Nestin and caveolin-1 in the diagnosis of GISTs.

Gastrointestinal stromal tumors (GISTs) are the most common primary mesenchymal neoplasias of the gastrointestinal tract, typically expressing c-kit (CD117) and CD34. Recently, it was reported that nestin and caveolin-1 are also expressed in some human sarcomas, GISTs included. We performed a retrospective study on formalin fixed, paraffin embedded samples from 81 cases of confirmed GISTs, aiming to characterize their immunohistochemical profile, including nestin and caveolin-1 expressions. Tissue samples were evaluated immunohistochemically for CD117, CD34, nestin and caveolin-1. The patients (M:F 36:45), aged 46 to 84 years, had spindle cell type GISTs in 56.7% of cases, epithelioid in 30.8% and mixed pattern in 12.3%. Immunohistochemically, CD117 was positive in 88.9% of GISTs, CD34 in 85.1%, nestin in 77.7% and caveolin-1 in 71.6% of the tumors. Of nine c-kit negative GISTs, 66.7% expressed nestin, the same as caveolin-1 and 44.5% expressed both nestin and caveolin-1. Statistical analysis using Kendall's and Spearman's tests revealed significant correlations between nestin and caveolin-1 expressions (p=0.024). Our results suggest that nestin and caveolin-1 could be considered sensitive markers in GISTs, together with CD117 and CD34, for diagnostic purposes. Their significant expression in CD117 negative GISTs could represent an immunohistochemical alternative in establishing the diagnosis of these tumors.

Rare renal tumor--mucinous tubular and spindle cell carcinoma.

We report a rare case of renal tumor--mucinous tubular and spindle cell carcinoma in a 65-year-old man. The tumor, located in the right kidney, was well circumscribed. Microscopically, the tumoral proliferation was composed of cuboidal cells arranged in tubules, with abrupt transition to spindle cell morphology in a myxoid stroma. Because of the favorable prognosis with this type of tumor, mucinous tubular and spindle cell carcinoma must be differentiated from papillary renal cell carcinoma, especially the variant with sarcomatoid dedifferentiation.

Primary varices pathogenesis. The appealing unitary model.

Primary varices pathogenesis is still unclear about the trigger event and the disease progression. Throughout time, a lot of hypotheses were created, each with a certain degree of veracity, to explain the aforementioned dilemmas. Present day investigation technologies allowed the undeniable progress in deciphering venous mechanics and biochemistry. Objectifying venous hemodynamic and valvular-parietal changes, their dynamic progression as well, lead to important clarifications in primary varicose disease physiopathogenesis. The importance of establishing a complete, unitary pathogenic model implies the practical possibility of immediately applying the right therapy addressing the pathogenic mechanism of this disease (i.e. correcting the "pressure escape" gateway) correlated with the progression stage (reflux degree) and the type of primary varices (gravitational, non-gravitational, or "suspended" varices). Initially, our study produces a critical evaluation of the classic pathogenic hypotheses and, later on, based on our long time experience in this field, it presents a complete and unitary, evolutive and pathogenic model in primary varices. The proposed model details a pathogenesis and a progression far more nuanced in primary varices, based on solid evidence, having obvious therapeutic implications and predictable results.

Prognostic and predictive significance of the bcl-2/IgH translocation in malignant follicular lymphomas.

BACKGROUND: The t(14;18) translocation, which leads to an overproduction of the bcl-2 protein, supposedly occurs in almost all follicular lymphomas (FL) and can be detected by FISH methods or by PCR. Its detection is useful in monitoring the response to therapy and in assessing minimal residual disease in bone marrow. Recently it was observed that the translocation could become negative after treatment. The prognostic and predictive significance of this fluctuation is not entirely understood. AIM: We intended to find significant correlations among morphological features, histological grades, immunohistochemical findings, and cytogenetical aberrations in malignant follicular lymphomas, in order to identify the prognostic and predictive value of the bcl-2/IgH translocation in these malignancies. MATERIAL AND METHODS: We conducted a study on 79 patients with follicular lymphomas. The study was carried out on tissue samples selected from the "Victor Babes" National Institute of Pathology files. These samples were tested by immunohistochemistry and FISH. RESULTS: Most of the cases (65.2%) were low-grade FL (grade 1-2). Approximately 58.8% of cases in the FISH study group presented t(14;18). In 66.6% of the cases with t(14;18), the immunohistochemical reaction for bcl-2 protein was positive. A significant positive correlation was found between the IHC positivity for bcl-2 and t(14;18) detected by FISH (p=0.04). CONCLUSIONS: Bcl-2 t(14;18) plays an important role in the pathogenesis of follicular lymphoma. FISH is an important tool in the diagnosis, treatment and follow up of these malignancies, since the immunohistochemical testing is negative in a significant proportion of cases.

The valvular segment of the lower limbs venous system: anatomical, physiological and physiopathological aspects.

The valvular segment is a distinct venous structure, which, from a morphological point of view, is comprised of the following components: the valvular insertion, the valvular gorge entrance orifice, the valvular defile, the valvular gorge exit orifice, the valvular sinus. Endoscopic and echo Doppler examinations are used to identify the normal and the pathological morphology of the valvular segment, and the hemodynamic phenomena occurring at this level. Cusps' integrity and size as well as valvular dynamics are key elements directly involved in shaping the valvular segment in general, and the valvular sinus in particular. The valvular sinus shows an obvious hemodynamic determinism. Valvular segment pathology is the outcome either of a progressively long evolving process initialized by gravitational venous pressure overcharges, or of a rapidly evolving process such as the hemodynamic shock following intense physical efforts. Valvular defunctionalisation implies a different mechanism and a different type of cusp lesion.