Myelolipoma of the Pelvis: A Case Report and Review of Literature.

Myelolipomas are uncommon, benign tumors which typically occur in the adrenal glands and consist of mature adipose tissue and benign hematopoietic components. Myelolipomas can occur outside of the adrenal glands, but the presacral region, retroperitoneum, pelvis, and mediastinum are unusual locations for these tumors. It is important to recognize this entity in these locations since they can attain massive sizes leading to pressure symptoms and need to be differentiated from the malignant tumors like liposarcomas. We present a myelolipoma case in the presacral region. Our case illustrates the clinical approach of these tumors in such unusual locations.

Malignant epithelioid peripheral nerve sheath tumor arising in a benign schwannoma.

The case of a patient with malignant degeneration of a solitary abdominal schwannoma and endobronchial metastasis is presented. The patient presented clinically with dyspnea referable to her lung mass, anorexia, and night sweats. The lung mass, initially diagnosed as a large-cell undifferentiated carcinoma, was later found to be histologically identical to the malignant portion of the abdominal tumor. The light microscopic, electron microscopic, and immunoperoxidase staining characteristics of the tumor are reported, and previous reports in the literature are reviewed.

Comparative analysis of mechanical and bioprosthetic valves after aortic valve replacement.

Comparative long-term performance characteristics of Björk-Shiley mechanical and bioprosthetic valves were analyzed for patients undergoing aortic valve replacement between 1976 and 1981. A total of 419 patients received either a standard Björk-Shiley (n = 266) or bioprosthetic (porcine, n = 126, or pericardial, n = 27) aortic valve. Cumulative patient follow-up was 1,705 patient-years; the average patient follow-up was 4.1 +/- 2.7 years. Survival data were obtained for all but 11 patients (97% complete follow-up) up to 9 years after operation. Survival at 5 years was 81% +/- 4% (+/- standard error) for Björk-Shiley and for bioprosthetic valve recipients. Valve failure in the Björk-Shiley group was predominantly due to valve-related mortality and did not result from structural failure. Patients with bioprosthetic valves experienced valve failure as a result of prosthetic valve endocarditis and intrinsic valve degeneration. Although patients with bioprostheses experienced a lower incidence of valve-related morbidity than Björk-Shiley valve recipients (p less than 0.03), no difference could be demonstrated in the incidence of valve-related mortality or valve failure at 5 years between bioprosthetic and Björk-Shiley valves. Mortality rate from valve failure was higher for Björk-Shiley (86%, 12/14) than bioprosthetic valves (36%, 5/14) (p less than 0.01).

Ten-year analysis of the Björk-Shiley standard aortic valve.

Long-term performance characteristics of the Björk-Shiley standard aortic valve were determined by analyzing the follow-up of 514 patients undergoing operation between 1971 and 1981. Cumulative follow-up was 2,601 patient-years (average, 5.3 +/- 3.8 years); 53% (238/452) of hospital survivors have been followed more than 5 years. Valve-related complications expressed as both actuarial event-free percents (+/- standard error at 10 years) and first-event linearized determinations (percent per patient-year) occurred at the following rates: thromboembolism, 82 +/- 3 and 2.3 +/- 0.3, respectively; anticoagulant-related hemorrhage, 60 +/- 4 and 5.6 +/- 0.5; prosthetic valve endocarditis, 94 +/- 2 and 0.8 +/- 0.2; valve thrombosis, 97 +/- 1 and 0.4 +/- 0.1; reoperation, 94 +/- 2 and 0.6 +/- 0.2; valve failure, 82 +/- 4 and 1.6 +/- 0.2; and composite valve-related morbidity and mortality, 46 +/- 4 and 8.8 +/- 0.2. Overall survival was 72 +/- 2% at 5 years and 55 +/- 3% at 10 years; valve-related complications accounted for 22% of the late deaths. Although no instance of structural valve failure could be identified, 25% of valve-related complications resulted from valve failure, of which 67% were fatal. By 10 years, 54% of patients had experienced at least one form of major valve-related complication, 16% of which proved fatal. The Björk-Shiley standard aortic valve has late valve-related complications similar to other existing mechanical prostheses that have been subjected to long-term analysis.