Ectopic gastric antrum was misdiagnosed as liver abscess?

Case data

A 57-year-old male patient was admitted to our hospital on May 4, 2014 with the main complaint of "discovery of cystic mass in the liver for 4 years"

Physical examination on admission: body temperature 36.

Abdominal ultrasound on admission showed:

(1) Diffuse liver echo changes (fatty liver)

(2) The cystic echo of the left hepatic lobe (50 mm × 48 mm, with poor internal sound transmission), abdominal MRI showed: there is a lack of blood supply in the anterior and lower part of the left hepatic lobe near the gastric antrum, and benign lesions should be considered (Figure 1) ; A kind of round, long T1 and long T2 signal shadows were seen at the anterior and lower part of the left hepatic lobe near the gastric antrum.

Figure 1 MRI results of abdomen

Figure 2 Postoperative pathological results (HE staining) (parapyloric) microscopic examination showed hypertrophy of the gastric wall muscle layer, ectopic pancreas and cyst formation, and the cyst wall was covered with differentiated mucous columnar epithelium a: ×200; b: ×400

discuss

Heterotopic pancreas refers to pancreatic tissue located elsewhere that is neither anatomically nor vascularly connected to the pancreas

The diagnosis of ectopic pancreas mainly relies on pathological examination, and auxiliary examination can help in diagnosis and differential diagnosis:

(1) Gastroscopy and endoscopic ultrasonography generally show a single lesion, mostly located in the gastric antrum, which is a hemispherical and elliptical submucosal bulge with a complete and smooth surface mucosa

(2) Abdominal CT showed a round or oval mass.

(3) There is currently no detailed MRI imaging statistics for ectopic pancreas

(4) A round filling defect with smooth surface and clear edge can be seen on barium meal angiography of the gastrointestinal tract, and sometimes the so-called "central duct sign" or "umbilical depression" can be seen

Due to the rarity of ectopic pancreas, the lack of typical features in imaging examinations can easily lead to misdiagnosis

The reasons for the misdiagnosis in this case are as follows:

(1) The symptoms of ectopic pancreas are atypical and non-specific.

(2) The ectopic pancreas is mostly located in the submucosa, intraluminal growth is more common, and extraluminal growth is rare, and the rate of missed diagnosis and misdiagnosis is high.

(3) CT manifestations of atypical ectopic pancreas are often similar to those of normal pancreatic tissue

(4) Heterotopic pancreas generally grows slowly, but in this case, it grows rapidly, and it is difficult to differentiate from malignant tumors and misdiagnose