Gastric obstruction secondary to metastatic breast cancer: a case report and literature review

INTRODUCTION: Gastrointestinal tract soft tissues metastasis is a well-known occurrence with invasive lobular breast cancer subtypes. Gastric involvement is more common, with reports of both diffuse and localized involvements. Usually, a gastric localized involvement presents as wall thickening with an appearance similar to that of a gastrointestinal stromal tumour; rarely does a localized metastatic deposit grow aggressively to present as a large tumour causing obstructive symptoms. Our case highlights one such unusual presentation in a patient presenting with non-specific gastrointestinal symptoms. To the best of our knowledge, there have been no previous reports on a similar presentation occurring from a localized metastasis. CASE PRESENTATION: A 65-year-old Caucasian woman awaiting an outpatient oral gastroduodenoscopy for symptoms of intermittent vomiting, epigastric pains and weight loss of six weeks’ duration presented acutely with symptoms of haematemesis and abdominal distension. An initial contrast-enhanced computed tomography scan showed a grossly dilated stomach with a locally advanced stenosing tumour mass at the pylorus. Our patient had a history of left mastectomy and axillary clearance followed by adjuvant endocrine therapy for an oestrogen receptor- and progesterone receptor-positive, grade 2, invasive lobular breast cancer. The oral gastroduodenoscopy confirmed the computed tomography findings; biopsies of the pyloric mass on immunohistochemistry stains were strongly positive for pancytokeratin and gross cystic disease fluid proteins, consistent with an invasive lobular breast cancer metastasis. She received a palliative gastrojejunal bypass and her adjuvant endocrine treatment was switched over to exemestane. CONCLUSION: Our case highlights the aggressive behaviour of a localized gastric metastasis that is unusual and unexpected. Gastrointestinal symptomatology can be non-specific and, at times, non-diagnostic on conventional mucosal biopsies. A high index of clinical suspicion in patients with a previous history of invasive lobular breast cancer can aid in an early diagnosis and treatment. A combined treatment approach with chemoendocrine therapies achieves remission and improves patient survival.