Reelin and its receptors, VLDLR and ApoER2, in melanocytic nevi.

Reelin is an extracellular signaling protein synthesized by Cajal-Retius cells in utero and early after birth, its presence being signaled in adult life too. Reelin acts on its receptors, VLDLR and ApoER2, acting on cytoskeleton, controlling migration and subsequently positioning and stabilizing the cortical neurons. We investigated the reelin presence and its receptors, VLDLR and ApoER2, in melanocytic nevi considering the neural crest origin of the nevus cells and their migration into skin during embrionary period. Melanocytic nevi present a strict cellular architecture and an increased malignant transforming capacity. We investigated reelin presence in 32 melanocytic nevi (5 junctional, 27 compound or 14 dysplastic nevi and 18 non dysplastic nevi). The assessment of reelin presence was performed by histological semiquantitative criteria. Results showed the presence of reelin in 29 cases (29/ 32). The presence of reelin was elevated in junctional areas as in dysplastic nevi. VLDLR presented positive values in 16 cases (16/ 32) and ApoER2 was weak positive in 7 cases. Reelin or its receptors was peritumorally absent. Our study showed the presence of reelin in nevus cells from cutaneous melanocytic nevi and, in these cells, only the VLDLR receptor was present in half of the cases. The significance of the reelin presence in cutaneous nevus cells may be hypothetically considered correlated with the position maintenance of the nevus cells or migration of these cells in malignant transforming situation. Abbreviations: ApoER2 = apolipoprotein receptor 2, VLDLR = very low density lipoprotein receptor, DAB-1 = DIABLO protein, HMB45 = gene HMB45.

Morphological and immunohistochemical criteria of tissue response to radiotherapy in rectal cancer.

AIM: Given the context that rectal tumours respond to a certain degree to radiotherapy, a necessity arises for estimating a tumour's capacity to react to radiation from the very moment of diagnostic biopsy. MATERIAL AND METHODS: We have histologically and immunohistochemically analysed tissues coming from 52 patients with rectal adenocarcinomas. RESULTS: Of the studied parameters, the ones presenting significant variation under radiotherapy in terms of statistics(p 0.05) were: colloid type (p=0.001), EGFR in the tumour(p=0.00045), EGFR in the normal epithelium (p=0.0017),VEGF in the tumour (p=0.0132) and VEGF in the tumour stroma (p=0.030). CONCLUSIONS: Our study follows the same trends as the medical literature we have consulted regarding the variation of EGFR and VEGF with radiotherapy, and the distinct note of our study relies in the observation that normal stroma in case of rectal tumors also reacts to radiotherapy, sometimes more aggressively than the tumor itself, especially in which concerns the nerve and muscle fibers.

Isolated tuberculous tenosynovitis of the forearm in an immunocompetent patient.

Primary tuberculous tenosynovitis is a rare manifestation of extraspinal musculoskeletal tuberculosis. The diagnosis may be easily delayed because of its nonspecific clinical signs. We report a case of culture-proven tuberculous tenosynovitis of the extensor carpi ulnaris tendon and common extensor tendon in a 68-year-old female without concomitant pulmonary tuberculosis, nor documented immunodeficiency. The diagnosis was initially overlooked due to the lack of appropriate histological and bacteriological analyses and the lesion recurred after surgery. MR imaging represents the most accurate method in making the diagnosis, but has no diagnostic specificity in regard to tuberculosis, therefore surgical biopsy is strongly recommended. The patient had a favorable clinical response after a combination of excision and appropriate antituberculous therapy for sensitive Mycobacterium tuberculosis. We emphasize the need for an increased awareness and high index of suspicion of tuberculosis in all cases of a chronic orrecurrent abscess in the extremities, not only in patients living in endemic areas but also in those who have emigrated from regions with a high prevalence of tuberculosis.

Cellular immune response in atypical tuberculosis diagnosed by PCR in paraffin embedded material.

The aim was to evaluate the cellular immune response in atypical tuberculosis and granulomatous inflammation consistent with tuberculosis (TBC), negative histochemically for acid-fast bacilli and analysed by PCR for Mycobacterium tuberculosis (MT) detection in paraffin-embedded tissue. Thirty six samples of differently localized atypical tuberculous lesions and granulomatous tuberculoid lesions negative for acid fast bacilli and 4 positive cases on Ziehl-Nielsen stain were analysed by PCR for MT detection and were tested immunohistochemically (IHC) for the cellular immune response in the granulomas and perigranulomatous tissue. The samples selected were: 7 pulmonary and 33 extrapulmonary specimens, especially lymph nodes. Histologically, the atypical tuberculous lesions contained supurative necrosis, defective granulomas and cellular polymorphism. The epithelioid cells showed frequent mitoses. The immunoprofile of cells was polymorphous. L26 positive small lymphocytes were found in nodular lymphoid aggregates surrounding granulomas. A significantly increased number of positive UCHL1 cells were found in 33 out of the 40 analysed cases, with a larger percentage of CD4 positive T cells (81.8% of cases). CD44 was positive in multinucleated giant cells (17.5% of cases), epithelioid cells (60% of cases) and lymphocytes (30% of cases). CD68 was localized in multinucleated giant cells and epithelioid cells, in a 4%, respectively 62.5% of cases. The PCR was performed in all 40 cases; the tissue samples were heterogeneous (lung, lymph nodes, lever, nasopharynx, etc.) and needed a good quality extraction of DNA. Performing a control PCR for Beta Globin tested the extraction; a good result was obtained in 31 cases (77.5%); from these, 19 cases had amplification for IS 6110. The cellular immune response in the atypical tuberculous lesions was similar in cases with and without acid-fast bacilli, but positive for PCR. In the most cases with negative PCR reaction, it was due to a deficient fixation of the material. The T lymphocytes were numerous in all types of tuberculous granulomas, with the prominence of CD4 positive subtype. The immunoprofile of the epithelioid cells, positive for CD44 and CD68, presenting frequently mitoses suggests an activate state in a possible relationship to the T-cell-mediated immune response in tuberculosis.

Histopathological aspects of pulmonary carcinoid tumors.

Pulmonary carcinoid tumors are considered low grade malignant tumors, arising from neuroendocrine cells from bronchial mucosa. The small cell proliferation is arranged in small nests or trabeculae, the nuclei are round to oval with finely dispersed chromatin, indistinct nucleoli, small amount of cytoplasm, indistinct borders. Problems of differential diagnosis could appear in distinction with others malignancies like adenocarcinomas, squamous cell carcinomas, lymphomas and others neuroendocrine tumors, especially in the different prognosis and therapeutic approach. We described 15 cases of pulmonary carcinoid tumors diagnosticated by morphologic and immunohistochemical methods.

Morphological and immunohistochemical features of tumor infiltrating lymphocytes (TIL) in carcinomas. Note I.

Some malignant tumours like testicular seminomas and ovarian dysgerminomas or medullar carcinoma of the breast, present an unusually lympho-histiocytic (TIL) rich stroma. Many reports have concluded that the prognosis for these patients is correlated with the intensity of TIL. Recently, some analyses consider that tumour-host interactions have a significant prognostic role in many other neoplasms. The presence of TIL may be a sign of less aggressive behaviour of some epithelial neoplasm like gastro-intestinal, pulmonary, mammary, urinary or cutaneous carcinomas (Wilson et al.). The aim of this study is a morphological and immunohistochemical (IHC) characterisation of the lympho-histiocytic populations of TIL in some gastro-intestinal and mammary carcinomas. The two localisation were chosen for their different contact with the exogene antigens and their possible different type of host's immune response.