Tantalum balloon-expandable stent: in vivo swine studies.

PURPOSE: The authors describe the experimental use of a balloon-expandable tantalum vascular stent in normal and atherosclerotic microswine. MATERIALS AND METHODS: Thirty-one stents (15 iliac, 13 aorta, two femoral, one renal) were placed in 11 animals. Stents were placed in both normal and stenotic atherosclerotic arteries. The animals were killed and the stents explanted 2-32 weeks after placement. Arteriography was performed just prior to death in all cases. RESULTS: All stents were patent arteriographically and on gross inspection. Histopathologic study showed a thin, smooth, endothelial-lined neointima over the segments with stents. This covering had a mean thickness of 2.9 x 10(-5) mm and appeared maximally developed 2-5 weeks after stent placement. The stent design incorporates the following engineering and clinical considerations: minimal profile and surface area and maximal expansion ratio, hoop strength, flexibility, fluoroscopic visibility, biocompatibility, and ease of placement. When compressed and mounted on the balloon catheter, the stent is flexible. This allows it to be easily maneuvered through tortuous or diseased vessels. On expansion, the stent becomes a semirigid tubular structure composed of multiple rhomboid cells. Stents with an expanded diameter of less than 11 mm can be introduced through a 7-F vascular sheath. CONCLUSION: Initial results suggest that this stent successfully incorporates a number of theoretically desirable features for a vascular prosthesis, and it may offer some advantages over previously described devices.

Osteoblastoma of the nasal cavity.

The clinicopathological features of a rare case of osteoblastoma of the nasal cavity arising from the nasal turbinate are reported and compared with four reported cases of osteoblastoma with nasal cavity involvement. Two of the five tumours involved the nasal cavity and paranasal sinuses. The remaining three tumours were confined in the nasal cavity; one arose from nasal bone and two from nasal turbinate periosteum. Four tumours were successfully treated with local excision. One tumour recurred locally after excision; the recurrence was apparently controlled by further local excision.

Megakaryocytes in fine-needle aspiration biopsy of breast.

An unusual case in which megakaryocytes were found in fine needle aspirate of a breast lesion is reported. The megakaryocytes in the smears were initially mistaken to be malignant cells. However, the cell block sections available later showed normal bone marrow particles, indicating that an inadvertent puncture of a rib was the reason for the presence of megakaryocytes in the smears.

Annulate lamellae in human malignant tumors: report of three cases.

During the course of applying electron microscopy to diagnostic surgical pathological specimens, three malignant tumors (malignant melanoma, fibrous mesothelioma, lymphoblastic lymphoma) were found to contain annulate lamellae, distinctive intracytoplasmic organelles composed of membrane stacks interrupted by constrictions or pores. In one case both annuli and lamellae were present, a combination rarely described in human tissue and in animal models. In this material, the annuli of the annulate lamellae were structurally similar to nuclear pores. It is postulated that the abundant fibrils are probably related to the unusual configuration of the annulate lamellae. A morphologic relationship of the annulate lamellae to both the endoplasmic reticulum (cases 1 and 2) and the nuclear membrane (case 3) supports the theory that annulate lamellae may be related to both of these structures.

Massive hemorrhage from perforated thyroid complicating tracheostomy. Report of two cases.

Two cases of unusual hemorrhagic complication of tracheostomy involved perforation of the thyroid gland as the cause of hemorrhagic episodes. In one case, massive hemorrhage complicated the postoperative course of a 62-year-old man with dissecting aortic aneurysm. In the other, fatal hemorrhage occurred after tracheostomy through the thyroid gland in a 6-month-old boy. A major branch of the thyroid artery was ruptured adjacent to the tracheostomy wound. This is the sixth reported case of fatal hemorrhage from perforation of thyroid artery after tracheostomy, to our knowledge.

Pleomorphic carcinoma of the pancreas: an analysis of 15 cases.

Pleomorphic carcinoma of the pancreas is a well defined histopathological entity characterized by non-cohesive, sarcoma-like growth pattern, and bizarre mono- and multinucleated tumor giant cells with abundant eosinophilic cytoplasm. Fifteen cases are identified in autopsy files of the Department of Pathology, Washington University School of Medicine, which represent 7.1% of all the non-endocrine pancreatic malignancies found at autopsy. Pleomorphic carcinoma is comparable to pancreatic adenocarcinoma in clinical features such as age, sex, and presenting symptoms except that it is more likely to occur in the body and tail of the pancreas, metastases invariably develop, hematogenous spread is more common, and the median survival is worse. Pleomorphic carcinoma could be distinguished from the pancreatic tumors that resemble giant cell tumor of the bone. Differential diagnostic features between it and amelanotic melanoma, hepatocellular carcinoma, choriocarcinoma, pleomorphic liposarcoma, pleomorphic rhabdomyosarcoma, fibroxanthosarcoma, poorly differentiated epidermoid carcinoma, and giant cell carcinomas of the lung and thyroid are discussed.

Testicular relapse in childhood acute lymphocytic leukemia during bone marrow remission.

Seven children with acute lymphocytic leukemia developed testicular swelling during bone marrow remission. Needle biopsies and one orchiectomy specimen revealed leukemic infiltration. Another patient encountered concurrent medullary and testicular relapses. The leukemic nature of the testicular infiltration can be readily confirmed on needle biopsies. Orchiectomy should be discouraged. The leukemic infiltration mainly took place in the interstitial spaces. The seminiferous tubules were atrophic and lined by Sertoli cells. Occasional spermatogenic cells could be found in some cases. The leukemic cells were also observed to invade and accumulate beneath the Sertoli cell layer. Destruction of the tubules by the infiltrate was seen in advanced cases. Postradiation biopsies were characterized by fibrosis. The sigeveloped subsequent marrow relapse despite the effective control of the testicular relapse by irradiation. Another important observation is the high incidence of testicular relapse (16.2% so far).

Nodular malignant lymphoma and amyloidosis. A case report.

A case of long-standing, nodular malignant lymphoma of lymphocytic type associated with nephrotic syndrome and systemic amyloidosis is presented. Review of literature revealed only six previously reported cases of systemic amyloidosis complicating non-Hodgkin's lymphomas. Recent studies have revealed that all of the nodular lymphomas are B-lymphocyte malignancies; that nodular lymphomas have high incidence (46-64%) of abnormality of intracellular immunoglobulin synthesis; that abnormality of serum immunoglobulin in such patients in uncommon (0-8%); and that at least one type of amyloid fibrils is made up of immunoglobulin light chains. These findings would suggest that there is an etiologic relationship between nodular lymphoma and systemic amyloidosis.

Multiple sebaceous adenomas and internal malignant disease: a case report with chromosomal analysis.

A case of multiple sebaceous adenomas associated with internal malignant disease is further documented. Thirteen similar cases reported in the literature are also reviewed. We support the thesis that this association represents a unique syndrome. It can be seen in both sexes and usually is manifested during the fifth and sixth decades. A family history of malignant disease was revealed among seven of the nine cases mentioned. Of the other skin lesions, keratoacanthoma is also frequently seen. The internal malignant tumors most commonly afflict the gastrointestinal tract, especially the large intestine. With proper treatment the internal tumors appear to be of a low degree of malignancy. However, these patients have a propensity to develop muliple visceral tumors and require periodic follow-up. Some patients develop skin tumors prior to the discovery of internal malignant disease, an event that offers some prognostic value. Chromosomal study of the cultured blood lymphocytes by the Giemsa banding technique failed to reveal any abnormality.