No abstract

This experimental study was designed to investigate the risk of tumor dissemination by hepatic cryosurgery and to determine the final subzero temperature required for effective hepatic tumor cryoablation. Although cryosurgery is now one of the established modalities for the treatment of some liver tumors and has been used for two decades, controversy remains regarding the final subzero temperature needed to destroy tumor masses. One experimental report has indicated that hepatic cryosurgery may enhance tumor dissemination. For this study, rat hepatic tumors were produced by direct injection of rat colonic carcinoma cells (DHD/K12/TRb). The control untreated animals (n = 12) were sacrificed after induction of liver tumors at 4 and 6 weeks. The animals in the treatment group (n = 16) underwent cryosurgery 2 weeks after tumor induction and were allowed to recover before sacrifice 2 and 4 weeks later. Pulmonary metastases were identified in 9 of 12 (75%) control animals at postmortem examination (2 and 6 weeks after tumor inoculation) and in 6 of 16 (38%) rats in the treatment group at sacrifice 2 and 4 weeks after cryosurgery (p = 0.11, Fisher's test for unpaired analysis). Peritoneal deposits were observed in 5 of 12 (42%) control animals at postmortem examination and in 8 of 16 (50%) of the treated animals at the time of cryosurgery (p = 0.95, Fisher's test for unpaired analysis). Two other study animals developed deposits after cryosurgery. The prevalence of peritoneal deposits in the study group was not altered by cryosurgery (p = 0.5, McNemar's test for paired analysis). The importance of the final subzero temperature at the edge of the iceball during tumor ablation by cryosurgery was confirmed by the histologic findings. Complete ablation with no residual viable tumor was obtained only when the subzero temperature had reached -38 degrees C or below. The results of this study do not support the suggestion that hepatic cryosurgery enhances tumor dissemination. The findings also confirm that a subzero temperature at the edge of the iceball of -38 degrees C or lower is necessary to ensure complete ablation of tumor.

We conducted a study to evaluate the success of facial nerve preservation in 27 adults with a parotid tumor who underwent total parotidectomy. Of this group, 11 patients had a malignant tumor, 10 had a recurrent benign tumor, and 6 had a primary benign tumor. Preoperatively, 7 patients had facial nerve paresis. Postoperatively, facial nerve preservation was achieved in all but 1 case; in the exception, the nerve was sacrificed and grafting was necessary. In conclusion, facial nerve preservation can be achieved in almost all cases of total parotidectomy.

Renal cell carcinoma (RCC) may metastasize anywhere in the body and sometimes the primary tumor is missing and necessitates extensive investigations to detect. In this report, we describe a case of RCC metastasizing to the thigh in a 70 year old male with a highly pleomorphic morphology suggesting a high grade sarcoma that showed unequivocal positivity for desmin directing the diagnosis for pleomorphic rhabdomyosarcoma. After completion of 33 cycles of radiotherapy, the patient developed large intraabdominal mass that showed conventional areas of RCC with immunoreactivity for CD10, CK, EMA, carbonic anhydrase IX and vimentin. The tumor cells in other areas resembled that of thigh mass which raised suspicions whether the two masses represented the same tumor or not. Surprisingly, the tumor cells of thigh mass showed diffuse positivity for CD10 and focal expression for CK, EMA and carbonic anhydrase IX. Extensive investigations failed to detect any primary renal lesions. The present case demonstrated that RCC can metastasize to virtually any body site and can have significant morphologic overlap with other non-renal neoplasms. Absence of primary origin of RCC according to radiological and operative data should not hinder the diagnosis of metastatic RCC. RCC with sarcomatoid and rhabdoid features carries aggressive behavior manifested by great metastatic potential and short survival time.