S6285 Early Stage Gastric Squamous Cell Carcinoma in a Patient With Lynch Syndrome

Introduction: Squamous cell carcinoma (SCC) of the stomach is a gastroenterological malignancy that is exceedingly rare, accounting for approximately 0.04% to 0.2% of all gastric malignancies, and having only been documented less than 100 times in case reports to date. Being so rare, the pathogenesis of primary gastric SCC remains unclear. Due to its aggressive nature, it is also often diagnosed at a late stage, attributing to it a poor prognosis. Case Description/Methods: A 63-year-old woman with prior medical history of Lynch syndrome, colon cancer at age 27 status post resection, recent traumatic brain injury (TBI), and diabetes type 1 presented to the emergency department with hypoglycemia and fatigue that acutely worsened after undergoing bowel prep for outpatient esophagogastroduodenoscopy (EGD) and colonoscopy. The patient had previously undergone magnetic resonance imaging (MRI) abdomen as part of workup for intractable lower abdominal pain associated with bloating and dyspepsia. The MRI revealed gastric wall thickening concerning for malignancy. The patient was stabilized and underwent EGD during admission that revealed an ulcerated mass in the gastric antrum covering three fourths of the pylorus without obstruction. Biopsy of the mass sent to pathology revealed SCC. The patient then underwent a follow-up PET scan due to strong suspicion for metastasis. PET scan revealed no other sites of malignancy or affected lymph nodes, suggesting primary stomach SCC. An oncology consultation recommended immunotherapy, but the family decided to pursue palliative care given her acute decline in the setting of recent TBI. The patient was discharged on home hospice. Discussion: The case of a 63-year-old woman with Lynch syndrome presenting with primary gastric SCC is highly unusual. Lynch syndrome is predominantly associated with adenocarcinomas, of which one is gastric adenocarcinoma, rather than SCC. The occurrence of SCC in this context raises questions as to whether this was related to her Lynch diagnosis or just occurred by random chance. This patient’s diagnosis of SCC of the stomach at a localized stage is particularly notable considering its typically poor prognosis. In a patient that was not already experiencing acute decline related to TBI, this would likely have been an opportunity to intervene surgically. This case highlights the importance of vigilance for atypical malignancies in patients with Lynch syndrome. Due to the rarity of this cancer, more case reports are needed to determine the best course of action in patient’s presenting with gastric SCC, particularly at an early stage.