A 55-year-old woman was admitted to hospital with epigastric discomfort and generalized
weakness of 2 months’ duration. On physical examination there was a mass on palpation
in the thyroid area. Esophagogastroduodenoscopy (Figure [1]) revealed a polypoid lesion on the lesser curvature of the antrum. At 2 weeks later,
when we performed esophagogastroduodenoscopy (Figure [2]) for polypectomy, we found a depressed lesion where previously the polypoid lesion
had been located. Histopathological evaluation of the endoscopic biopsy specimen disclosed
a well-differentiated adenocarcinoma. Endoscopic ultrasonography (EUS) revealed a
hypoechoic mucosal thickening with an internal anechoic cystic area in the lateral
margin of the lesion. Because the patient refused operation, endoscopic mucosal resection
was carried out. Histopathological evaluation of the endoscopic mucosal resection
specimen (magnification × 200) disclosed mucin pools including a well-differentiated
adenocarcinoma which invaded the muscularis mucosa and a considerable part of the
submucosa. Although she was scheduled to return for operation 2 months later, we were
not able to follow up this patient any further.
Figure 1 Esophagogastroduodenoscopy showed a polypoid lesion with an irregular surface, on
the lesser curvature of the antrum.
Figure 2 At the same location 2 weeks later, follow-up esophagogastroduodenoscopy showed a
depressed lesion with redness and an irregular base and margin.
Mucinous gastric adenocarcinoma is a rare subtype of gastric adenocarcinoma which
comprises approximately 3 - 5 % of all gastric carcinomas [1]. The terms mucoid, colloid, or gelatinous have been used by different authors to
describe this carcinoma subtype [2]. Although this histological subtype has long been recognized, its characteristics
have seldom been reported. Whether mucinous gastric carcinoma behaves as aggressively
as a mucinous colorectal carcinoma is still controversial [3]. While some studies have supported a worse prognosis when there is mucin content
[4], others have reported an indolent presentation [2] or refuted any difference [1]. However, there has been no report about the characteristic of morphological change
in the same lesion of mucinous adenocarcinoma. The present case demonstrated a mucinous
gastric adenocarcinoma with a morphological change from polypoid to depressed lesion
within a short period, which was diagnosed histologically after endoscopic mucosal
resection.
