Hepatic angiomyolipoma with striated granules and positivity with melanoma--specific antibody (HMB-45): a report of two cases.

Angiomyolipoma occurs rarely in the liver, with only 25 previous cases being reported in the English literature. The article describes two additional cases, one of which was multicentric, with results of ultrastructural and immunocytochemical studies. Many of the tumor cells contained numerous electron-dense granules, some with transverse striations like those found in melanosomes. Both tumors stained positively for S-100 protein and melanoma-specific antibody HMB-45. One case also expressed vimentin and neuron-specific enolase. Both were negative for cytokeratin, carcinoembryonic antigen, alpha-fetoprotein, desmin, muscle-specific actin, factor VIII antigen, and chromogranin. Comparison of our ultrastructural findings with those of classic renal angiomyolipoma raises the possibility that the melanosomelike structures may represent renin granules rather than melanosomes, although the latter are not excluded. Expression of HMB-45 in angiomyolipoma has important biologic and diagnostic implications, whether or not it reflects melanocytic differentiation.     

Rhabdoid tumor of kidney. A report of 111 cases from the National Wilms' Tumor Study Pathology Center

We review 111 cases of rhabdoid tumor of kidney (RTK), including 79 entered on the National Wilms' Tumor Study (NWTS). Median age at diagnosis was 11 months, with a range from 0 to 106 months. The male:female ratio was 1.5:1. Gross features included a characteristic involvement of perihilar renal parenchyma. A wide histological spectrum was encountered, including nine major morphological patterns (classical, epithelioid, sclerosing, lymphomatoid, histiocytoid, etc.). These appearances invite confusion with other renal neoplasms. Ultrastructural studies were performed in 20 cases; immunocytochemical studies were performed in 11. Vimentin was demonstrated in all tumors; epithelial membrane antigen was seen in 7. Nonspecific decoration of cytoplasmic inclusions by a variety of immunostains was found in several cases. Several findings suggested that RTK might arise from primitive cells involved in formation of the renal medulla. There was no evidence of a histogenetic relationship to Wilms' tumor, although RTK may overlap with mesoblastic nephroma and clear cell sarcoma. Of the 70 NWTS patients with adequate follow-up, 56 (80%) have died. Every patient presenting with distant metastases died, whereas 10 of 20 with negative nodes survived. Survival rates were higher for girls (56.3% versus 11.1%). None of the histological variables had independent prognostic significance.     

Pain after barium enema: effect of CO2 and air on double-contrast study

One hundred fifty-one consecutive patients scheduled for double-contrast barium enema studies were assigned randomly to insufflation with either air or carbon dioxide (CO2) in a double-blind, prospective trial. Within 24 hours after the enema study, the patients were contacted by telephone by an interviewer, who completed a standard questionnaire. Radiographs from the enema studies were assessed for quality by two radiologists. Pain experienced after the procedure was graded from 0 (none) to 4 (severe). Clinically relevant (grades 2-4) pain was experienced by 30% of patients after insufflation with room air, compared with 11% of patients in whom CO2 was used for insufflation (P = .005). The mean pain score for CO2 was 0.4, and for room air, 1.2 (P less than .005). Although five patients experienced grade 4 pain after insufflation with air, no patient reported severe pain after CO2 insufflation. Post-evacuation films confirmed there was significantly less residual gas in the CO2 group. The quality of radiographs was equal in the two groups. CO2 has advantages for use in the double-contrast barium enema examination.     

Three patients with structurally abnormal X chromosomes, each with Xq13 breakpoints and a history of idiopathic acquired sideroblastic anemia

Structural abnormalities of the X chromosome are rarely found in neoplastic disorders. We describe three patients with a history of idiopathic acquired sideroblastic anemia (IASA); each one had an abnormal clone of cells in the bone marrow, characterized by a structurally abnormal X chromosome. In two of these patients, the predominant karyotype was 47,X,2idic(X)(q13); in the other patient, it was 46,X,t(X;11)(q13;p15). Inasmuch as all three of these cases involved chromosome band Xq13, as did two previously published cases, we suggest that band Xq13 may be more prone to structural rearrangement than other X chromosome bands in hematologic disorders. The common Xq13 chromosome breakpoint and clinical presentation (IASA) among these three patients and the occurrence of an X-linked type of sideroblastic anemia may suggest that an association exists between X chromosome abnormalities and IASA. Perhaps alteration of a gene or chromosome structure in or near band Xq13 predisposes to development of IASA. The fact that two of these patients had preleukemia and the third had overt acute leukemia may imply that patients with IASA and X chromosome abnormalities have a poor prognosis. Cases of IASA without associated X chromosome abnormalities are known; thus, if an association between IASA and an abnormal X chromosome does exist, most likely it involves only some patients with IASA.     

N-(3-acetylaminophenyl)piperazine hydrochloride (BEA 1654), a putative 5-HT1 agonist, causes constriction of arteriovenous anastomoses and dilatation of arterioles

Using 3H-ligands and radioactive microspheres we studied the binding characteristics and the effects on the distribution of carotid arterial blood flow of n-(3-acetylaminophenyl)piperazine hydrochloride (BEA 1654). The compound had a Ki value of 32 nM (5-HT: 8 nM) on 5-HT1 but no or very weak affinity for 5-HT2, alpha 1- and alpha 2-adrenoceptor sites in rat cerebral cortex homogenates. Intracarotid infusions of BEA 1654 (0.1-1.0 mg X kg-1 X min-1) were nearly equieffective in untreated and treated (phentolamine plus ketanserin) pigs in redistributing carotid arterial blood towards the nutrient compartment (particularly the skin and ears) at the expense of shunting via arteriovenous anastomoses (AVAs). In view of the high and selective affinity of BEA 1654 to 5-HT1 binding sites, the similarity of pharmacological responses between 5-HT and BEA 1654, and the ineffectiveness of antagonists of 5-HT2 and alpha-adrenergic receptors to block the AVA constriction and arteriolar dilatation caused by both 5-HT and BEA 1654, we conclude that these effects are mediated by 5-HT1 receptors. The vast difference between the ratios of Ki values for 5-HT1 binding sites and of the pharmacologically effective doses of BEA 1654 and 5-HT suggests that either BEA 1654 may be a partial agonist of 5-HT1 receptors or, while the drug binds with both subsets of 5-HT1 receptors, it is only one type which mediates the pharmacological response.