Imaging of Uncommon Retroperitoneal Masses

Abstract

Retroperitoneal masses not arising from major solid organs are uncommon. Although there is no simple method of classifying retroperitoneal masses, a reasonable approach is to consider the masses as predominantly solid or cystic and to subdivide these into neoplastic and nonneoplastic masses. Because the treatment options vary, it is useful to be able to differentiate these masses by using imaging criteria. Although the differential diagnosis of retroperitoneal masses can be narrowed down to a certain extent on the basis of imaging characteristics, patterns of involvement, and demographics, there is still a considerable overlap of imaging findings for these masses, and histologic examination is often required for definitive diagnosis. Computed tomography (CT) and magnetic resonance (MR) imaging play an important role in characterization and in the assessment of the extent of the disease and involvement of adjacent and distant structures. Familiarity with the CT and MR imaging features of various retroperitoneal masses will facilitate accurate diagnosis and staging for aggressive lesions.

Lymphangioma of the small bowel mesentery in a 7-year-old girl: a report of a case investigated with ultrasonography, elastosonography and computed tomography

“…On CT images, fluid content is typically homogeneous and its attenuation ranges from that of water to that of fat, showing negative attenuation values when chyle is present. Calcifications may occur, but are uncommon [2,[4][5][6]. In our case, CT images did not show large cystic cavities, however were appreciated low-negative attenuation areas, due to fattychylous component, and some calcifications also.…”

“…Lymphangioma is a mass-forming lesion which usually presents in the first few years of life with 50-60 % manifesting by age 1 year and 90 % by age 2 years, while in our case the little patient was 7-year-old [4,6,7]. Although the incidence of abdominal LAs is unknown, they represents for 3-9.2 % of all pediatric LAs, and among these, LA of the small bowel mesentery, has been described in less than 1 % of all LAs [3,6,7].…”

“…Although the incidence of abdominal LAs is unknown, they represents for 3-9.2 % of all pediatric LAs, and among these, LA of the small bowel mesentery, has been described in less than 1 % of all LAs [3,6,7]. Histologically, LAs can be distinguished into three types: capillary or simple, cavernous, and cystic.…”

“…Lymphangioma (LA) is a benign proliferation of thinwalled lymphatic tissue believed to originate from the early failure of communication of lymphatic spaces with the normal main draining lymphatic vessels, thus being considered a congenital malformation rather than an acquired tumor [4,6,7]. It is usually found in the head and neck (50-75 %) and axillary (20 %) regions during the first few years of life, while other locations are more rare [4,7].…”

Malignant fibrous histiocytoma in a patient presenting with urinary system symptoms

“…Ultrasonographically, the tumor has a hypoechoic mass character and necrotic/hemorrhagic components are seen as hypoechoic or anechoic images with septated formations. 6,8 Typical CT findings include a large infiltrative mass with ill-defined borders and density similar to that of muscle tissue. Hypodense areas secondary to necrotic and hemorrhagic components and hyperdense calcific components cause non-homogeneity.…”