Ductal carcinoma in situ-like structures in metastatic breast carcinoma

Case report: Metastatic ovarian mucinous carcinoma to the breast: diagnostic challenges and pitfalls

Metastases to the breast from extramammary sources are extremely rare, with the ovary, primarily high-grade serous carcinoma, being the most common origin. We report a case of breast metastases from advanced stage ovarian mucinous carcinoma in a 48-year-old female- a case hitherto unreported in the literature. The case is noteworthy for its atypical presentation marked by an areolar rash, clinically suggestive of Paget disease of the nipple. This unique clinical scenario, coupled with histopathological examination revealing in-situ-like carcinoma component, posed a diagnostic challenge in discerning the tumour origin. We emphasize the need for heightened awareness among pathologists to avoid misdiagnosing metastatic carcinomas as primary breast tumours, a potential pitfall with significant clinical implications.

Metastatic "Ductal Carcinoma In Situ-Like" Lobular Carcinoma in a Lymph Node: A Case Report and Review of the Literature

Metastatic breast cancer resembling ductal carcinoma in situ (DCIS) is a rare phenomenon. In this article, we present a unique case of metastatic lobular carcinoma with DCIS-like morphology in the left axillary lymph nodes of a 52-year-old female. She presented with 2 lesions in the left breast on mammography, and a mastectomy with axillary lymph node dissection was performed. Gross examination showed a 3.5 × 2.5 × 1.0 cm indistinct tumor in the lower outer quadrant and a 2.5 × 2.5 × 1.8 cm tumor in the upper outer quadrant. Microscopic assessment revealed a pleomorphic lobular carcinoma in the lower outer quadrant and a grade 2 invasive ductal carcinoma in the upper outer quadrant. Sixteen of the 17 axillary lymph nodes showed metastatic lobular carcinoma with foci of solid and comedo-type DCIS-like features. Immunohistochemical analysis of the primary and metastatic lobular carcinoma showed no expression of E-cadherin and p63 antibodies. To our knowledge, metastatic lobular carcinoma exhibiting this pattern has not been reported. The case suggests that lobular carcinoma can morphologically recreate a primary microenvironment at a distant site and simulate in situ growth. Recognition of this pattern is important to avoid misdiagnosis.

Metastatic mammary carcinoma with DCIS-like morphology: a report of two cases

Two cases of breast carcinoma with lymph node metastases are presented. In each case the metastases demonstrated the unusual phenomenon of resembling either cribriform or comedo DCIS. Furthermore both cases had the additional rare feature of demonstrable lymphatic involvement by DCIS-like carcinoma.