No abstract

Twenty hamartomas of the spleen were studied by histological, immuno- and enzyme-histochemical methods. In all cases nodules of varying size resembling proliferation of splenic red pulp structures were present that exhibited considerable morphological variation with regard to plasmacytosis, extramedullary haematopoiesis and phagocytic activity of macrophages. Splenic red pulp structures could be identified by immuno- and enzyme-histochemical markers reacting with sinus endothelium, including Factor VIII related antigen, proteinase inhibitors and non-specific esterases. In conjunction with the absence of organized lymphoid tissue and of dendritic reticulum cells these studies allow the differentiation of splenic hamartomas from haemangiomas that may possess a deceptively similar morphological appearance.

Two patients are presented with primary low grade pleural B cell lymphomas with no history of a pyothorax.P leural disease in non-Hodgkin's lymphoma is well documented and commonly presents with pleural effusions in 20% of patients. 1 However, solid pleural involvement is less common and is usually a secondary event. Primary pleural lymphomas are extremely rare and, in a series reported by Burgener and Hamlin, pleural plaques were seen in less then 4% of cases. 2 Two types of primary pleural lymphomas have been described-the body cavity based lymphoma in patients with HIV and the pyothorax associated pleural lymphoma in those with tuberculosis. Primary pleural non-Hodgkin's lymphoma in an immunocompetent patient without a history of chronic pyothorax is extremely rare. CASE HISTORY 1A 59 year old man presented with a 4 month history of gradually increasing shortness of breath and left sided chest pain. He was a non-smoker with a history of occupational exposure to asbestos (he had worked in power stations for over 30 years). On examination, air entry over the left side of his chest was diminished.Investigations showed a normal full blood count, urea and electrolytes. His chest radiograph revealed a left sided pleural effusion. A chest drain was therefore inserted and approximately 7 litres of serous fluid were drained. A computed tomographic (CT) scan of the thorax showed a left pleural effusion with irregular thickening of the adjacent parietal pleura, extending medially to displace the aorta. Bilateral pleural calcification suggestive of asbestos exposure was also seen. No significant lymphadenopathy was noted. A bone marrow biopsy performed during this admission did not show any evidence of lymphoma. Video assisted thoracoscopy showed diffuse involvement of the parietal pleura from which biopsy samples were taken. Light microscopy showed lymphoid infiltration with a hint of nodularity. Isolated reactive germinal centres were buried within the infiltrate of medium sized lymphoid cells and mononuclear blasts (fig 1). Mitotic figures were easily visible. Immunohistochemical staining confirmed the dominant B cell nature of the infiltrate. The phenotype of the B cells was confirmed as CD43, CD23 and BCl-2 positive, and CD5 and CD10 negative. Follicular dendritic cells in lymphoid nodules were highlighted with CD23 and CD21, confirming follicular colonisation. Ki67 labelling was observed in 30% of the tumour population. These findings supported a diagnosis of low grade marginal zone lymphoma of the pleura. Also present in the sample were hyalinised plaques infiltrated by lymphoma on one surface.DNA was extracted from paraffin embedded material and PCR was performed by standard methods using primers for the FR2 and FR3 regions of immunoglobulin heavy chain.This showed a band, in keeping with the monoclonal nature of the disease. Pleurodesis with 5-fluorouracil was performed and the chest drain was eventually removed. The patient was treated with chlorambucil. Follow up at 18 months showed no evidence of lymphadenopa...

There is a great need to establish reproducible methods for evaluative studies of wound treatment and wound healing. Validation of the healing process through optical techniques, as well as histologic and immunohistochemical methodologies, have been improved and to some extent have become well-established assays. Data relating to biomechanical properties, e.g., evaluation of the tensile strength of scar tissue that forms in experimental wound treatment strategies, are less widely available. We chose the domestic pig as an animal model in which to examine epidermal wound healing. We implanted specially made chambers that served to isolate the wounds and prevent epidermal migration from the edges. We performed histologic and immunohistochemical analyses as well as evaluation of biomechanical qualities of scar tissue using laser tensiometry. Pig skin is well suited for wound healing studies, and wound creation, implantation of the chambers, and the regular changing of dressings could all be carried out in the operating theater. In addition to established macroscopic evaluation and microscopic documentation, the need for objective biomechanical assessment of scar tissue by measuring tensile strength has been met using laser tensiometry. By optimizing methods for measuring tensile strength, it is possible to evaluate the biomechanical quality of scar tissue formed following different courses of wound treatment, as well as histologic assessment.