported cases. To our knowledge, only one case of malignant SFT has been reported in the English literature. A 75-year-old Caucasian woman presented to our institution with a 3-month history of a palpable left breast mass. No other symptoms, including nipple discharge or skin changes, were noted. She underwent 3 previous biopsies for right breast masses, all of which were benign, with no evidence of spindle cell neoplasm, atypical hyperplasia, or malignancy. Microscopic examination of the mass demonstrated a classic area of SFT with areas of high-grade anaplastic component. In these areas, the tumor showed atypical epithelioid cells arranged in hypercellular sheets with diminished branching vasculature, nuclear pleomorphism, and increased mitotic count (up to 9/10 high-power fields). This case represents the second case of malignant SFT in the breast.
Aged ; Biopsy ; Breast ; Epithelioid Cells ; Female ; Hemangiopericytoma ; Humans ; Hyperplasia ; Nipples ; Skin ; Soft Tissue Neoplasms ; Solitary Fibrous Tumors

Anastomosing hemangioma (AH) is an unusual benign vascular lesion that commonly occurs in the kidney and genitourinary tract. We report a case of AH in a 49-year-old woman presenting as a mass in the breast, a site which, to the best of our knowledge, has not been previously documented in the English literature. Microscopic examination of the mass revealed a well-demarcated proliferation of anastomosing vascular spaces lined by bland endothelial cells, with focal hobnailing and scattered intravascular fibrin thrombi. No mitotic activity was observed and the Ki-67 proliferative index was low. These features were interpreted as AH, a lesion that may be difficult to distinguish from low-grade angiosarcoma or other benign vascular lesions of the breast which may demonstrate anastomosing channels.Due to the presence of atypical histologic features which can raise suspicion for angiosarcoma on biopsy, complete excision of these lesions is recommended for optimal treatment.