Cystic Breast Cancer. A Confusing Entity. Study of 8 Cases at Dakar University Surgical Oncology Unit

Introduction: Cystic breast cancer is a rare entity. Breast cysts are most often benign. The clinical characteristics of malignancy are not specific. Objective: To report a series of malignant cystic tumors of the breast and to describe their different characteristics. Materials and Methods: This was an observational study carried out between January 2018 and October 2021 at the Dakar university surgical oncology unit. We studied the clinical appearance, imaging, histopathology, extent of disease and treatment. We did not include cases of pure, single, or multiple chronically progressive cysts. Results: There were 8 patients, 6 women and 2 men. The average age was 44. All patients presented with a palpable unilateral deforming skin mass without inflammatory character. One patient presented with a bloody discharge. The cyst was multilocular without intracystic growth in 2 cases and presented a growth signal in 6 cases. Imaging was ACR 3 in 5 cases and ACR 4 in 3 cases. Histopathology found 6 invasive carcinomas including 2 papillary, 3 Invasive Carcinoma of No Special Type (ICNST), 1 lobular carcinoma as well as one case of lobular carcinoma in situ of the comedocarcinoma type in women and 2 ICNST in men. The extension workup was found in only 1 male patient in the presence of metastases. Treatment included chemotherapy, mastectomy and radiotherapy for 6 of the patients. There wasn’t any complete response for invasive cases. Survival is 100% to date. Conclusion: Cystic breast tumors sometimes hide the cancer that is difficult to diagnose. The prognosis seems favorable, however.