Diffuse Abdominal Splenosis Mimicking Peritoneal Metastases in a 35-Year-Old Man with a Resectable Carcinoma of the Ampulla of Vater
A 35-year-old man had suffered from intermittent upper abdominal pain for approximately 1 month. An ultrasound of the abdomen revealed no pathology, and routine blood tests were normal apart from an elevated P-amylase of 374 U/l (approx. twice the upper normal limit). At elective gastroscopy 3 weeks later, the patient reported increasing fatigue and an unintended weight loss of 7 kg. On clinical examination, he was icteric. His bilirubin was 105 μmol/l (normal range 5–25 μmol/l), ALAT was 621 U/l (normal range 10–70 U/l) and alkaline phosphatase was 430 U/l (normal range 35–105 U/l). Slight anemia of 7.2 mmol/l (normal range 8.3–10.5 mmol/l) and thrombocytosis of 424 × 109/l (normal range 145–350 × 109/l) were also found. The patient's medical report included splenectomy following a motocross accident with blunt abdominal trauma and intra-abdominal bleeding 20 years earlier, and surgery for appendicitis the same year.\nThe gastroduodenoscopy showed a macroscopically malignant tumor located between the first and second part of the duodenum, involving almost the entire lumen. Biopsies showed an invasive, poorly differentiated adenocarcinoma of the intestinal type. A CT scan with intravenous and peroral contrast (fig. ) revealed a tumor in the ampulla (arrow) involving the whole circumference of the duodenal lumen, but with no apparent involvement of major blood vessels or surrounding organs. In addition, multiple nodular tumors were seen in several intra-abdominal locations, giving rise to the suspicion of peritoneal metastases (fig. ). The nodules varied in size from a few millimeters up to 60 mm (A arrows). Surgical clips from the patient's prior splenectomy were also seen (B arrow). After these findings, the patient was referred to the multidisciplinary team conference for discussion of palliative chemotherapy.\nAt the multidisciplinary team conference, the patient's medical history and signs of previous surgery, including absence of the spleen and presence of multiple surgical clips in the abdominal wall, as well as the uncharacteristic appearance of the intra-abdominal lesions, raised the suspicion of diffuse posttraumatic splenosis. In support of this diagnosis, the CT scan showed slightly hypervascular lesions, with soft tissue attenuation and homogeneous enhancement in the portal venous phase. A core needle biopsy of 1 lesion showed characteristic morphological and immunohistological appearances of benign ectopic splenic tissue.\nA radical pancreaticoduodenectomy ad modum Whipple was performed following laparoscopy. The presence of splenosis was confirmed macroscopically and with frozen biopsies during surgery. The resected tumor was a poorly differentiated adenocarcinoma, originating from the papilla of Vater, with intravascular and perineural growth. Two of 22 lymph nodes contained metastatic adenocarcinoma. The TNM stage was pT2 pN1 M0 R0.\nThe postoperative CA 19-9 was normal (2.4 IU/l). After discussing the option with the patient, adjuvant treatment was offered consisting of gemcitabine 1,000 mg/m2, 3 weeks on, 1 week off, for 6 months. He tolerated the treatment well and is without any signs of recurrence at follow-up, 18 months after surgery.