We report an autopsy case of a 35-yr-old man with familial visceral myopathy, a cause of primary intestinal pseudo-obstruction. The patient died from complications of familial visceral myopathy, sepsis, and generalized signet-ring cell carcinomatosis. The patient had massive distension of the large and small intestines, a dilated thickened esophagus, and fibroneoplastic adhesions between intra-abdominal and thoracic structures. This case provides an observation, not previously described in cases of familial visceral myopathy, which is fibrosis and atrophy of the outer longitudinal smooth muscle of the small bowel, alternating to involve only the inner smooth muscle layer of the large bowel. This case shows how a malignant neoplasm can compound the pathology of familial visceral myopathy.