Breast metastasis from gastric signet ring cell carcinoma is extremely rare in clinical practice. The estimated incidence is 0.5–1.3%. There are few cases reported in the literature (approx. less than 60) of breast metastasis from gastric signet ring cell carcinoma, and due to the rare association between gastric cancer and its extension to the breast, it is difficult to establish the diagnosis. Clinical history, histological findings, and immunohistochemical markers are helpful in distinguishing primary breast cancer from breast metastasis of gastric cancer. The treatment for breast metastasis from gastric carcinoma remains controversial. The prognosis of breast metastasis from gastric carcinoma is generally poor. We report a case of breast metastasis of gastric signet ring cell carcinoma in a 38-year-old woman. She started chemotherapy with ramucirumab, paclitaxel, and irinotecan. Three months later, a combined 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography showed a complete response. This is the first reported case of breast metastasis from gastric signet ring cell carcinoma with a complete response.

Introduction: Diabetic mastopathy (DM) is an uncommon, benign entity of self-limiting fibro inflammatory breast disease. It is associated with type 1 diabetes mellitus (T1DM). DM represents a collection of clinical, radiological, and histological findings on the breast. Case report 1: We report a 37-year-old woman, with T1DM diagnosis. The chief complaint included a 2-week history of an enlarging left breast lump. BI-RADS 4c was diagnosed in mastography. Pathology study showed DM. Case report 2: A 42-year-old woman with T1DM diagnosis noted an enlarging left breast mass. BI-RADS 4c lesion was diagnosed by mastography. DM was determined by pathology study. Literature review: The association between T1DM and DM has been related to microvascular complications and is clinically indistinguishable from breast cancer. Breast ultrasound is the standard of choice for DM diagnosis. Pathogenesis of DM remains unknown. As a benign disease DM does not need surgery, only surveillance has been recommended. Conclusion: The DM should be considered in patients with microvascular complications of T1DM.