Aggressive behavior of Her-2 positive colloid breast carcinoma: A case report in a metastatic breast cancer

Introduction: Colloid breast carcinoma is a rare form of invasive ductal cancer characterized by large amount of
mucous deposition. It is considered as an indolent cancer that usually affects older women. Colloid breast
carcinoma generally expresses estrogen and progesterone receptors but negative for Her-2. Recommended
surgery and adjuvant treatment of colloid breast carcinoma is not well-established.
Presented case: A 46 years-old woman presented as an aggressive colloid breast carcinoma showing skin ulceration,
enlargement of multiple axillary lymph nodes and a metastasis in the pleura at diagnosis. The primary
tumor showed strong positive expression of estrogen, progesterone as well as Her-2 receptors. The patient was
treated with 6 cycles of paclitaxel and carboplatin followed by mastectomy, radiotherapy, and hormonal
therapy. Patient tolerated the treatment course and showed improvement both in the locoregional control and
pleural metastasis.
Discussion: Colloid breast carcinoma with aggressive clinical course is rarely found. Nodal involvement as a sign
of poor prognosis in colloid breast carcinoma ranges only between 12 and 19%. Therefore, axillary node
clearance is usually excluded during the surgery of colloid breast carcinomas. However, in the presence of highrisk
characteristics, mastectomy involving axillary lymph node dissection is still contentious. In patients with
Her-2 overexpression, treatment using anti-Her2 (trastuzumab) is also still disputed in colloid breast carcinoma
because of the higher resistance rates.
Conclusion: Although clinically aggressive colloid breast carcinoma is rare, thorough clinical assessment and
immediate treatment initiation will be beneficial for patients with high risk of relapse and metastatic spread.