Jejunal stromal tumor with skeinoid fibers or myenteric plexoma: a case report.

Small intestinal stromal tumors with 'skeinoid fibers' are uncommon stromal tumors with an associated controversial histogenesis. Although their microscopic appearance is suggestive of a smooth muscle nature, they lack specific smooth muscle features, as evident by electron microscopy and immunohistochemistry. They also appear to lack features of neurogenic origin because they fall to react with neural/neuroendocrine markers such as S-100 protein, neuron-specific enolase and chromogranin. It is interesting, nonetheless, to note that the ultrastructural examination of these tumors may show structures reminiscent of neural differentiation, such as cytoplasmic projections, containing occasional membrane-bound, dense-core, neurosecretory-type granules, which mimick the long cytoplasmic processes seen in tumors of neural origin. Moreover, the association of these tumors with Von Recklinghausen's neurofibromatosis, as well as the presence of 'skeinoid fibers' in proven neurogenic spindle cell neoplasms such as gastrointestinal autonomic nerve tumors and schwannomas, suggests that these tumors might also be neurogenic in origin and enhances the diagnostic value of 'skeinoid fibers' as a possible ultrastructural marker of neural differentiation. Thus, light microscopic evaluation is clearly insufficient to accurately diagnose these tumors and to determine their histogenesis, electron microscopic and immunohistochemical studies being necessary. In this article the histogenesis of small intestinal stromal tumors with 'skeinoid fibers', regarding a jejunal neoplasm in a 63-year-old patient, is reviewed. The light microscopic, immunohistochemical and ultrastructural features are described and compared with findings usually seen in all those stromal tumors which may raise a differential diagnosis, such as smooth muscle stromal tumors, gastrointestinal autonomic nerve tumors, schwannomas, paragangliomas and fibrosarcomas.

Pulmonary hemorrhage and antiglomerular basement membrane antibody-mediated glomerulonephritis after exposure to smoked cocaine (crack): a case report and review of the literature.

A case of Goodpasture's syndrome with a negative immunofluorescence examination of the lung biopsy in a 32-year-old man is described. The patient was a 40 cigarettes per day smoker, who had been smoking cocaine (crack) up to 3 weeks before hospital admission. He developed a diffuse alveolar hemorrhage with extremely acute respiratory distress, followed by renal failure with anuria. Transjugular renal biopsy, immunofluorescence and serum antiglomerular basement membrane antibody titer studies confirmed the diagnosis of Goodpasture's syndrome without linear immunoglobulin G deposits as determined by immunofluorescence examination of the alveolar basement membranes. The case illustrates the potentially complex interrelations between an autoimmune disease and exposure to substances with possible antigenic properties, besides the imperative necessity for an early, accurate diagnosis and treatment for the potential for threatening life. Moreover, the association of Goodpasture's syndrome with crack has not been previously reported.

[Sebaceous carcinoma of salivary gland. Report of two cases of infrequent location]. / Carcinoma sebáceo de glándula salivar. A propósito de dos casos de localización infrecuente.

Sebaceous carcinoma is an infrequent tumor of tardy increase, locally aggressive, potentially recurrent, with natural propensity for metastasize, both loco-regional or remote (lymphogenous or hematogenus metastases). Principal sitting are the annexed glands to ocular sense (Zeis glands and specially Meibomian's). Its origin in salivary glands is exceedingly uncommon, only those arising in the parotid have been reported. Our contribution are 2 cases which source were the sublingual gland and a minor palatine salivary gland, respectively. The perusal of the literature has been negative: no one previous case of sebaceous carcinoma could be discovered in the literature.