A Large Splenic Epidermoid Cyst Initially Misdiagnosed as a Hydatid Cyst

Abstract

BACKGROUND Splenic cysts are classified as either parasitic or non-parasitic cysts, with both types sharing similarities in their clinical presentation and imaging findings. Most splenic cysts are of parasitic origin, while non-parasitic splenic cysts are less common. Splenic epidermoid cysts (SECs) are a rare subtype of non-parasitic cysts and compromise only around 10% of them. CASE REPORT In this paper we present a case of 22-year-old man with no significant past clinical history, who presented with non-specific, vague symptoms, including persistent left upper-quadrant pain and discomfort for the last 2 years. A physical examination and extensive laboratory tests were inconclusive. Subsequently, the patient underwent multiple imaging studies including ultrasonography and computed tomography (CT) scan of the abdomen. His ultrasonographic findings were consistent with the diagnosis of hydatid cyst, which was further emphasized by its frequent occurrence in clinical practice, as our country is considered an endemic region. In light of this, he underwent laparoscopic splenectomy following percutaneous cyst drainage. The consequent histopathological examination revealed the diagnosis of splenic epidermoid cysts. CONCLUSIONS When encountering splenic cysts in regions where parasitic infections are endemic, special attention is needed, as physical examination, laboratory tests, and imaging studies alone are insufficient to differentiate among the types of cysts. Histopathological examination remains the diagnostic tool of choice, particularly when imaging findings are inconclusive. Splenectomy, with either a laparoscopic or open approach, is the treatment of choice for splenic cysts to prevent recurrence as well as other potential catastrophic complications.

Figure 1.

Multiple, round, lobulated, fluid-density (20–40 HU) cystic lesions, most of them showing wall calcifications seen at the spleen, and multiple, small, round cystic lesions seen at the bilateral kidneys.

Figure 2.

Well-encapsulated, round, lobulated, fluid-density (20–40 HU) cystic lesion in the spleen, measuring 12.7×10.5 cm.

Figure 3.

Multiple small, round, lobulated, cystic lesions seen at bilateral kidneys. In addition, there were 2 circumscribed cystic lesions with wall calcifications seen at the spleen.

Figure 4.

(A) The outer capsule of the spleen shown here is inked green (empty white arrow) and the cut sections reveal multiple cysts of variable sizes present within the splenic parenchyma, with glistening, white, shiny lining (red arrows) and calcified hard areas (yellow areas). Superior view. (B) The capsule of the spleen is shown again (empty white arrow) and the largest cyst within the spleen is opened, revealing a denuded, coarse, fibrotic surface (yellow arrows). Superior view.

Figure 5.

(A) The lining of some of the cysts is composed of keratinizing squamous epithelium resembling the epidermis of the skin with the red arrow pointing to the keratin layer, the black arrow pointing to the multilayered squamous epithelium and the yellow arrow pointing at the collagen bundles of the underlying fibrous tissue. Original magnification, 400× (Hematoxylin and eosin stain). (B) Lower magnification of the cyst wall shows the stratified squamous lining (black arrow) and the underlying fibrous connective tissue (yellow arrow). Original magnification, 100× (hematoxylin and eosin stain).