Splenic cysts

Aetiological classification

• Non-parasitic
  • Type 1 (primary - 10%)
    • True cysts - epithelial lining
    • Often positive for CA19-9 and CEA
    • Congenital
    • Epithelioid - benign
    • Mesenchymal (rare)
    • Dermoid (rare)
  • Type 2 (secondary - 90%)
    • False cysts - no epithelial lining
    • Radiologically - smooth, thick-walled, unilocular, sometimes with focal calcifications
    • Usually post-traumatic - subcapsular haematoma that failed to reabsorb
    • Could also be secondary to prolonged splenic abscess or infarct
    • Asymptomatic <4cm pseudocysts do not require treatment and may involute with time
    • Consider surgical treatment as below
    • Aspiration generally leads to recurrence
• Parasitic
  • Usually caused by Echinoccous granulosus (hydatid cysts - see separate topic under Liver)
  • Splenectomy is usually treatment of choice

Presentation

• Splenomegaly - abdominal fullness, early satiety, pleuritic chest pain, shortness of breath, renal symptoms from compression of the left kidney, and left shoulder or back pain
• Can rarely present with acute rupture or haemorrhage or infection

Differential diagnosis

• Splenic tumours - lymphangiomas and cavernous haemangiomas can have a similar appearance

Clinical significance

• Primarily mass effect and potential to rupture and bleed

Management

• Splenectomy for symptomatic or large cysts
• Consider partial splenectomy - 25% of the spleen is enough to provide protection

Peliosis of the spleen

• Multiple cyst-like blood-filled cavities within the splenic parenchyma
• Thought to originate from sinusoidal dilation
• Usually an incidental finding
• Potential for splenic rupture