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

Abstract

BackgroundAs 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.MethodsThis 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.ConclusionThe 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 Malignant Lesions in Lymphoma and Solid Tumors, A Comparative Study of Imaging Techniques.

“…6,10,11,14,[24][25][26] In our study, no differences were seen between lymphoma and solid tumors according to the presence of other organ involvement. In other words, when we detected a splenic tumor, there were no differences between lymphoma and solid tumors regarding the presence of other organ involvement.…”

“…In this study, patients mostly had lung, colorectal and ovarian cancer. 10 In other studies, splenic metastases are mostly associated with choriocarcinoma, malignant melanoma and lung, breast, gastric, pancreas and ovarian cancer. In lymphoma, lesions are usually multiple and smaller than 1 cm, but large, solitary lesion and splenomegaly may be seen on CT. 1,6,7,[15][16][17][18][19] In lymphoma, solid lesions may also be seen in the spleen on US.…”

Imaging of the spleen: what the clinician needs to know

“…The absence of wall-thickening, intralesional solid components or contrast-enhancement is in favour of benign lesions. (14) …”

“…8). (14) MR imaging typically shows a very high signal on T2-WI and variable signal intensity on T1-WI, depending on the lesion content (either serous, haemorrhagic, proteinaceous or necrotic). …”

“…They show prolonged contrast enhancement due to their histological structure of multiple vascular channels on CT as MR imaging. (14) A littoral cell angioma is of marked low signal intensity on both T1-and T2-WI, due to the haemosiderin content. However, as haemosiderin is not always present, the absence of low signal foci does not exclude the diagnosis of littoral cell angioma.…”