[A case of primary malignant melanoma of the esophagus].

A case of primary and malignant melanoma of the esophagus was reported. A 64-year-old male complaining of discomfort of anterior chest pain was admitted to our hospital for operation. Findings of upper G-1 X-ray and endoscopic examination revealed suspiciously malignant melanoma. Subtotal thoracic esophagectomy with R III dissection was performed. Operative findings included A0 N2 Pl0 M0 Stage III. Macroscopically it showed black-grayish colored polypoid tumors, 7 cm in size. The typical finding of junctional activity adjacent to the tumor mass and melanocytes were microscopically found. The patient received postoperative systemic chemotherapy, but was died of multiple liver and bone metastases 125 days after surgery. Malignant melanoma of the esophagus has extremely poor prognosis and none of effective therapies has been reported.

Primary malignant fibrous histiocytoma of the descending colon.

We herein present the case of a 50-year-old woman with malignant fibrous histiocytoma arising from the descending colon and localizing in the colonic wall. Malignant fibrous histiocytoma of the large bowel is a very rare tumor. A total of 18 cases, including our case, have been reported in the world medical literature so far and we also reviewed these cases. In our case, combined adjuvant chemotherapy was administered after a complete resection had been performed. No clinical signs of local recurrence or distant metastasis were found at 7 years after the operation.

[A case of malignant neuroepithelioma in the retroperitoneum].

Reported is a case of a malignant neuroepithelioma in the retroperitoneum. The patient was a 37-year-old male suffering from lumbago and edema of the lower extremities. After ultrasonography and a CT scan, a diagnosis of a retroperitoneal tumor was made and a surgical resection of the tumor was performed in October, 1985. The subsequent pathological diagnosis was malignant neuroepithelioma which showed epithelioid cell clusters that stained positively to NSE. Eleven months later, metastatic tumors were seen present in the lungs and the liver though they regressed markedly after adjuvant chemotherapy with ADM, CPM, and VCR. Forty-one months after his first operation, the patient continues to work. In this case, adjuvant chemotherapy has proved effective.

[Replacement of the anterior cruciate ligament (ACL) using a Dacron artificial ligament in the rabbit--biomechanical and histological studies].

The value of Dacron as an artificial ligament is currently being investigated in various areas. In the present study, histological findings and changes in the tensile strength of Dacron artificial ligament with time were investigated when it was used as a replacement of the anterior cruciate ligament in the rabbit in various ways. The study was intended to evaluate its mechanical strength when used as the cruciate ligament of knees and determine whether it can induce functional orientation of tissue and bone-ligament anchoring or not. Although the reactions of the Dacron ligament introduced into the joints varied according to individuals, synovial tissue was known to start surrounding the Dacron ligament, and then the fibrous tissues covered the ligament and proliferated into it, gradually acquiring a functional orientation. Also in bone tunnels, fibrous-bone formation was found to proceed gradually. Bone graft proved to be useful for the earlier establishment of the anchoring of the bone and ligament. Though the addition of the method to cover the ligament with synovialis enhanced tissue induction within it, collagen fibers still demonstrated a random orientation. However, the method of patella-tendon transfer in addition to the artificial ligament was recognized to be effective in inducing the functional orientation of tissue. The strength of the trans-grafted artificial ligament did not have to be great as long as it was reconstructed by the augmentation method.