Multimodality imaging findings in image-guided biopsy proven splenic littoral cell angioma: series of three cases

Littoral cell angiomas: Benign lesion with a penchant for visceral malignancies

Littoral cell angiomas are rare vascular tumors of the spleen. Because of their rarity, unclear etiopathogenesis, and association with other malignancies, these tumors can pose diagnostic and therapeutic challenges. Due to paucity of published literature on this entity often limited to case reports, relevant data on this topic were procured and synthesized with the aid of a comprehensive Medline search in addition to oncologic, pathologic, radiologic, and surgical literature review on littoral cell angiomas. This article provides an in-depth review into postulated etiopathogenesis, pathology, clinical manifestations, associated malignancies, and prognostic features of littoral cell angiomas.

Incidental littoral cell angioma of the spleen: cross-sectional imaging findings and review of the literature

Littoral cell angioma (LCA) is a primary splenic hemangioma found mostly in normal red sinus shore cells of the reticuloendothelial cell system of the spleen. In most cases is benign, but sometimes malignancies have been reported. This tumor displayed epithelial and histiocytic properties based on its cell of origin, splenic littoral cells. In this case report, we will describe a case of a 21-year-male presenting with an incidentally discovered LCA illustrated by cross-sectional imaging techniques, highlighting how the diffusional sequence and the positron emission tomography study, thanks to their greater specificity, have contributed to reaching a correct diagnostic orientation more than dynamic studies with contrast agent in both computed tomography and magnetic resonance.

Algorithmic Approach to the Splenic Lesion Based on Radiologic-Pathologic Correlation

Splenic lesions are commonly discovered incidentally at imaging, without clinical signs or symptoms that may aid in diagnosis. As such, the differential diagnosis and subsequent management are based primarily on imaging characteristics. Much has been written about the myriad pathologic conditions that can occur in the spleen; however, there is little guidance on the approach to an incidental splenic mass. Applying an approach frequently used in imaging to the splenic mass-based on the number and consistency of lesions and refined by supplementary imaging features-allows formulation of a useful differential diagnosis. Solitary cystic masses include true cysts, pseudocysts, and parasitic cysts. When multiple cystic lesions are present, the differential diagnosis expands to include infectious lesions (abscess or microabscesses) and lymphangioma (a benign cystic neoplasm). Hemangioma is the most common solitary solid mass, although other vascular lesions (hamartoma, sclerosing angiomatoid nodular transformation) and nonvascular lesions (inflammatory pseudotumor, lymphoma) manifest as solitary and solid. When multiple solid masses are present, diffuse inflammatory disease (sarcoidosis), littoral cell angioma, and lymphoma should be considered. Malignancies, such as angiosarcoma or metastasis, can manifest as solitary or multiple and solid or cystic masses but are typically associated with symptoms or widespread primary malignancy. Careful assessment of the multimodality imaging characteristics of splenic lesions based on this approach aids the radiologist faced with the incidental splenic lesion. Online supplemental material is available for this article. Work of the U.S. Government published under an exclusive license with the RSNA.

Clinical Landscape of Littoral Cell Angioma in the Spleen Based on a Comprehensive Analysis

Objective

Littoral cell angioma (LCA) is currently considered to be a rare splenic tumor with malignant potential. As the epidemiology, pathogenesis, clinical manifestation, treatment, and prognosis remain unclear, the clinical diagnosis and treatment of LCA have not been standardized. Hence, we performed a comprehensive analysis of 189 observational studies comprising 435 patients to improve the current status of diagnosis and treatment.

Methods

PubMed, Embase, WanFang and CNKI were searched from inception to May 2021 to identify LCA studies that were published in English and Chinese. The clinical information of LCA patients were extracted and analyzed.

Results

The LCA has a male-to-female ratio of 0.90 and a solitary-to-multiple ratio of 0.31. In terms of clinical features, 69.7% of the patients showed splenomegaly, 49.7% were asymptomatic, and 39.2% experienced epigastric discomfort. As the imaging findings of patients with LCA were nonspecific, an image-guided biopsy (10/12) was a safe and effective method for diagnosing in this condition. Notably, results of the prognostic analysis indicated that LCA has a lower risk of recurrence and metastasis. The patient may develop a stable disease or the tumor will grow but will not metastasize. Besides, the novel immunohistochemical pattern of LCA was described as CD31⁺/ERG⁺/FVIII Antigen⁺/CD68⁺/CD163⁺/lysozyme⁺/CD8⁻/WT1⁻.

Conclusion

LCA should be reconsidered as a benign primary splenic vascular neoplasm, which is more like an intra-splenic manifestation of abnormal body function. Image-guided biopsy with follow-up might be a beneficial choice for LCA patients. For LCA patients with abdominal discomfort, pathological uncertainty or continuous tumor enlargement, splenectomy remains the preferred treatment.

Incidental Splenic Findings on Cross-Sectional Imaging

Incidental splenic focal findings are commonly encountered in clinical practice and frequently represent a diagnostic dilemma due to nonspecific imaging features. Most are benign, particularly in patients without a history of malignancy and without symptoms of fever, weight loss, or left upper quadrant or epigastric pain. Incidental malignant splenic processes are exceedingly rare. This article reviews imaging characteristics of incidental focal splenic findings, and proposes a practical approach for management of such findings, which can prevent unnecessary workup and its related drawbacks in clinical practice.

Littoral cell angioma of the spleen: a study of 25 cases with confirmation of frequent association with visceral malignancies

AIMS

Littoral cell angioma (LCA) is a rare primary splenic tumour that is frequently associated with internal malignancies. Immunohistochemistry can demonstrate a distinct hybrid endothelial-histiocytic phenotype of littoral cells, and is a helpful adjunct for making the correct diagnosis. The aims of this study were to present a series of 25 LCAs, with an emphasis on the frequent association of the neoplasm with visceral malignancies, and to provide a detailed immunohistochemical analysis by employing new markers.

METHODS AND RESULTS

All 25 cases with available tissue blocks were immunohistochemically stained for endothelial and histiocytic markers. Clinical and follow-up data were retrieved from the respective institutions. The tumours were obtained from 16 males and nine females, whose age ranged from 32 to 86 years (mean 56.2 years). Clinical information was available for 24 of 25 patients, and follow-up for 11 of 25 patients (range 2-19 years; mean 11.6 years). Immunohistochemically, all cases were positive for LYVE-1, factor VIII, FLI-1, vascular endothelial growth factor receptor (VEGFR)-2, VEGFR-3, claudin-5, ERG, LMO2, CD31, CD163, lysozyme, and CD4, but negative for D2-40, CD8, and factor XIIIa. Fifteen of 25 cases were associated with various malignancies, including epithelial, mesenchymal and haematological tumours.

CONCLUSIONS

The cohort of 25 patients is the largest series of LCAs published to date. By using antibodies against recently introduced endothelial markers, we have expanded the immunoprofile of LCA. We have further highlighted the clinical significance of LCA, as more than half of the patients in this study also harboured a coexisting visceral malignancy. Therefore, we conclude that the finding of splenic LCA mandates a thorough clinical evaluation for a concomitant malignancy.

Littoral cell angioma in a patient with Crohn's disease

Littoral cell angioma is a rare vascular tumor of the spleen. The pathogenesis is unknown but the lesion is associated with several malignancies and immunological disorders. The diagnosis requires histopathological examination. The malignant potential of this lesion is unknown, which is why splenectomy is recommend for all cases. Symptomatic cases generally suffer from hypersplenism and pyrexia. A previously healthy 20-year-old female was diagnosed with colonic Crohn's disease; as part of the work-up a magnetic resonance enterography was performed which showed multiple signal changes of the spleen. The patient reported chronic abdominal pain in the left upper quadrant, malaise, and fever. The unknown splenic lesions prompted a laparoscopic splenectomy; pathology revealed a littoral cell angioma. The abdominal pain and malaise remitted but the fever persisted one year despite adequate treatment of the patient's Crohn's disease. Littoral cell angioma is associated with immune-dysregulation including Crohn's disease with several reported cases. Signs and symptoms of hypersplenism and splenic lesions on imaging should raise suspicion of littoral cell angioma in patients with Crohn's disease. Magnetic resonance enterography to assess disease severity in Crohn's disease may provide an opportunity to study the prevalence and natural history of this rare splenic tumor.

Littoral cell angioma of the spleen: sonographic-pathologic comparison

OBJECTIVES

The purpose of this study was to evaluate the sonographic and pathologic features of littoral cell angioma of the spleen in 7 patients.

METHODS

The sonographic appearance in 7 cases of littoral cell angioma confirmed by surgical pathologic examination was retrospectively reviewed. All underwent color Doppler imaging. Two underwent contrast-enhanced sonography. The sonographic appearance was compared with pathologic findings.

RESULTS

Splenic lesions were solitary in 5 cases and multiple in 2 cases. The masses ranged from 10 to 64 mm in maximum diameter. Five hypoechoic and 2 hyperechoic lesions on grayscale sonography corresponded to few and multiple blood-filled spaces on pathologic examination, respectively. Four hypovascular lesions, 1 hypervascular lesion, and the other 2 hypervascular lesions full of color flow signals on color Doppler imaging corresponded to few, several, and multiple arteries on pathologic examination. On contrast-enhanced sonography, 1 hypervascular lesion full of color flow signals showed homogeneous hyperenhancement for 8 minutes during the arterial and parenchymal phases. One hypovascular lesion showed inhomogeneous isoenhancement transiently during the arterial phase and became hypoechoic later.

CONCLUSIONS

Littoral cell angioma is a primary vascular splenic neoplasm with variable features on grayscale sonography and color Doppler imaging as well as contrast-enhanced sonography. The sonographic appearance of littoral cell angioma mainly depends on the type and number of tumor vessels.

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.