Primary angiomatoid melanoma as an exceptional morphologic pattern in cutaneous melanoma. A case report and review of the literature.

We report a case of angiomatoid melanoma on the right thigh of a 59-year-old man. The histologic growth pattern of the tumor mimicked vascular proliferation, and the cells lining the pseudovascular spaces were positive for protein S-100, HMB-45, and MITF-1. The differential diagnosis is with angiosarcoma and pseudovascular adenoid squamous cell carcinoma. The case we present is the fifth reported to date.

[Multicentric inflammatory pseudotumor with asynchronic presentation in meninges, liver, spleen and lymph nodes in a patient with seronegative spondiloarthropathy. Case report and review of the literature]. / Pseudotumor inflamatorio multicéntrico con presentación asincrónica en meninges, hígado, bazo y ganglios linfáticos en una paciente con espondiloartropatía seronegativa. Presentación de un caso y revisión de la bibliografía.

INTRODUCTION: Inflammatory pseudotumor is a reactive process in which the etiology and pathogenesis are not well defined, that can be found in any location. The cases with central nervous system affection have been described in meninges, brain, choroid plexus and cranial and spinal nerves. Multicentric cases, synchronous and asynchronous have been described. CASE REPORT: A 45 years-old woman with a rheumatologic disease (a seronegative spondiloarthropathy) who developed an inflammatory pseudotumor in spleen, liver and abdominal lymph nodes in 1995, associated to fever of unknown origin, six years later she presented with an inflammatory pseudotumor of the meninges in the convexity of the right frontoparietal region, with fever, malaise, and increase of globular sedimentation rate, microcytic hypochromic anemia and thrombocytosis. CONCLUSION: The clinicopathologic features of this lesion are revised, including the different theories in regard to the etiology and pathogenesis, and the role of cytokines produced by inflammatory cells in the tumor.

[Diagnosis of early gastric marginal zone lymphoma (MALT lymphoma) in endoscopic biopsies. Report of a case that demonstrates the utility of immunohistochemistry and the molecular analysis.]. / Diagnóstico del linfoma de la zona marginal (linfoma MALT) gástrico temprano, en biopsiasendoscópicas. Informe de un caso que ilustrala utilidad de la inmunohistoquímica y el análisis molecular.

MALT lymphomas are a subtype of low grade lymphomas that represent 7-8% of all B-cell lymphomas originated in extranodal sites. Nearly 50% of the cases present as primary gastric lymphomas.They arise from the acquired MALT developed during the course of H. pylori chronic infection. Microscopically,the presence of lymphoid follicles with follicular colonization, marginal zone ("centrocytoid")cells and lymphoepithelial lesions is characteristic.Histopathological diagnosis may result difficult in superficial endoscopic biopsies showing a typical lymphoid infiltrates. Using Wotherspoon criteria along with molecular analyses is useful in borderline lesions. We present the case of a 62 years old female with chronic gastritis. A small endoscopic biopsy was performed and the presence of a heterogeneous lymphoid infiltrate in the lamina propia was observed. Immuno histochemical profile showed focal co expression of CD20 andCD43 and kappa light chain restriction. The diagnosis of an atypical lymphoid infiltrate highly suspicious of MALT lymphoma was established. PCR molecular analysis corroborated the monoclonal pattern of the lymphoid cells and the diagnosis of lymphoma. Immunohistochemical and molecular analyses in cases of lymphoid infiltrates suspicious of malignancy (Wotherspoon 3 and 4) will aid in the adequate diagnosis between chronic gastritis and MALT lymphoma, which is crucial for prognosis,treatment and patient's outcome.Key words: Chronic reactive gastritis, marginal zone lymphoma, MALT lymphoma, gastriclym.

[José Verocay. Verocay neurinomas and bodies and other contributions to medicine]. / José Verocay. Neurinomas y cuerpos de Verocay y otras contribuciones a la medicina.

AIMS: To describe the academic contributions to pathology and the biography of José Verocay (1876-1927), and to comment on the differential diagnosis of Verocay bodies. DEVELOPMENT: José Juan Verocay was an Uruguayan-born pathologist that worked at the Institute of Pathology in Prague under the figures of Chiari, Kretz and Ghon. He described in 1910 the structures today known as 'Verocay bodies', in a paper on neurofibromas. During some time, schwannomas were known as 'neurinomas of Verocay'. This peculiar alienation of cells of Schwann known as Verocay bodies, is characteristic, but not exclusive of schwannomas, and may be found in other mesenchymal tumors, some carcinomas and in melanomas.

[Paraganglioma of the cauda equina with papillary pattern and cytokeratin expression: 2 potential sources of diagnostic error. Report of a case and review of the literature]. / Paraganglioma de la cola de caballo con patrón papilar y expresión de citoqueratina: dos causas potenciales de error diagnóstico. Reporte de un caso y revisión de la literatura.

UNLABELLED: Paragangliomas are unusual neuroendocrine tumours, rare in the cauda equina and filum terminale. Due to their low frequency, no classical patterns and dual immunophenotype, may be misinterpreted as others neoplasms more frequent in this site. It is our aim to report a case of paraganglioma of the cauda equina and filum terminale (PGCCFT), standing out it's histological-immunohistochemical pattern, differential diagnosis, prognostic and treatment. We reviewed the clinical presentation, NMR features and morphological aspect of one PGCCFT, diagnosed in the ABC Medical Center's Surgical Pathology Department of Mexico City. Report of the case: 26 years old man, who had been suffering a low lumbar pain for one year before he came to our hospital. The NRM showed heterointense lesion in the level of first and second vertebra, suggesting ependymoma. The tumor was totally resected. Histologically it was papillary, the chief cells have stained with chromogranin, synaptophysin, and cytokeratin. The few sustentaculars cells were S100 positive. The patient have haven a favorable course. CONCLUSIONS: The certainty and differential diagnosis of paragangliomas of the cauda equina and filum terminale needs correlation between histological pattern and immunophenotype, the last must be considered in the peculiar context of this anatomic region.

[Biomarkers in breast cancer with high over-expression of HER2 protein]. / Marcadores biológicos en carcinomas mamarios con alta sobreexpresión de proteína HER2.

INTRODUCTION: The predictive value of the HER2 protein over-expression in order to the breast carcinomas response to dexorubicin and Herceptin therapy has been proved. DAKO Herceptest pretend to be a tool in the identification of patients for whose Herceptin might be an option. In one breast carcinoma serie studied in our laboratory we detected a high over-expression of HER2. Only four cases were recurrent tumors. OBJECTIVE: To characterize the breast carcinoma serie assayed with DAKO Herceptest by the expression of other prognostic or predictive markers (hormone receptors, Ki-67, p53, tumoral ploidy) that are routinely tested in our laboratory. MATERIAL AND METHODS: 97 consecutive mammary carcinomas recieved between July and October, 2000 in the ABC Medical Center's Surgical Pathology Department of Mexico City, were analyzed with DAKO Herceptest, and for estrogen/progesterone receptors, p53, Ki-67 and tumoral ploidy. RESULTS: We found HER2 over-expression in 46.3% of the cases tested. The 47.6% of this subgroup showed hormone receptors negative immunophenotype, 89.7% high cellular proliferation index (Ki-67), 72.5% of p53 expression, and tumoral aneuploidy in 72.9%. CONCLUSIONS: The high expression of desfavorable prognostic and/or predictive factors for mammary carcinomas in the casuistic, suggest that the population in study have a particularly aggressive phenotype, where the over-expression of HER2 protein results in concordance and it is not related with tumoral relapse.

[An atypical rhabdoid/teratoid tumor. A presentation of three cases and review of the literature]. / Tumor rabdoide/teratoide atípico. Presentación de tres casos y revisión de la literatura.

INTRODUCTION: The atypical rhabdoid/teratoid tumor of the central nervous system (CNS) has emerged from a variant of medulloblastoma to become a distinctive clinico-pathological condition over the past ten years. This is more than simply nosological importance, since the five year survival expected in medulloblastomas is considerably better than the 11 months (average) seen in rhabdoid/teratoid tumors. OBJECTIVE: To describe the main clinico-pathological characteristics of a recently recognized condition, emphasizing its polymorphism and differential diagnosis. PATIENTS AND METHODS: We report the clinical, radiological, cytohistopathological and immunohistopathological aspects of three atypical rhabdoid/teratoid tumors diagnosed in the Hospital A.B.C. of Mexico City. RESULTS: The three tumors were seen in boys aged 18 months, 5 years and 14 years, localized to the right cerebellum, left cerebral hemisphere and left cerebellum, respectively. Different markers were shown including: vimentin, cytokeratin, epithelial membrane antigen, gliofibrillare acid protein, synaptophysin, alpha fetoprotein, S100, (HHF-35) actin, cromogranin, neurofilaments, human chorionic gonadotrophin, placental alkaline phosphatase, desmin, CD99 and carcinoembryonary antigen. We established the morphological similarities and differences in our cases, and noted the profuse vascular proliferation which in one case resembled vascular neoplasia. We compared our results with other published cases. CONCLUSIONS: The atypical rhabdoid/teratoid tumor of the CNS may easily be confused with other primary or metastatic tumors since the rhabdoid characteristics do not only occur in this tumor. Also the rhabdoid aspect may be less marked and in some cases does not predominate. Some zones of the tumor may be identical to other embryonic tumors of the CNS and the immunophenotype be superimposed on that of other neoplasias of the nervous system.

Stromal tumor of the gallbladder with phenotype of interstitial cells of Cajal: a previously unrecognized neoplasm.

We report a small, well-demarcated stromal tumor of the gallbladder in a 69-year-old woman. The tumor and associated cholelithiasis led to chronic cholecystitis symptoms. The wall of the gallbladder contained a 2.4-cm hypocellular nodule composed of bland spindle-shaped cells that were immunoreactive for vimentin, CD34, and CD117. With the latter antibody, which stains interstitial cells of Cajal (ICC), the neoplastic cells appear fusiform with elongated bipolar projections or dendritic-like cytoplasmic projections. The gallbladder wall adjacent to the tumor contained numerous CD117-positive cells in close contact with the normal smooth muscle cells, whereas two of 10 gallbladders with minimal chronic cholecystitis showed only a few CD117-positive cells. These findings provide evidence that this stromal tumor of the gallbladder shows ICC differentiation similar to some stromal tumors of the gut. The presence of numerous ICC in the uninvolved gallbladder wall suggests that this tumor might have evolved through hyperplasia of ICC.

[Atypical regenerative changes, dysplasia, and carcinoma in situ in chronic gastritis associated with Helicobacter pylori]. / Cambios regenerativos atípicos, displasia y carcinoma in situ en gastritis crónica asociada con Helicobacter pylori.

In the present work we study the association between chronic active gastritis (CAG), atypical regeneration and dysplasia and gastric Helicobacter pylori (HP) infection. We study two groups of endoscopic biopsies. Regenerative changes and dysplasia were evaluated according to Gandur-Maymneh et al. classification which was simplified in typical and atypical regeneration, and mild and severe dysplasia. The group I included 94 patients with CAG, 9 with chronic non active gastritis (CNAG) and 2 with normal gastric mucosa. CAG was graded according to activity in; severe 28 patients; moderate 54 patients and; mild 12 patients. HP association in these cases was 100%, 77% and 25%. In cases of CNAG HP was present in 22%, there were not HP in normal gastric mucosa. There were atypical regeneration in 25% of moderate CAG and in 42% of severe CAG. Mild dysplasia was present in 7.5 and 25% in cases of moderate and severe CAG. Two biopsies showed severe dysplasia. In addition, intestinal metaplasia was found in 15% of CAG, the metaplasia was present in 25% of cases with CAG and atypical regeneration; in 54% of cases with mild dysplasia and; in 100% on cases with severe dysplasia. The group II included 9 cases of gastric cancer of intestinal type, 7 cases of diffuse type, and 4 cases of mixed type. In all these cases there was viewed CAG associated to HP infection in non-neoplastic mucosa. In 75% of cases there were showed atypical regeneration and 60% presented some type of dysplasia. There was transition between atypical regeneration and dysplasia in 6 cases of intestinal gastric cancer and in 3 cases of mixed type. We found relationship between the intensity of CAG and HP colonization, and the association with atypical regeneration and dysplasia.

[Diffuse myometrial hypertrophy. Cause of abnormal uterine bleeding. Clinico-pathological study of 4 cases and review of the literature]. / Hipertrofia difusa del miometrio. Causa de sangrado uterino anormal. Estudio clinicopatológico de cuatro casos y análisis de la literatura.

Difusse uterine myohipertrophy (DUMH) is a condition characterized by the presence of homogeneous and diffuse uterine enlargement in the absence of myoendometrial cause of bleeding. Today there is insufficient data to conclude that DUMH is a distinct clinicopathological entity. It is characterized by: 1) Uterine weight of more that 200 g, 2) a myometrial thickness of more that 2.0 cm and 3) the absence of any endomyometrial cause of bleeding. In DUMH the increased thickness of the myometrium is due to hypertrophy of the muscle cells with no increase in fibroconnective intersticial tissue and the bleeding secondary to increase endometrial area and abnormal myometrium contraction. We report 4 cases of DUMH seen at the ABC Hospital.

High prevalence of a 30-base pair deletion in the Epstein-Barr virus (EBV) latent membrane protein 1 gene and of strain type B EBV in Mexican classical Hodgkin's disease and reactive lymphoid tissue.

Depending on geographic location and patient age Hodgkin's disease (HD) is associated with Epstein-Barr virus (EBV), mostly type A EBV, in 20% to 100%. The highest prevalence occurs in children of developing countries. Molecular analysis of the oncogene coding for the latent membrane protein 1 (LMP-1) revealed a 30-base pair (bp) deletion in up to 46% of EBV-positive HD. We investigated the presence of EBV in a series of Mexican classical HD (n = 57) and reactive lymphoid tissues (n = 20) from a private and a public hospital with special emphasis on the prevalence of the 30-bp deletion and the type of EBV. EBV infection was analyzed at the cellular level by Epstein-Barr encoded early RNA transcripts (EBER) in situ hybridization (ISH) and by LMP-1 protein immunohistochemistry (IHC). Molecular analysis of the LMP-1 gene configuration was performed by polymerase chain reaction (PCR) with primers spanning the site of the deletion and subsequent Southern and/or dot blot hybridization using wild-type and deletion-specific probes. The prevalence of type A and type B EBV was investigated by PCR-analysis for divergence in the coding region of Epstein-Barr nuclear antigen (EBNA)-2. EBV was detected in Hodgkin- and Reed-Sternberg cells (H-RS) by LMP-1 IHC and/or EBER ISH in 35/57 (61%) Mexican HD including 18/32 (56%) with nodular sclerosis, 15/20 (75%) with mixed cellularity and 2/4 (50%) with lymphocyte depletion. In addition, LMP-1 gene sequences were detected by PCR in 9 cases of HD without LMP/EBER expression by H-RS cells and in 17/20 (85%) reactive lymph nodes, supposedly originating from rare latently infected B cells. Surprisingly, the 30-bp LMP-1 deletion was found in 28/35 (80%) EBV-positive HD. This deletion, however, was also found in all 9 (100%) HD with H-RS cells negative for EBV and in 10/17 (59%) reactive lymph nodes. Thus, the overall LMP-1 del prevalence in reactive tissue is 73% (19/26). Typing of EBV was successful in 26 cases of EBV-positive HD, 10 of these were infected by type B EBV (38%). Of the reactive lymphoid tissue, 9 (47%) were infected by type A, and 10 (53%) by type B; All 20 cases (100%) associated with type B, whether neoplastic or reactive, displayed the LMP-1 del variant compared with 18/25 (72%) infected by type A EBV. To our knowledge, this is the highest incidence for both the LMP-1 deletion variant and the infection by type B EBV in HD reported so far worldwide. Our data suggest that EBV infection contributes to the pathogenesis of the majority of Hodgkin's disease cases in Mexico. The specific tumorigenic role of the LMP-1 deletion variant, however, is doubtful with regard to its high frequency in nonneoplastic lesions. Moreover, type B infection frequently occurs in Mexican HD and reactive lymphoid tissue and is consistently associated with the deletion variant pointing to a pathogenetic role of this combined genotype.

[CD-34 expression in elastofibroma. Clinicopathological, histochemical, and immunohistochemical study of four cases]. / Expresión de CD-34 en el elastofibroma. Estudio clinicopatológico, histoquímico e inmunohistoquímico de cuatro casos.

OBJECTIVE: To explore the immunohistochemistry of elastofibromas and to evaluate four elastic strain methods for the histological diagnosis of elastofibroma. MATERIAL AND METHODS: Four elastofibromas were obtained from the surgical pathology files of the ABC Medical Center. All patients were women whose lesions were present in the subescapular region. Immunohistochemistry was performed for CD34, actin, desmin, vimentin, S-100 protein and bcl-2 and four elastic stain methods were evaluated (Verhoff, Gallego's, Reyes-Mota and Russel-Movat). RESULTS: In the four cases there were numerous miofibroblasts (vimentin/actin/desmin positive). An unpreviously reported positive CD34 dendritic cells, were present diffusely in all four cases. Verhoff and Reyes-Mota stains remains the most useful methods to reveal the elastic fibers. Russel-Movat method may be use to contrast different connective tissue components. CONCLUSION: The cell of elastofibromas were originally considered fibroblasts. The presence of actin/desmin/vimentin suggests that they are miofibroblasts. We describe for the first time, variable numbers of CD34(QBend/10) positive spindle shaped and dendritic cells in all elastofibromas. These cells may be a reactive population of cells of the "dendritic cell system". There was no immunoreactivity for bcl-2 in these cells.