Teaching NeuroImage: Cutaneous Lesions and Leptomeningeal Carcinomatosis in Gastric Signet-Ring Cell Carcinoma.

A 61-year-old man with a 47 pack-year smoking history presented after a month of positional headache, blurry vision, early satiety, and weight loss. His neurologic examination demonstrated bilateral papilledema but was otherwise unremarkable. Lumbar puncture was significant for 40 cm H2O opening pressure, 27 mg/dL of glucose, 48 mg/dL of protein, 5 red blood cells, 8 leukocytes, and atypical keratin-positive cells. Skin examination revealed multiple nodules that had appeared a week before symptom onset (Figure, A and B). An MRI examination showed enhancement of (Figure, C) the facial and vestibulocochlear nerve complex (Figure, D), trigeminal nerve (Figure, E), patchy spinal leptomeninges, and (Figure, F) cauda equina nerve roots. Skin lesion biopsy and CSF cytology both revealed signet-ring carcinoma. Subsequent endoscopy revealed primary gastric cell adenocarcinoma. Leptomeningeal carcinomatosis is rare and occurs in only 0.14%-0.24% of all gastric carcinomas.1,2 Further, cutaneous and concurrent leptomeningeal spread of gastric cancer is extremely rare. This case highlights the relevance of a general examination and consideration of comorbidities in approaching an unclear neurologic presentation, particularly when considering possible leptomeningeal disease.