A patient is presented in whom a lymphocele developed after a retroperitoneal lymph node dissection for Stage I1 embryonal carcinoma of the testicle. The benign nature of this lymphocele has been confirmed not only by the diagnostic procedures outlined, but by its stability over a 42-month follow-up period with no further antitumor therapy. We conclude from reviewing the literature that while aggressive measures are necessary to confirm the diagnosis of a lymphocele, its management should be expectant. If significant obstruction of neighboring structures occurs, an attempt at percutaneous drainage (and possibly sclerosis) seems appropriate despite potential risks of interventional treatment such as hemorrhge and introduction of infection. Open procedures for marsupialization and drainage should be reserved for cases in which more conservative measures fail. Cancer 57:871-874, 1986. ETROPERlTONEAL LYMPH NODE DISSECTION has a R major role in the staging and treatment of nonsem-inomtous germ-cell tumors of the testicle. An unusual sequel to this operation is the development of a clinically apparent lymph~cele.'-~ Since the development of ret-roperitoneal masses postoperatively may represent tumor recurrence,5 awareness of the means to definitively diagnose lymphoceles is important to all physicians caring for patients with testicular cancer. We present an illustrative case and review the literature concerning the formation and natural history of lymphoceles, means for their prevention , and indications for, and methods of, therapy. Case Report At age 24, a previously healthy man presented with a left testicular mass. He underwent a left radical orchiectomy which revealed an embryonal cell carcinoma. Alpha-fetoprotein (AFP) and @-HCG were elevated 1 week postoperatively. A CT scan revealed enlarged abdominal lymph nodes and a chest x-ray was unremarkable. A transabdominal retroperitoneal node dissection (RND) was performed. At surgery, there were obviously enlarged retroperitoneal lymph nodes to the left of the aorta. Because of gross nodal involvement, the dissection was carried down to the psoas margin. In the closure, the posterior leaves of the perito-neum were reapproximated over the great vessels. The pathologic From the examination revealed metastatic embryonal cell carcinoma in 12 lymph nodes. No perioperative heparin was given. One month after the RND, AFP and P-HCG levels were normal. Two months post-RND, the 0-HCG was 8.9 (normal < 5) and an obvious abdominal mass was present on physical examination. CT scan of the abdomen revealed a 4.5 X 4.6 X I 1.0 cm cystic mass in the left retroperitoneum, which extended from the lower pole of the left kidney to the pelvic brim (Fig. 1). This homogeneous , fluid density, thin-walled structure was well demarcated and was situated immediately anterior to the left psoas muscle on which it left an impression. Under CT guidance a thin needle was passed into the center of this mass and clear yellow fluid was obtained. The fluid had no abnormal cells, a cholesterol of 39 mg...