Retroperitoneal Cystic Masses: CT, Clinical, and Pathologic Findings and Literature Review

Abstract

Cystic lesions of the retroperitoneum can be classified as either neoplastic or nonneoplastic. Neoplastic lesions include cystic lymphangioma, mucinous cystadenoma, cystic teratoma, cystic mesothelioma, müllerian cyst, epidermoid cyst, tailgut cyst, bronchogenic cyst, cystic change in solid neoplasms, pseudomyxoma retroperitonei, and perianal mucinous carcinoma. Nonneoplastic lesions include pancreatic pseudocyst, nonpancreatic pseudocyst, lymphocele, urinoma, and hematoma. Because the clinical implications of and therapeutic strategies for retroperitoneal cystic masses vary depending on the cause, the ability to noninvasively differentiate between masses is important. Although there is substantial overlap of computed tomographic (CT) findings in various retroperitoneal cysts, some CT features, along with clinical characteristics, may suggest a specific diagnosis. CT may provide important information regarding lesion location, size, and shape; the presence and thickness of a wall; the presence of septa, calcifications, or fat; and involvement of adjacent structures. The most important clinical parameters include patient gender, age, symptoms, and clinical history. Familiarity with the CT and clinical features of various retroperitoneal cystic masses facilitates accurate diagnosis and treatment.

Retroperitoneal lymphangioma: A report of 2 cases and a review of the literature regarding the differential diagnoses of retroperitoneal cystic masses

“…A variety of neoplastic retroperitoneal cystic neoplasms (Table I), in particular pancreatic cystic neoplasms (Table II), and non-neoplastic cystic masses (Table III) are considered in the differential diagnosis when a retroperitoneal cystic mass is found (14,15).…”

Mucinous cystadenoma of the retroperitoneum, laparoscopy or an open approach? Two case reports and review of the literature

“…Cystic lesions of retroperitoneum are rare clinical entities, among which primary mucinous cystadenoma is even more rare [2]. These lesions can be classified as neoplastic and non-neoplastic (Table 1).…”

Extragonadal teratomas of the adult abdomen and pelvis: a pictorial review

“…The ultrasound and CT appearances are not specific enough to differentiate them from other cystic masses. 5 On MRI, they tend to follow the signal intensity of fluid being hypointense on T 1 weighted imaging ( Figure 5b) and hyperintense on T2WI (Figures 4, 5a and 6) but may show hypointense foci on T2WI, possibly secondary to keratin. 10 Positron emission tomography CT can help to distinguish malignant teratomas in the pre-treatment work-up.…”

“…5 They usually occur in the presacral space 5 ( Figure 4) but can also arise in the ischiorectal space ( Figure 5) and perineum ( Figure 6). When found in the retroperitoneum, they usually arise from the spleen.…”

“…Generally, cystic teratomas are more likely to be benign and solid teratomas more likely to be malignant. 5 However, benign mature teratomas can contain large solid components known as Rokitansky protruberances (RP). These are thickened areas within the cyst wall from which dermal appendages such as teeth, bone and hair may arise if present.…”