Acrometastasis of Occult Renal Cell Carcinoma: A Case Report.

Renal cell carcinoma is a common malignancy with 30,000 new cases reported annually in the U.S. While bone is one of the most common sites of metastases of renal cell carcinoma, acrometastases are rare with an estimated incidence of 0.1 percent among patients with malignant disease. We present an 89-year-old white male who presented with a painful mass of the left thenar eminence. A preoperative medical evaluation revealed metastatic renal cell carcinoma with lytic infiltration of the diaphysis of the left thumb metacarpal with soft tissue involvement. The patient was treated with two intralesional currettage procedures and later radiation therapy. This approach allowed the patient to maintain functional use of the thumb for activities of daily living.

An Incidental Finding of Paratesticular Malignant Mesothelioma During Operation for Hydrocelectomy.

Paratesticular malignant mesothelioma is a rare and potentially aggressive malignancy, accounting for approxi- mately 0.3-1.4 percent of all malignant mesotheliomas. The tumor presents as a painless scrotal mass associated with recurrent hydrocele. We report an incidental case of paratesticular malignant mesothelioma in a 73-year- old man that was found during an operation to remove a progressively enlarging, symptomatic hydrocele. During the procedure the surgeon noted multiple, irregular, extratesticular masses, and subsequently submitted a sam- ple for frozen section analysis. Frozen section assessment revealed a papillary-appearing, malignant tumor and the surgeon proceeded with a radical orchiectomy. Examination of the orchiectomy specimen revealed multiple, yellow-white, papillary, exophytic excrescences that tracked along the hydrocele and coursed up the tunica vagi- nalis of the spermatic cord. Microscopically, the tumor was composed of papillary fronds and nests of malignant cells with enlarged, hyperchromatic, pleomorphic nuclei. Pankeratin and calretinin immunohistochemical stains strongly highlighted the tumor cells, supporting the diagnosis of malignant mesothelioma. Suspicion of malignant mesothelioma as a differential diagnosis in the setting of enlarging hydrocele is imperative, as the care of the patient is dramatically altered to address the aggressive nature of the disease and the unfavorable outcome.