Descriptive Study of a Case of Brunner Gland Adenoma, Which Exhibited Dramatic Macroscopic Metamorphosis in 2 Years without Canceration

A 68-year-old Japanese male was shown to have a spherical semipedunculated duodenal
submucosal tumor (SMT) with a small central depression. He was followed up under the tentative
diagnosis of Brunner gland (BG) hyperplasia (BGH) by biopsy. The tumor was found to have turned
inverted dome-shaped with a central depression occupying almost all the top of it 2 years later. The
disrupted surface was uneven, more reddened and lobulated by groove-like excavations, in and
around which the mucosal pattern was obscured and abnormal vessels were observed. The biopsied
specimen was interpreted as BG adenoma (BGA). The tumor was endoscopically resected because
of a risk of complicating malignancy, judged to be completely excised, and definitely diagnosed as
BGA containing no malignancy by the intensive examinations. Though explicitly proves that, contrary
to the reports so far, dramatic macroscopic metamorphosis of BGA does not necessarily herald
malignant degeneration within but is apparently due to disequilibrated blood supply, the present case
implicitly omens, rather than completely excludes, the future possibility of canceration in the lesion on
the grounds of the neoplastic findings.