Intrathoracic splenosis: A case report and an update of invasive and noninvasive diagnostic techniques

Abstract

Intrathoracic splenosis is a rare condition resulting from autotransplantation of splenic tissue into the left side of the chest, usually after diaphragmatic and splenic rupture after blunt or penetrating abdominal trauma. Patients are often free of symptoms, and nodules are usually discovered at computed tomographic scan. Owing to the rarity of the condition (30 cases in the literature so far), most patients undergo thoracotomy before final diagnosis. We present a case of thoracic splenosis that recently came to our attention. Clinical Summary A 67-year-old man had a left upper lobe mass identified during workup for prostatectomy for benign prostate hypertrophy. Medical history was unremarkable except for an injury that had occurred 43 years earlier with rib fractures, pneumothorax, and spleen rupture; no diaphragmatic rupture was evidenced. A chest tube was inserted and a splenectomy was undertaken at that time. Preoperative workup for the lung lesion included a chest and upper abdominal computed tomographic scan (Figure 1) and fineneedle aspiration of the lesion, revealing a mixture of inflammatory cells comprising mostly lymphocytes, plasma cells, and some pigment-laden macrophages in a background of hemorrhage and endothelial cells. The lymphocytes showed mixed immunoreactivity for CD3 and CD20 whereas tests for pankeratin were negative. With the suspicion of a neoplastic lesion, the patient underwent a left muscle-sparing thoracotomy. The parietal pleura displayed multiple small (0.5‐1 cm) nodules particularly evident on the diaphragmatic surface. An identical nodule (3 2 cm) was located along the aorta, from which it could be easily dissected and sent for frozen section examination: grossly, the surgical specimen was soft and displayed, at the cut surface, a brown color with diffuse small white dots (Figure 2, g). Microscopically, it was consistent with a benign spleen, with lymphocytic aggregates and other leukocytes distributed in a highly vascular background of sinusoidal structures (Figure 2, i). No further resection was therefore carried out. The patient had an uneventful postoperative course and was discharged from the hospital on postoperative day 6.