POSITRON EMISSION TOMOGRAPHY DETECTION OF METASTATIC PENILE SQUAMOUS CELL CARCINOMA

Abstract

A 58-year-old white man presented elsewhere with small white lesions on the glans of the penis in 1992. History included circumcision at age 16 years and multiple sequential rigid dilations for urethral stricture. Balanitis xerotica obliterans was diagnosed and treatment was local. The area became sore 5 years later and a biopsy revealed squamous cell carcinoma. The patient underwent Mohs’ procedure and was disease-free for the next 15 months when a recurrent lesion, just ventral to the meatus, was positive for squamous cell carcinoma. No palpable inguinal adenopathy was identified and a chest x-ray was negative for metastatic disease. The patient was referred to us and we recommended partial penectomy. In 1998 he underwent a wide wedge resection of the glans penis, meatus and distal urethra with plastic reconstruction of the distal penile shaft to accommodate a new meatus. Pathological examination confirmed invasive, well differentiated, keratinizing squamous cell carcinoma. All surgical margins were free of tumor. A firm mass in the left groin was palpated 2 years later. Computerized tomography (CT) of the pelvis identified a 3.5 3 2.5 cm. heterogeneous left inguinal mass consistent with nodal spread of penile carcinoma. No intravenous contrast material was given due to iodine allergy. Left superficial and deep inguinal lymph node dissection revealed metastatic keratinizing squamous cell carcinoma in 2 of 12 superficial lymph nodes. The largest positive node was 3 cm. and showed extracapsular invasion. All resected deep nodes were negative. The postoperative course was complicated by an increased drainage from the Jackson-Pratt drain, increased wound swelling and wound separation requiring daily packing and home nursing care. The patient noticed a small single nodule on the left anterior upper thigh 2 months after discharge from the hospital. Abdominal and pelvic CT without intravenous contrast material revealed multiple surgical clips and ill defined soft tissue at the left groin surgical site (fig. 1, A). Inferiorly in the left groin, there was a 4.5 3 4.5 cm. fluid attenuation lesion (fig. 1, B). It was difficult to discern between recurrent disease versus postoperative changes. CT of the chest showed multiple bilateral pulmonary nodules suspicious for metastatic disease. It is noteworthy that no hilar adenopathy was visualized. Whole body positron emission tomography after the intravenous injection of 11.39 mCi. F-18 fluorodeoxyglucose demonstrated multiple foci of increased fluorodeoxyglucose activity in the left groin, left upper thigh, left iliac chain and right groin (fig. 2). One of the abnormal areas of fluorodeoxyglucose activity in the left groin had central decreased uptake, which corresponded to the fluid collection on CT (fig. 2). In addition, there were punctuate foci of abnormal increased fluorodeoxyglucose uptake in the chest. A single focus was seen in the left upper lobe, which corresponded to a nodule on CT. Foci of increased activity were noted in both hila suspicious for metastatic disease, although no lymphadenopathy was visualized on CT.