Classification of salivary gland tumours - a brief histopathological review

Tumours of the salivary glands display a wide variety of histological appearances, and vary in behaviour from totally benign to high grade and usually fatal malignancies. Over the past 40 years several classification schemes have been proposed, of which the most comprehensive and accurate are those of the Armed Forces Institute of Pathology (AFIP) and the World Health Organization (WHO) which were both revised in 1991. They are readily applicable by practising surgical pathologists, and encompass most of the range of tumours likely to be encountered. If I have a slight preference, it is for the WHO classification which is more concise. This paper briefly discusses each tumour, and highlights the changes from previous classifications, including the proper recognition of several newly described tumours which are distinct clinico-pathological entities. Neither of the new schemes solves every problem, and brief attention is drawn to defects. These are minor, and do not significantly detract from the advantages of both new classifications, which represent a major advance in our ability to understand these often perplexing tumours

Malignant lymphoma of the urinary bladder: a clinicopathological study of 11 cases

Aim—To report the clinical and histological features and outcome of primary and secondary malignant lymphomas of the urinary bladder. Methods—Eleven cases of malignant lymphoma of the urinary bladder were obtained from the registry of cases at St Bartholomews and the Royal London Hospitals. The lymphomas were classified on the basis of their morphology and immunophenotype, and the clinical records were reviewed. Results—There were six primary lymphomas: three extranodal marginal zone lymphomas of mucosa associated lymphoid tissue (MALT) type and three diffuse large B cell lymphomas. Of the five secondary cases, four were diffuse large B cell lymphomas, one secondary to a systemic follicular follicle centre lymphoma, and one nodular sclerosis Hodgkins disease. Four patients with secondary lymphoma for whom follow up was available had died of disease within 13 months of diagnosis. Primary lymphomas followed a more indolent course. In one case, there was evidence of transformation from low grade MALT-type to diffuse large B cell lymphoma. The most common presenting symptom was haematuria. Cystoscopic appearances were of solid, sometimes necrotic tumours resembling transitional cell carcinoma, and in one case the tumours were multiple. These cases represented 0.2% of all bladder neoplasms. Conclusions—Diffuse large B cell lymphoma and MALT-type lymphoma are the most common primary malignant lymphomas of the bladder. Lymphoepithelial lesions in MALT-type lymphoma involve transitional epithelium, and their presence in high grade lymphoma suggests a primary origin owing to transformation of low grade MALT-type lymphoma. Primary and secondary diffuse large B cell lymphomas of the bladder are histologically similar, but the prognosis of the former is favourable. Key Words: bladder • lymphoma • mucosa associated lymphoid tissue lymphom