Case 80: splenosis

Spectrum of Heterotopic and Ectopic Splenic Conditions

A spectrum of heterotopic and ectopic splenic conditions may be encountered in clinical practice as incidental asymptomatic detection or symptomatic diagnosis. The radiologist needs to be aware of these conditions and their imaging characteristics to provide a prompt correct diagnosis and avoid misdiagnosis as neoplasm or lymphadenopathy. Having a strong knowledge base of the embryologic development of the spleen improves understanding of the pathophysiologic basis of these conditions. Spleen-specific imaging techniques-such as technetium 99m (99mTc)-labeled denatured erythrocyte scintigraphy, 99mTc-sulfur colloid liver-spleen scintigraphy, and MRI with ferumoxytol intravenous contrast material-can also be used to confirm the presence or absence of splenic tissue. Heterotopic splenic conditions include splenules and splenogonadal fusion (discontinuous or continuous forms). These heterotopic conditions are caused by incomplete fusion of the splenic primordia (splenule) and abnormal fusion of the gonadal and splenic tissue (splenogonadal fusion). Ectopic splenic conditions arise in patients with a prior splenic injury (splenosis), laxity or maldevelopment of the splenic ligaments (wandering spleen), or heterotaxy syndromes (polysplenia and asplenia). Importantly, these heterotopic and ectopic splenic conditions can also manifest with complications, including vascular torsion and rupture. ©RSNA, 2024.

The Benign Side of the Abdominal Wall: A Pictorial Review of Non-Neoplastic Diseases

The abdominal wall is the location of a wide spectrum of pathological conditions, from benign to malignant ones. Imaging is often recommended for the evaluation of known palpable abdominal masses. However, abdominal wall pathologies are often incidentally discovered and represent a clinical and diagnostic challenge. Knowledge of the possible etiologies and complications, combined with clinical history and laboratory findings, is crucial for the correct management of these conditions. Specific imaging clues can help the radiologist narrow the differential diagnosis and distinguish between malignant and benign processes. In this pictorial review, we will focus on the non-neoplastic benign masses and processes that can be encountered on the abdominal wall on cross-sectional imaging, with a particular focus on their management. Distinctive sonographic imaging clues, compared with computed tomography (CT) and magnetic resonance (MR) findings will be highlighted, together with clinical and practical tips for reaching the diagnosis and guiding patient management, to provide a complete diagnostic guide for the radiologist.

Abdominal and pelvic splenosis: atypical findings, pitfalls, and mimics

Splenosis is an acquired form of ectopic splenic tissue that typically arises after trauma or splenectomy. It is often an incidental image finding in an otherwise asymptomatic patient, but the spectrum of symptoms varies based on the site of implantation. Radiologists should be familiar with the imaging features of splenosis to avoid mistaking it for malignancy. Splenosis has identical imaging features to that of the native spleen on US, CT, MRI, and nuclear medicine examinations. Therefore, when the radiologic findings support the diagnosis of splenosis, the patient can be spared invasive procedures for tissue sampling.

Abdominal splenosis and its differential diagnoses: What the radiologist needs to know

Splenosis is a benign acquired condition characterized by the presence of heterotopic viable splenic tissue in other organs or within cavities such as peritoneum, retroperitoneum, or thorax after splenic trauma or surgery. Abdominal splenosis is often an incidental finding and computed tomography and magnetic resonance usually allow a confident diagnosis. The typical enhancement that parallels the spleen is a useful hallmark of splenosis. Splenic implants lack contrast uptake in the hepatobiliary phase and show high signal at high b-values on diffusion-weighted images. In some cases splenosis may mimic malignant and benign conditions in the peritoneum as well as in hollow and parenchymal abdominal organs and further investigations - including scintigraphy with Tc99m-labelled heat-denatured red blood cells or biopsy - are sometimes required in challenging cases. This pictorial essay reviews the imaging presentation and potential differential diagnosis of splenosis according to the site of implantation. A prompt and accurate radiological diagnosis of splenosis can avoid unnecessary biopsy or surgery.

Follicular lymphoma in a patient with splenosis: a case report

Splenosis refers to the seeding of splenic cells associated with surgery or trauma. Splenosis mimicking other diseases has been reported in the literature. To the best of our knowledge, this is the first case of follicular lymphoma in a patient with splenosis whose diagnosis of lymphoma was delayed because of a known history of splenosis. We report a 48-year-old male patient who underwent splenectomy because of injury from a high fall 20 years previously. He had no symptoms other than mild abdominal pain until 2 years previously, which was thought to be associated with splenosis. When his symptoms began to increase, he had explorative laparotomy for diagnosis, which was later confirmed as follicular lymphoma. Splenosis may delay the diagnosis of other conditions that can be underestimated. Clinicians should be aware of unusual symptoms in patients with splenosis.

Management of intrahepatic splenosis:a case report and review of the literature

Background

Splenosis is the heterotopic autotransplantation and implantation of splenic tissue after splenic trauma or splenectomy. Considering that splenosis often occurs in the mesentery, omentum, and peritoneum, intrahepatic splenosis has seldom been reported. We report a rare case of isolated intrahepatic splenosis in a 54-year-old man who presented with a liver mass thought to be hepatocellular carcinoma.

Case presentation

A 54-year-old man was referred to our hospital for further evaluation of a liver lesion. The patient was asymptomatic and had a history of emergent splenectomy after a high-altitude falling accident. Abdominal contrast-enhanced computed tomography revealed a 4.5 × 3.3 cm lesion that was located in segment IV of the left liver lobe. The lesion had an inhomogeneous enhancement during the arterial phase and diminished enhancement during the portal and equilibrium phases. Similar radiological features were also observed on a contrast magnetic resonance imaging scan. Partial hepatectomy was performed with the suspicion of hepatocellular carcinoma. Pathological examination of the liver specimen revealed intrahepatic splenosis.

Conclusion

Splenosis should be considered in differential diagnosis of a liver mass discovered years after splenic trauma or surgery. A proposed scoring system may be helpful in evaluating the suspicious degree of intrahepatic mass to be splenosis. Invasive treatments are not recommended for asymptomatic patients, since the splenosis can provide beneficial immunologic function.

Splenosis involving the gastric fundus, a rare cause of massive upper gastrointestinal bleeding: a case report and review of the literature

Splenosis, the autotransplantation of splenic tissue following splenic trauma, is uncommonly clinically significant. Splenosis is typically diagnosed incidentally on imaging or at laparotomy and has been mistakenly attributed to various malignancies and pathological conditions. On the rare occasion when splenosis plays a causative role in a pathological condition, a diagnostic challenge may ensue that can lead to a delay in both diagnosis and treatment. The following case report describes a patient presenting with a massive upper gastrointestinal bleed resulting from arterial enlargement within the gastric fundus secondary to perigastric splenosis. The cause of the bleeding was initially elusive and this case highlights the importance of a thorough clinical history when faced with a diagnostic challenge. Treatment options, including the successful use of transarterial embolization in this case, are also presented.

Laparoscopic gastric band removal complicated by splenosis

In any patient, the occurrence of postsplenectomy splenosis can complicate the planning of further surgeries. In our case, the gastric sleeve procedure was aborted, as it would have put the patient's life in danger. Therefore, only the gastric band was removed, eliminating future erosion.

Laparoscopic resection of isolated hepatic splenosis mimicking liver tumors: case report with a literature review

Isolated hepatic splenosis is a rare condition in hepatobiliary surgery. In this study, we report a case of this condition managed by laparoscopic surgery. A 38-year-old male hepatitis B virus carrier, who had a motorcycle accident and splenectomy 14 years before the current incident, was hospitalized due to a hepatic mass. His laboratory tests were consistent with a hyposplenic state, whereas radiologic images revealed a benign tumor in the left liver lobe located in a site difficult to access with preoperative biopsy. Therefore, we performed a laparoscopic exploration and total resection, which revealed a bluish oval encapsulated nodule in the narrow gap between the diaphragm, falciform ligament, and left hepatic capsule. The pathologic diagnosis was hepatic splenosis. Unlike other patients with multiple intraperitoneal lesions and relatively normal splenism, this is the first case of isolated hepatic splenosis with evident hyposplenism managed by laparoscopic approach in the English literature.

Early pancreatic splenosis presented 2 years after splenectomy

Splenosis is defined as the autotransplantation of splenic tissue resulting from the spillage of cells from the pulp of damaged spleen after splenic injury or splenectomy. The splenic tissue implants are generally numerous, and the preferred location is the grater omentum. Pancreatic splenosis is a rare condition with only two previous cases reported in the English literature. We describe a case of pancreatic splenosis with unusual characteristics, in which a definitive diagnosis was obtained with the use of (99m)Technetium-sulfur-colloid scintigraphy avoiding invasive procedures or surgical removal.

Hepatic spleen nodules (HSN)

Hepatic splenosis is a nodular implant of normal spleen tissue in the liver. This innocent liver nodule is frequently misinterpreted as a malignancy. Almost all hepatic splenoses have been associated with a clinical history of splenic trauma or prior surgery. This report describes two cases of hepatic splenosis. In both patients, the nodular lesions were initially thought to be liver malignancies and they were ultimately assessed by histology. The clinico-pathological findings of all published cases of liver splenosis underwent critical review. Although they are rare, hepatic spleen nodules should always be included in the diagnostic spectrum of nodular liver lesions because of their impact on treatment decisions.

Secondary tumors and tumorlike lesions of the peritoneal cavity: imaging features with pathologic correlation

Tumors and tumorlike lesions that secondarily involve the mesothelial or submesothelial layers of the peritoneum are a diverse group of disorders that range in biologic behavior from benign to highly malignant. The anatomy of peritoneal ligaments and mesenteries and the normal circulation of peritoneal fluid dictate location and distribution of these diseases within the peritoneal cavity. Peritoneal carcinomatosis is the most common secondary tumor to affect the peritoneal cavity. When it arises from carcinomas of the gastrointestinal tract or ovary, the prognosis is grave. However, when low-grade mucinous adenocarcinoma of the appendix spreads to the peritoneal cavity, the consequence is typically pseudomyxoma peritonei, which is a clinical syndrome, characterized by recurrent and recalcitrant voluminous mucinous ascites due to surface growth on the peritoneum without significant invasion of underlying tissues. Carcinomas from elsewhere in the body, as well as lymphomas and sarcomas, may also produce diffuse peritoneal metastasis. Granulomatous peritonitis is the consequence of disseminated infection such as tuberculosis or histoplasmosis, foreign materials, or rupture of a tumor or hollow viscus. Finally, a group of benign miscellaneous conditions that range from common disorders such as endometriosis and splenosis to very rare conditions such as gliomatosis peritonei and melanosis may also affect the peritoneum diffusely. Secondary tumors and tumorlike lesions of the peritoneum have overlapping imaging features when compared with each other and primary peritoneal tumors. Knowledge of peritoneal anatomy, normal fluid circulation within the peritoneal cavity, and clinical and pathologic features of secondary peritoneal lesions is essential for identification of these lesions.

Intrahepatic splenosis mimicking hepatoma

A 54-year-old man with a past history of splenectomy some 20 years previously presented with a hepatic mass. Subsequent histopathology revealed that the mass was due to intrahepatic splenosis. The presentation of this case is discussed together with a literature review of splenosis.

Hepatic splenosis preoperatively diagnosed as hepatocellular carcinoma in a patient with chronic hepatitis B: a case report

We report on a case of hepatic splenosis. A 32-yr-old man underwent a splenectomy due to trauma at the age of 6. He had been diagnosed as being a chronic hepatitis B-virus carrier 16 yr prior to the surgery. The dynamic computer tomography (CT) performed due to elevated serum alpha-fetoprotein (128 ng/mL) demonstrated two hepatic nodules, which were located near the liver capsule. A nodule in Segment IVa had a slight enhancement during both the arterial and portal phases, and another nodule in Segment VI showed a slight enhancement only in the portal phases. Dynamic magnetic resonance imaging (MRI) of the mass in Segment VI showed enhanced development in the arterial phases and slight hyperintensivity to the liver parenchyma in the portal phases. These imaging findings suggested a hypervascular tumor in the liver, which could be either focal nodular hyperplasia, adenoma, or hepatocellular carcinoma (HCC). Even though these lesions were diagnosed as HCC, some of the findings were not compatible with typical HCC. On dynamic CT and MRI, all lesions showed a slight arterial enhancement and did not show early venous washout. All lesions were located near the liver capsule. These findings, along with a history of splenectomy, suggested a diagnosis of hepatic splenosis.

A case of multiple intra-abdominal splenosis with computed tomography and magnetic resonance imaging correlative findings

Hepatic splenosis refers to heterotopic auto-transplantation and implantation of splenic tissue resulting from the spillage of cells from the spleen after splenic trauma or splenectomy. The true incidence of splenosis is unknown, because this entity is usually an incidental finding at surgery. Splenic implants are usually multiple, and can be localized anywhere in the peritoneal cavity. Splenic implants in the peritoneal cavity may be confused with renal tumors, abdominal lymphomas and endometriosis. We describe computed tomography (CT) and magnetic resonance imaging (MRI) findings in a rare case of multiple intra-abdominal splenosis located along the hepatic surface and adjacent to the upper pole of the right kidney, mimicking a renal neoplasm.

Hypervascular hepatic focal lesions: spectrum of imaging features

Detection and characterization of liver lesions often present a diagnostic challenge to the radiologists. Liver lesions may be classified as hypovascular and hypervascular based on degree of hepatic arterial blood supply. Common hypervascular liver lesions include hemangioma, focal nodular hyperplasia, hepatocellular adenoma, hepatocellular carcinoma, fibrolamellar carcinoma, and metastases from primary tumors such as islet cell tumor, carcinoid, renal cell carcinoma, melanoma, and thyroid carcinoma. In this review article, we discuss the spectrum of imaging features of hypervascular liver lesions.

Imagerie hépatique : pièges, pseudolésions et pseudotumeurs

Recognition of pseudolesions of the liver at imaging is important because of their close resemblance to primary liver cancer or metastases. There are several types of pseudolesions: pseudolesions, with mostly straight borders, corresponding to perfusion abnormalities, fatty liver, confluent fibrosis and radiation hepatitis; morphologic changes of the liver; true pseudotumors. The use of multidetector CT and MR imaging increases the likelihood of detecting such lesions in routine practice. Radiologists must recognize these lesions and understand the underlying etiology.

Single-Photon Emission Computed Tomography/Computed Tomography in Abdominal Diseases

Single-photon emission computed tomography (SPECT) studies of the abdominal region are established in conventional nuclear medicine because of their easy and large availability, even in the most peripheral hospitals. It is well known that SPECT imaging demonstrates function, rather than anatomy. It is useful in the diagnosis of various disorders because of its ability to detect changes caused by disease before identifiable anatomic correlates and clinical manifestations exist. However, SPECT data frequently need anatomic landmarks to precisely depict the site of a focus of abnormal tracer uptake and the structures containing normal activity; the fusion with morphological studies can furnish an anatomical map to scintigraphic findings. In the past, software-based fusion of independently performed SPECT and CT or magnetic resonance images have been demonstrated to be time consuming and not useful for routine clinical employment. The recent development of dual-modality integrated imaging systems, which provide SPECT and CT images in the same scanning session, with the acquired images co-registered by means of the hardware, has created a new scenario. The first data have been mainly reported in oncology patients and indicate that SPECT/CT is very useful because it is able to provide further information of clinical value in several cases. In SPECT studies of abdominal diseases, hybrid SPECT/CT can play a role in the differential diagnosis of hepatic hemangiomas located near vascular structures, in precisely detecting and localizing active splenic tissue caused by splenosis in splenectomy patients, in providing important information for therapy optimization in patients submitted to hepatic arterial perfusion scintigraphy, in accurately identifying the involved bowel segments in patients with inflammatory bowel diseases, and in correctly localizing the bleeding sites in patients with gastrointestinal bleeding.