Accessory spleen torsion: a rare cause of acute abdominal pain

Accessory spleens, which are also known as a splenunculus or a splenule, are a benign developmental anomaly in which nodules of splenic tissue exist separate to the main body of the spleen. It is a reasonably common phenomenon which is present in approximately 10-30% of the population, however they only infrequently become symptomatic. Torsion of an accessory spleen is a rare cause of abdominal pain with few cases reported in the literature, most commonly in the paediatric population. Without treatment, torsion can lead to significant complications including haemorrhagic shock, peritonitis or rupture. The rarity portends a diagnostic challenge and thus a high index of suspicion is crucial for attaining a prompt diagnosis and timely management. This case gives an account of a 43-year-old female who presented with abdominal pain secondary to a torted accessory spleen.

Impact of PET data driven respiratory motion correction and BSREM reconstruction of 68Ga-DOTATATE PET/CT for differentiating neuroendocrine tumors (NET) and intrapancreatic accessory spleens (IPAS)

To evaluate whether quantitative PET parameters of motion-corrected 68Ga-DOTATATE PET/CT can differentiate between intrapancreatic accessory spleens (IPAS) and pancreatic neuroendocrine tumor (pNET). A total of 498 consecutive patients with neuroendocrine tumors (NET) who underwent 68Ga-DOTATATE PET/CT between March 2017 and July 2019 were retrospectively analyzed. Subjects with accessory spleens (n = 43, thereof 7 IPAS) and pNET (n = 9) were included, resulting in a total of 45 scans. PET images were reconstructed using ordered-subsets expectation maximization (OSEM) and a fully convergent iterative image reconstruction algorithm with β-values of 1000 (BSREM1000). A data-driven gating (DDG) technique (MOTIONFREE, GE Healthcare) was applied to extract respiratory triggers and use them for PET motion correction within both reconstructions. PET parameters among different samples were compared using non-parametric tests. Receiver operating characteristics (ROC) analyzed the ability of PET parameters to differentiate IPAS and pNETs. SUVmax was able to distinguish pNET from accessory spleens and IPAs in BSREM1000 reconstructions (p < 0.05). This result was more reliable using DDG-based motion correction (p < 0.003) and was achieved in both OSEM and BSREM1000 reconstructions. For differentiating accessory spleens and pNETs with specificity 100%, the ROC analysis yielded an AUC of 0.742 (sensitivity 56%)/0.765 (sensitivity 56%)/0.846 (sensitivity 62%)/0.840 (sensitivity 63%) for SUVmax 36.7/41.9/36.9/41.7 in OSEM/BSREM1000/OSEM + DDG/BSREM1000 + DDG, respectively. BSREM1000 + DDG can accurately differentiate pNET from accessory spleen. Both BSREM1000 and DDG lead to a significant SUV increase compared to OSEM and non-motion-corrected data.

Accessory sple­en in a dog: Macroscopic and microscopic findings

Accessory spleens are one or more areas of normal ectopic splenic tissue of variable size supplied by the branches of the splenic artery. A 7 year-old mixed breed male dog was fixed for use as a model in anatomy hall. During the abdominal dissection, the gross examination showed a 6.3×3.1×1 cm mass that was situated on the caudodorsal border of the spleen. Its appearance and firm consistency were similar to those of spleen. There was no connection between the spleen and this mass. It was supplied by accessory splenic artery. Microscopic examination of the mass revealed some structures similar to spleen.

Spleno-adrenal fusion mimicking an adrenal metastasis of a renal cell carcinoma: A case report and embryological background

Foci of splenic tissue separated from the spleen can occur as a congenital anomaly. Isolated nodules of splenic tissue are called accessory spleens or spleniculli. However, nodules of splenic tissue can merge with other organs during embryonic development, in which case we speak of spleno-visceral fusions: most often, they merge with the tail of the pancreas (thus forming spleno-pancreatic fusion or an intrapancreatic accessory spleen), with the reproductive gland (i.e., spleno-gonadal fusion), or with the kidney (i.e., spleno-renal fusion). Our case report describes the fusion of heterotopic splenic tissue with the right adrenal gland, which was misinterpreted as a metastasis of a renal cell carcinoma. To the best of our knowledge, this is the first reported case of spleno-adrenal fusion. Spleno-visceral fusions usually represent asymptomatic conditions; their main clinical significance lies in the confusion they cause and its misinterpretation as tumors of other organs. We believe that the cause of retroperitoneal spleno-visceral fusions is the anomalous migration of splenic cells along the dorsal mesentery to the urogenital ridge, together with primitive germ cells, at the end of the fifth week and during the sixth week of embryonic age. This theory explains the possible origin of spleno-visceral fusions, their different frequency of occurrence, and the predominance of findings on the left side.

Laparoscopic Resection of a Left Upper Quadrant Mass Leading to a Surprise Diagnosis

Background. Resplenectomy is most commonly done for the treatment of recurrent idiopathic thrombocytopenic purpura (ITP) refractory to medical management due to the regrowth of a missed accessory spleen. Case Report. A 66-year-old male had undergone open splenectomy for traumatic rupture 40 years ago. He presented with a leiomyosarcoma of his leg, which was surgically removed. When he developed metastatic disease, chemotherapy was started. He developed left upper quadrant pain, and on CT scan, a 5 cm mass compatible with a sarcoma was found between the tail of the pancreas and the left adrenal gland. During laparoscopy, dense adhesion of the omentum to the abdominal wall and the stomach from his previous splenectomy was divided. The lesser sac was opened through the gastrocolic ligament, and the splenic flexure was taken down. Superior and dorsal to the tail of the pancreas next to the left adrenal gland, the mass was identified and carefully dissected out. The vascular pedicle, which originated from a side branch of the splenic vessels at the tail of the pancreas, was stapled. The gastric fundus showed multiple nodules, and therefore, a modified sleeve gastrectomy was done; also, a 2 cm nodule in segment 5 of the liver and an omental nodule were removed. The tumors and gastrectomy specimen were placed in an endobag and removed through a periumbilical mini-incision. The patient recovered without any complications from the procedure and his LUQ pain resolved. Pathology revealed no sarcoma metastases but accessory spleens in all specimens. Discussion. Splenosis with multiple implants within the abdomen after splenectomy for trauma is a rare condition. In our patient, this seems to have been triggered by chemotherapy for his sarcoma resulting in extramedullary hemopoiesis. Laparoscopic removal of accessory spleens can be safely done.

Spleen

The spleen develops from mesoderm during the fifth week of gestation. Eighty-five percent of humans have 1 spleen, and 15% have accessory spleens. The spleen cleans the blood by trapping and breaking down dysfunctional or old red blood cells. Splenic problems most commonly arise with trauma, lymphoma, benign cysts, and hematologic disorders. Surgeons evaluate the spleen using plain radiography (CXR; kidney, ureter, bladder), CT, MRI, angiography, and nuclear studies. Open splenectomy for trauma or splenomegaly is at times dangerous and difficult with the need for speed, blood transfusion, and hemodynamic support. Potential early postoperative complications include abscess, pancreatic injury, pneumonia, and wound infection.

Epidermoid Cyst within an Intrapancreatic Accessory Spleen Mimicking a Pancreatic Cystic Neoplasm

Although intra-abdominal accessory spleens are commonly found in 10-30% of the general population, epidermoid cyst within an intrapancreatic accessory spleen (ECIPAS) is an extremely rare entity and is often misdiagnosed preoperatively as a cystic malignancy. We present the case of a 51-year-old man who was referred to our clinic because of an incidentally found pancreatic tail cystic mass. Due to CA 19-9 level over 2000 and high suspicion of malignancy, the patient underwent distal pancreatectomy with splenectomy. Histopathological analysis revealed a squamous epithelial lining with splenic parenchyma within the cyst wall, which was consistent with ECIPAS. The patient was discharged on postoperative day 4 without any complication. As this disease may mimic malignancy with no characteristic features in preoperative imaging, it should be considered in the differential diagnosis of pancreatic cystic lesions.

Intrapancreatic accessory spleen mimicking malignant tumor: three case reports

Intrapancreatic hypervascular lesions may represent metastases, neuroendocrine tumors, or intrapancreatic accessory spleens. The benign intrapancreatic accessory spleen can be difficult to separate from a malignant neuroendocrine tumor or metastasis. We report three cases of pancreatic lesions that underwent pancreatic surgery due to suspicion of malignancy on imaging; all cases were histologically intrapancreatic accessory spleens. Our cases point to the importance of performing single-photon emission computed tomography with heat-damaged Tc-99m-pertechnetate labelled erythrocytes to identify splenic tissue, even though small lesions can show a false-negative result.