Mucinous cystadenocarcinoma of the breast: a new entity with broad differentials-a case report.

BACKGROUND: Mucinous cystadenocarcinoma is a rare and recently described primary breast cancer with strikingly similar histomorphology to ovarian, pancreatic, and gastrointestinal counterparts. The diagnosis cannot be made until the metastatic lesion is ruled out. CASE PRESENTATION: We are reporting the case of a 65-year-old woman with primary mucinous cystadenocarcinoma of the breast while exploring clinicopathological features and approach to diagnosis. Though the immunohistochemistry panel of CK7, CK20, CDX2, SATB2, PAX8, mammoglobin, and GATA3 plays a crucial role in ruling out metastasis but aberrant CK20 positivity was seen in our case, the final diagnosis was made after a complete radiological workup. We also noted strong membranous HER2-protein expression and HER2-gene amplification by fluorescence in situ hybridization while in literature this tumor is reported to show mainly triple-negative basal type immunophenotype. CONCLUSION: A combined clinic-radio-immunohistochemical approach is essential to make a diagnosis of primary mucinous cystadenocarcinoma.

Long-term survival after hand-assisted laparoscopic approach of primary retroperitoneal mucinous cystadenocarcinoma in male: case report and review of literature.

BACKGROUND: Primary retroperitoneal mucinous cystadenocarcinoma (PRMC) is a rare disease and mostly occurs in females, and there are only three male cases described in the literatures without long-term follow-up. CASE REPORT: A 59-year-old male presented with a left retroperitoneal cystic mass (7.5 ´ 7 ´ 3 cm) that upwardly displaced the left kidney and caused abdominal discomfort. The tumor was totally excised by the hand-assisted laparoscopic method without complications or recurrence in a follow-up period of 79 months. The etiology from coelomic metaplasia of peritoneal epithelium was proved by a spectrum of diverse cells (benign, borderline malignant, and malignant cells) during pathological examination. RESULTS: This is the fourth male case of PRMC in the world with a favorable outcome after hand-assisted laparoscopic excision, and this is also distinct by the longest follow-up period in this disease entity. CONCLUSIONS: Because of its low-malignant potential and recurrence rate, surgical excision is still the best choice of treatment, but the least invasion method should be adopted in front.