What happened, in summary

A 32-year-old woman presented in April 2016 with a painless right-breast lump that had enlarged over 3 months. Examination found a 6 × 4 cm mass and a 1.5 × 1 cm right axillary lymph node. Core biopsy initially suggested grade 1 invasive ductal carcinoma, and the tumour was ER positive, PR positive and HER2 positive. Her disease was considered Stage III.

She received only 1 cycle of neoadjuvant doxorubicin-cyclophosphamide and paclitaxel-trastuzumab-based therapy before being lost to follow-up for 1 year. When she returned, the breast lesion was ulcerated, foul-smelling and bleeding. Her hemoglobin fell from 7.8 to 6.4 g/dL over 3 days, and she received 3 units of packed red cells. Imaging showed no lung, abdominal or bone metastases.

She underwent a right modified radical mastectomy. Final pathology revealed an 11 × 9 × 7 cm primary neuroendocrine carcinoma involving all quadrants of the breast. Four of 11 lymph nodes contained tumour. The cancer was positive for neuron-specific enolase and synaptophysin as well as ER, PR and HER2.

She developed a 3 cm area of flap necrosis that was treated with serial debridement and dressings. At the latest follow-up she was stable and receiving adjuvant chest-wall radiation together with chemotherapy and trastuzumab-based treatment.