Nonparasitic splenic cysts: pathogenesis, classification, and treatment

Nonparasitic splenic cysts (NPSCs) are uncommon lesions of the spleen, many being reported in anecdotal fashion. Early classifications of this disorder have been based on the presence or absence of an epithelial lining, indicating either a congenital or traumatic etiology. This criterion has led to confusion and mistaken reporting because the lining alone is not a reliable criterion.

Over a 28-year period, the author has observed and studied 23 patients with NPSC. Special attention has been given to the role of trauma in the history, the nature (or absence) of a cyst lining, the gross pathology, and the preferred method of treatment.

NPSC present as lesions with a very characteristic gross appearance and lining. The trabeculated interior can be lined with epidermoid, transitional, or mesothelial epithelium. Desquamation of the lining can lead to a spurious diagnosis, but careful search usually discloses the lining remnant. Although most NPSC in this series were treated by open partial splenectomy, the more recent approach by laparoscopic techniques offers great promise.

A new classification of NPSC is offered, based on characteristic gross findings. NPSC are of congenital origin, with a lining derived from mesothelium. Trauma does not play a primary role in pathogenesis. Cysts that are symptomatic or over 5 cm in diameter should be removed by partial splenectomy or near-total cystectomy "decapsulation," either by the open or laparoscopic approach.