Accessory spleen located in the right parietal peritoneum: The first case report

Abstract

Rationale: Accessory spleen is a congenital abnormality caused by failure of the splenic anlage to fuse during embryology. The presence of an accessory spleen located in the parietal peritoneum has not been reported so far, and an accessory spleen situated on the right side is extremely rare. In the present study, we describe the first case of an accessory spleen located in the right parietal peritoneum.

Patients concerns: A 65-year-old man, presented with pain in his left abdomen for 1 month.

Diagnoses: With ultrasonography and computed tomography, it was difficult to determine the accurate location and diagnosis, and an abdominal fibroma was preoperatively considered.

Interventions: By laparotomy, we found a mass connected to the right parietal peritoneum by a vascular pedicle. We resected it completely, and the gross specimen measured 5.0 × 3.0 × 2.5 cm and was a localized tumor with a capsule.

Outcomes: Microscopically, sinusoids were visible, as well as scattered lymphoid follicles, eosinophils, histiocytes, plasma cells, neutrophils, and red blood cells, indicative of splenic tissue. Finally, the lesion was diagnosed as an accessory spleen located in the right parietal peritoneum. Postoperatively, he recovered well and was followed up for a 31 months, during which he was well with no complication.

Lessons: We present the first accessory spleen located in the right parietal peritoneum. Awareness of the accessory spleen and familiarity with typical imaging findings are necessary for surgeons to make a precise preoperative diagnosis.

Figure 1

Ultrasongram showing a 4.4 × 2.6 cm, well-defined solid mass (arrow) in the middle upper quadrant of the right abdominal cavity.

Figure 2

An unenhanced computed tomography (CT) scan showing a well-defined homogeneous mass (arrow) in the area corresponding to the right liver, abdominal wall, and colon, measuring 4.9 × 3.0 cm (A). On the contrast-enhanced CT scan, the mass (arrow) is homogeneously enhanced (B).

Figure 3

Histopathological examination showing that the mass is enclosed by a fibrous capsule (arrow) (A) (HE ×50). Sinusoids, scattered lymphoid follicles, eosinophils, histiocytes, plasma cells, neutrophils, and red blood cells are visible (B) (HE ×100). HE = hematoxylin and eosin.