Gallbladder metastasis from occult lobular breast
carcinoma: A case report

Introduction: Bones, lungs, brain and liver are the most common metastatic sites of breast carcinoma, although invasive lobular carcinoma can give metastases to less common sites, such as the gastrointestinal tract and the female genital tract.
Case presentation: We present the case of a 57-year-old female with colic abdominal pain that was sent to surgery for cholecystectomy. Histopathology revealed a poorly cohesive individual or in single file neoplastic cells infiltrating all layers of the gallbladder. Immunohistochemistry revealed these cells to be CK 116, CK7, GCDFP-15, ER and PR positive, and CK20, HER-2, S-100 and E-cadherin negative. PET/CT showed numerous lytic bone lesions, but ultrasound, mammography, MRI and PET/CT revealed no breast mass.
Conclusion: Although rare and poorly understood, metastases of invasive lobular carcinoma to gallbladder do exist in a minor percentage of patients, presenting usually as exacerbated cholecystitis. The problem are silent cases and patients with no history of breast carcinoma. This case is unique in that even after the diagnosis of metastatic lobular breast carcinoma to the gallbladder, the primary tumour of the breast was not detected.