Amyloid tumor of the stomach simulating an obstructing gastric carcinoma: case report and review of the literature

Systemic amyloidosis is known to rarely affect the stomach [1] [2] [3] [4] [5]. A 59-year-old male patient presented with intermittent nausea, vomiting, daily bowel movements, and weight loss of 20 kg over 2 months. His past medical history was significant for arterial hypertension, prostate cancer for 10 years, multiple myeloma, and recent renal failure. Barium upper gastrointestinal X-ray series revealed a large constricting lesion in the gastric antrum and proximal duodenum suggestive of malignancy ([Fig. 1]). Upper gastrointestinal endoscopy revealed a large, fungating, friable mass which obstructed nearly 75 % of the prepyloric lumen ([Fig. 2]). Pathological analysis of the biopsies revealed amyloid deposits on the muscularis mucosae.

Fig. 1 Barium meal showing a constricting lesion of the gastric antrum and proximal duodenum suggestive of gastric cancer.

Fig. 2 Endoscopic appearance of a large circumferential, fungating, friable mass in the prepyloric antrum.

Exploratory laparotomy found a 4 × 5 cm obstructing soft mass in the prepyloric antrum. A Billroth II partial gastrectomy was performed. Pathological analysis showed infiltration of the muscularis mucosae and muscularis propria by amyloid and no malignancy. The postoperative course was marked by progressive impairment of the gastrointestinal motility. The patient died 5 months later.

Gastric outlet obstruction by an amyloid tumor is exceptional, with five published reports ([Table 1]). All patients were treated with surgery, a most reliable management of gastric outlet obstruction. In patients with known systemic amyloidosis who present with gastric outlet obstruction, regional amyloid deposition should be included in the differential diagnosis, along with other, more common causes such as ulcer or carcinoma. The obstruction can co-exist with a previously unrecognized amyloid gastrointestinal motility disorder, which can worsen the outcome.

Table 1 Previously published cases of gastric amyloid tumor causing gastric outlet obstruction. Study Age/gender Underlying disorder Duration of GI disorder Diagnosis Treatment Outcome/cause of death Golden 1 66/F Primary amyloidosis 16 years Surgical specimen Partial gastrectomy Died from malnutrition (69 days)* Shnider and Burka 2 52/F Multiple myeloma 6 months Surgical specimen Partial gastrectomy Died from anastomotic leak (15 days) Klingenberg 3 63/M Primary amyloidosis 1.5 years Surgical specimen Partial gastrectomy Died from pulmonary embolism (5 days) Lewis 4 68/F Multiple myeloma months** Endoscopy Gastrojejunostomy Died from GI bleeding (3 months) Cryer and Kissane 5 37/F Multiple myeloma 1 year Surgical specimen Gastrojejunostomy Not reported * I. e., days after surgery; GI, gastrointestinal.** the authors did not specify how many days after surgery.

References

• 1 Golden A. Primary systemic amyloidosis of the alimentary tract.  Arch Int Med. 1945;  75 413-416
• 2 Shnider B, Burka P. Amyloid disease of the stomach simulating gastric carcinoma.  Gastroenterology. 1955;  28 424-430
• 3 Klingenberg P H. Amyloidosis of gastrointestinal tract simulating gastric carcinoma.  Am J Surg. 1958;  96 713-715
• 4 Lewis M. Gastrocamera findings in a patient with gastric amyloidosis and multiple myeloma.  Gastrointest Endosc. 1968;  14 190-193
• 5 Cryer P E, Kissane J M. Gastric outlet obstruction in a patient with multiple myeloma.  Am J Med. 1980;  68 141-148