Radiological features of a symptomatic splenic hamartoma

Splenic hamartomas in children

Splenic hamartomas (SHs) are uncommon, benign vascular lesions of unclear etiology and are mostly found incidentally on abdominal images, at surgery, or at autopsy. Since the first case description, in 1861, less than 50 pediatric SH cases have been reported in the literature. In this article, we have performed an analysis of all SH cases in children published in the literature to date and presented our case of an 8-year-old male with SH. These lesions in children were shown to cause symptoms more often than in the adult population. The observed SH sizes in children ranged from a few millimeters to 18 cm, and the symptomatic lesions were mostly larger or multiple. The most common clinical finding was splenomegaly. Signs of hypersplenism were present in children with a single SH larger than 4.5 cm (diameter range: 4.5-18.0 cm) and in those with multiple hamartomas, ranging from a few millimeters to 5 cm. Eighty percent of patients with available laboratory findings had hematological abnormalities such as anemia, thrombocytopenia, or pancytopenia. Other symptoms and signs included abdominal pain, recurrent infections, fever, night sweats, lethargy, growth retardation, and weight loss. The use of multiple imaging modalities may suggest the preoperative diagnosis of a splenic mass in children and determine the therapeutic approach. However, the final diagnosis of SH relies on histopathological evaluation. Surgery, including total or partial splenectomy (PS), is the mainstay of SH management. Although total splenectomy carries a greater risk of overwhelming post-splenectomy infection than PS it has remained the most performed surgical procedure in children with SH. In the majority of pediatric patients with symptomatic SH, resolution of symptoms and resolution or improvement of cytopenias occurred after surgical treatment.

Revisiting the Spleen—An Imaging Review of the Common and Uncommon Splenic Pathology

The spleen is the largest lymphatic organ and is responsible for both hematological and immunological functions. Several common etiologies such as trauma, developmental variants, infectious/inflammatory conditions, and benign and malignant lesions can occur in the spleen. The role of imaging modalities such as ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) in diagnosing these conditions continues to evolve. The main objective of this review article is to illustrate the role of imaging in identifying the common and uncommon pathology of the spleen.

Multi-modality imaging findings of splenic hamartoma: a report of nine cases and review of the literature

PURPOSE

To investigate the presentation of splenic hamartomas (SHs) on ultrasonography (US), CT and MRI.

METHODS

Nine patients (5 males and 4 females, mean age, 52.8 years) with pathologically proven SHs were included in this study. US, CT and MRI images were analyzed retrospectively, and imaging features were correlated with pathological findings.

RESULTS

SHs appeared solitary lesion (n = 8) and multiple lesions (n = 1) in the present study. (1) In 8 cases of solitary lesion, the lesions appeared as solid nodules or masses with well-defined margins and varying echogenicity (hyperecho = 5, hypoecho = 2, strong echo = 1) on ultrasound. The lesions showed iso-attenuation (n = 3) or slightly hypo-attenuation (n = 4) on unenhanced CT, and calcification were revealed in 3 lesions. MRI showed isointensity (n = 3) or hypointensity (n = 2) on the T1-weighted image, and heterogeneous hypointensity (n = 2), slightly hyperintensity (n = 2) and hyperintensity (n = 1) on the T2-weighted image. The enhanced patterns of SHs showed mild diffuse heterogeneous enhancement (n = 6) and prominent enhancement (n = 1) during arterial phase and above 7 lesions were demonstrated progressive enhancement at delayed phase on enhanced CT. One lesion without any enhancement was revealed in another patient. (2) One case of multiple lesions included 1 cystic lesion with irregular calcification and 7 solid lesions with progressive enhancement on CT images.

CONCLUSIONS

Combination of a variety of imaging modalities could more fully reflect the pathological characteristics and contribute to the diagnosis of SH.

Superparamagnetic iron oxide-enhanced magnetic resonance imaging in a case of spleen hamartoma

OBJECTIVE

To emphasize the contribution of superparamagnetic iron oxide (SPIO) contrast agent in the diagnosis of the splenic hamartoma.

CLINICAL PRESENTATION AND INTERVENTION

A 63-year-old female was admitted to our hospital with diffuse abdominal pain. An ultrasound examination revealed a 5 × 4 cm solid lesion in the spleen. Dynamic gadolinium-enhanced magnetic resonance imaging (MRI) of the abdominal findings was consistent with a splenic hamartoma. SPIO-enhanced MRI was then performed and it confirmed the diagnosis. The lesion showed a decrease of signal intensity on T2-weighted images.

CONCLUSION

This case showed that SPIO-enhanced MRI was useful for establishing a noninvasive diagnosis of the splenic hamartomas.

Computed tomography of the spleen: how to interpret the hypodense lesion

Background

As the largest single lymphatic organ in the human body, the spleen is responsible for central immunological and haematological tasks. Therefore, the spleen can be subject to a wide range of pathologic disorders. Computed tomography (CT) represents the most widely applied cross-sectional abdominal imaging technique and is considered the imaging modality of choice for the evaluation of numerous abdominal pathological conditions. Hypodense splenic lesions are frequently encountered on abdominal CT images. Although most hypodense lesions of the spleen can be considered benign, some findings and clinical conditions warrant closer attention to the lesion. CT offers a number of morphological criteria that can be applied to differentiate hypodense lesions of the spleen, such as a the appearance of a lesion’s borders, its attenuation, as well as the presence of calcifications or solid components.

Methods

This article reviews the most common splenic pathologies leading to hypodense appearances on CT images and illustrates the key CT imaging findings in the context of the clinical history of the patients.

Conclusion

The key imaging findings of hypodense splenic lesions are presented in order to aid interpretation during routine evaluation of abdominal CT images.

Teaching Points

• Haemangiomas, congenital in origin, represent the most common benign lesions of the spleen.

• Lymphoma represents the most common malignant tumour of the, usually secondarily involved, spleen.

• Most hypodense splenic lesions on CT represent benign lesions that require no further work-up.

• For correct interpretation, hypodense splenic lesions need to be evaluated in the clinical context.

Splenic hamartoma: a case report and clinicopathological analysis of Japanese cases

A 75-year-old man was referred to our department for the treatment of a gastric submucosal tumor-like protrusion which had gradually enlarged over 3 years. After examination with various types of imaging modalities, a splenic mass was diagnosed. Splenectomy was performed because it was difficult to determine preoperatively whether the splenic mass was benign or malignant. The postoperative pathological examination revealed a splenic hamartoma without malignancy. Despite the preoperative examination with advanced diagnostic imaging techniques and equipment, an accurate diagnosis of splenic hamartoma is difficult due to its rarity, lack of specific symptoms, and various inadequacies of radiological imaging techniques. Here we present a rare case of splenic hamartoma and discuss the clinical characteristics obtained from a review of Japanese cases of this rare condition.

Gastrointestinal tumors in children

Although tumors arising from the spleen, pancreas, and gastrointestinal tract in the pediatric population are relatively uncommon, imaging plays an important role in diagnosis, staging, and treatment planning. Initial imaging with abdominal radiograph contributes to the evaluation for intestinal obstruction, constipation, and mass effect, and sometimes may reveal areas of calcification.

Solitary splenic lesions

Solitary splenic lesions are unusual. A differential diagnosis can be organized around their basic imaging appearance as either predominantly cystic or solid. Other imaging characteristics, including vascular enhancement and activity on Tc-99m sulfur colloid scan, as well as clinical history may narrow the diagnostic possibilities. Cystic lesions include post-traumatic, inflammatory and infectious pseudocysts, congenital cysts, lymphangiomas and cystic metastasis. Solid lesions include both nonneoplastic lesions such as splenic hamartoma, benign tumors such as hemangioma and malignant masses including lymphoma and angiosarcoma. Percutaneous biopsy may be used for histologic diagnosis when required.

MR imaging of the spleen: spectrum of abnormalities

The spleen has the same relationship to the circulatory system that the lymph nodes have to the lymphatic system. A wide range of diseases can affect the spleen. Pathologic conditions of the spleen can be classified into the following categories: congenital diseases (accessory spleen, polysplenia, and asplenia); trauma; inflammation (abscess, candidiasis, histoplasmosis, and sarcoidosis); vascular disorders (infarction, diseases affecting the splenic vasculature, and arteriovenous malformation); hematologic disorders (sickle cell disease and extramedullary hematopoiesis); benign tumors (cysts, hemangioma, diffuse hemangiomatosis of the spleen, and hamartoma); malignant tumors (sarcoma, lymphoma, and metastases); and other disease processes that affect the spleen diffusely (portal hypertension, Gaucher disease, and sickle cell disease) or focally (Gamna-Gandy nodules). New magnetic resonance (MR) imaging techniques have increased the role of MR imaging in detection and characterization of splenic diseases. MR imaging is an excellent tool for diagnosis and evaluation of focal lesions and pathologic conditions of the spleen.

Splenic hamartoma: presentation on contrast-enhanced sonography

Splenic hamartoma is a rare benign tumor of the spleen. It is usually found incidentally at autopsy or splenectomy. We report a case of splenic hamartoma that was discovered during medical workup for vague upper abdominal pain. Abdominal sonography demonstrated a well-demarcated, slightly hypoechoic splenic solid mass; the mass was markedly enhanced on color Doppler sonography after injection of microbubble contrast agent. This finding may help to distinguish splenic hamartomas from other relatively common splenic tumors, such as hemangiomas or metastases.

Imaging findings of splenic hamartoma

AIM: To assess CT and MR manifestations and their diagnostic value in splenic hamartoma with review of literatures.

METHODS: We described a woman who was accidentally found to have a splenic tumor by ultrasound of the abdomen. CT and MR findings of this splenic hamartoma were proved by pathology retrospectively.

RESULTS: The CT and MR findings in this case included a ball-like mass with homogeneous mild-hypodensity lesions on non-enhanced CT scans or isointensity on T₁-weighted images and mild hypointensity on T₂-weighted images, progressive homogeneous enhancement on multiple-phase spiral CT and MR enhanced scans, and isodense enhancement on delayed post-contrast CT scans and obvious hyperintensity relative to the spleen on delayed MR images.

CONCLUSION: Splenic hamartoma has some specific radiological features. However, the diagnosis of this disease must be based on clinical features and confirmed by pathology.

From the Archives of the AFIP

Primary vascular neoplasms of the spleen constitute the majority of nonhematolymphoid splenic tumors. The benign primary vascular tumors include hemangioma, hamartoma, and lymphangioma, whereas those of variable or uncertain biologic behavior include littoral cell angioma, hemangioendothelioma, and hemangiopericytoma. The primary malignant vascular neoplasm of the spleen is angiosarcoma. Peliosis is a rare lesion of unknown cause that is usually found incidentally in asymptomatic patients but may be associated with hematologic or metastatic disease. Although these vascular neoplasms of the spleen are uncommon, their importance lies in that they must be differentiated from the more common neoplastic disorders of the spleen, such as lymphoma and metastasis. The most common echogenic solid or complex cystic mass in an asymptomatic patient is splenic hemangioma. However, the imaging appearance of splenic hemangiomas may be complex, and differentiation of these lesions from malignant disease may not be possible. The diagnosis of splenic hamartoma may be suggested when findings of increased blood flow on color Doppler images are seen in association with a homogeneous solid echogenic mass. A large subcapsular solitary cystic abnormality discovered incidentally in a child in association with internal septations and tiny mural nodules favors the diagnosis of lymphangioma. Any invasion of the surrounding splenic parenchyma by a splenic lesion should indicate a more aggressive or malignant process. Evaluation of a focal splenic abnormality identified on sonograms should be followed up with computed tomography or magnetic resonance imaging with and without contrast material enhancement. Splenectomy may be required for definitive evaluation of a splenic mass with atypical features.

"Hamartoma" of the spleen (splenoma) in children

Hamartomas of the spleen or splenomas, are uncommon benign tumorous growths in this organ which have not been well characterized in children. We report four patients, 4 to 11 years old, who had splenomegaly and splenic "hamartomas" associated with different hematologic conditions (refractory microcytic anemia, sickle cell anemia, hereditary spherocytosis, and dyserythropoietic hemolytic anemia). All patients had total splenectomy as a primary therapeutic approach or to lessen their transfusion requirements. In only one patient was a focal splenic mass identified preoperatively with contrasted computed tomography (CT) scans and magnetic resonance imaging (MRI). None of the patients showed a mass by ultrasonography. Gross examination showed enlarged spleens (315-724 g) which on cut surface revealed a single nodule in one and multiple bulging nodules in three specimens. The nodules varied from 1.3 to 7 cm and were indistinct from the surrounding nonlymphoid splenic (i.e., red pulp) parenchyma. Histology of the nodules showed red splenic pulp with variable histiocytic proliferation, focal extramedullary hematopoiesis, lympho-plasmacytosis, fibrosis, and siderotic-calcific deposits. Intranodular small T- and B-cell lymphoid aggregates but no organized secondary follicles or periarteriolar sheaths were seen. Proliferation antigen Ki-67 (Mib-1) immunostains showed a low (< 5%) proliferation index in the nodules and surrounding tissue. Reticulin stains did not show a capsule or border between the normal spleen and the nodules. The critical histologic differential diagnosis for these lesions is with benign vascular tumors. These can be identified by their more disorderly pattern, by immunohistochemistry and by their higher proliferation index. It is our contention that these splenic nodules are not true hamartomas, as they seem to result from remote ischemic or infectious/inflammatory insults, leading to the fibro-inflammatory reaction and deposition of calcium and hemosiderin that is better designated with the descriptive term of splenoma. Review of the literature and our own experience indicates that most children with splenic hamartomas or splenomas as we prefer to call them, have an underlying hematologic disorder likely made worse by a state of hypersplenism that explains the consistent improvement in the blood values after splenectomy.

Splenic vascular lesions: unusual features and a review of the literature

Hamartoma and peliosis are uncommon splenic lesions. Approximately 120 splenic hamartomas and 40 splenic peliosis have been reported in the English literature. In the present study, a unique case of multiple splenic hamartomas with peliosis was reported. The splenic lesions were incidental findings in a 36-year-old man with ruptured sarcomatoid renal cell carcinoma. They were diagnosed clinically as metastatic renal cell carcinoma. On pathological examination, peliosis was noted in the splenic hamartomas as well as in the splenic parenchyma. In addition, the clinicopathological features of five other splenic hamartomas (including one giant hamartoma) noted in our department were presented. A re-evaluation of the features of the splenic hamartomas documented in the English literature was also done.

Symptomatic splenic hamartoma: case report and literature review

An 11-year-old girl with low-grade fever, night sweats, thrombocytopenia, and an 8-year history of progressive splenomegaly underwent an elective splenectomy. Pathologic diagnosis was multiple splenic hamartoma. The patient's symptoms resolved after the splenectomy. Since first described by Rokitansky in 1861, approximately 140 cases of splenic hamartoma have been described in the literature. Most of the splenic hamartomas were discovered incidentally. A minority of these lesions were associated with hematologic symptoms such as pancytopenia, anemia, and thrombocytopenia. Only 20 of the reported cases of splenic hamartoma occurred in pediatric patients. However, compared with the adult patients, nearly half of these cases in pediatric patients was associated with symptoms. Splenectomy and partial splenectomy have relieved these symptoms. With advances in imaging, splenic hamartomas are being discovered with increasing frequency. A multimodal radiologic work-up has enabled some cases of splenic hamartoma to be diagnosed preoperatively. Inclusion of this benign entity in the differential diagnoses of symptomatic splenomegaly in a pediatric patient is important in the preoperative management and counseling of the patient and family. In patients who have discrete lesions, consideration of this entity preoperatively may avoid total splenectomy.