Atraumatic rupture of the spleen in periarteritis nodosa

A case of atraumatic rupture of the spleen is described. The underlying disease was found to be periarteritis nodosa. Involvement of the spleen is common in this disease, but to our knowledge atraumatic rupture of this organ in a patient with histologic verified periarteritis nodosa has not previously been reported. In the present case the splenic rupture was the incident which led to the diagnosis. A possible mechanism of the rupture is proposed.