IS Case 38: Splenic Epithelial Cyst
Imaging Sciences URMC 2008
Publication Date: 2009-05-19
Patient is a 13-year-old female with left abdominal pain with palpable mass.
US of the left upper quadrant demonstrates a 20 cm x 12 cm debris-containing cystic mass. No solid component or flow within the lesion was seen. Sonographic images demonstrated splaying of adjacent splenic parenchyma (the so-called "claw sign") suggesting that the spleen is the organ of origin. Correlative CT confirmed this finding.
Splenic Epithelial Cyst
Splenic cysts are uncommon, with an incidence of 7.6 per 100,000. True (epithelial-lined) splenic cysts are congenital, reflecting defective mesothelial migration. They account for 20% of all splenic cysts. These are typically smooth walled and may become large, often presenting in children due to mass effect, as in our case. Secondary hemorrhage, rupture or infection can also lead to presentation. These lesions are not thought to have malignant potential, but are excised if symptomatic or large (>6 cm). Acquired cysts, conversely, may be seen in any age group and reflect the endstage of an infarct or resorbed subcapsular or intraparenchymal hematoma. These cysts lack an epithelium, and thus are pseudocyts. Wall calcifications and irregularity are a common feature. These are the most common splenic cysts, accounting for 80% of all splenic cysts.
The differential diagnosis for a splenic cyst includes intrasplenic pancreatic pseudocyst, abscess (pyogenic, fungal, mycobacterial, or parasitic), hemangioma, and lymphangioma. Malignant etiologies including lymphoma and metastases (especially melanoma, pancreatic, and ovarian primaries) can also have a cystic appearance. Appropriate history, serologic testing and imaging characteristics aid in diagnosis.
- Vos, PM et al. The Spleen. In: Diagnostic Ultrasound, Rumack CM, Wilson SR, Johnson J-A, Charboneau JW (eds), 3rd. Ed., Elsevier Health Sciences, 2005, pp 147-150.
- Urrutia M, Mergo PJ, Ros LH, Torres GM, Ros PR. Cystic masses of the spleen: radiologic-pathologic correlation. Radiographics. 1996 Jan;16(1):107-29. [PMID: 10946694]
- Dachman AH, Ros PR, Murari PJ, Olmsted WW, Lichtenstein JE. Nonparasitic splenic cysts: a report of 52 cases with radiologic-pathologic correlation. AJR Am J Roentgenol. 1986 Sep;147(3):537-42. [PMID: 3526842]