Pathology of XXXX : anything new?

@entity1 @entity9712 @entity2033 @entity4383 @entity1893 @entity978
This presentation deals with the gross and microscopic pathology of @entity2033 . Recent advances in immunohistochemistry, gene rearrangement studies and cell culture are not discussed, except where they shed light on the pathology. Clinical and pathological experience, over the past 2 decades, suggests that @entity2033 should be divided into six subtypes, as originally proposed by Lukes et al. (1966b), rather than the four subtypes included in the Rye classification. Nodular lymphocyte/histiocyte predominant @entity2033 forms a clinicopathological entity separate from the other subtypes. It most frequently presents at a single nodal site and, even without therapy, progresses only slowly over a period of many years. A proportion of the @entity1 (in the region of 10%) develop large cell @entity1893 and a smaller number develop other types of @entity978 . This progression is not due to therapy since it most frequently occurs in untreated @entity1 . Characteristic polylobated @entity9712 cell variants are seen in NLPHD. These differ from classic @entity9712 cells in that they have a B-cell phenotype, they do not show light chain restriction and, therefore, they do not appear to be a clonal proliferation. Although current dogma states that classic @entity9712 cells must be identified before a diagnosis of @entity2033 , including NLPHD, is made, it is the author's contention, supported by immunohistochemistry, that this type of @entity9712 cell does not occur in NLPHD. Polylobated @entity9712 cell variants in the appropriate cellular setting are, in themselves, diagnostic of NLPHD. They also serve to differentiate NLPHD from progressive transformation of germinal centres, an unusual proliferative expansion that may occur in association with @entity2033 but which, in itself, appears to be an entirely benign, reactive process. Diffuse lymphocyte/histiocyte predominant @entity2033 (DLPHD) differs from NLPHD in its diffuse growth pattern and the frequent presence of larger numbers of histiocytes. Polylobated @entity9712 cells are characteristic of both diseases. In some biopsies nodular and diffuse areas are seen in the same lymph node. Despite these similarities, the two diseases differ clinically (NLPHD is usually stage 1, DLPHD is frequently of a higher stage) and in their immunohistochemistry (fewer @entity9712 cell variants in DLPHD contain J-chain than in NLPHD). The reasons for these differences are not apparent and require further investigation. It may be due, at least in part, to the inclusion of cases of MCHD and @entity1893 in the DLPHD category. @entity4383 is the commonest category of @entity2033 in most reported series.(ABSTRACT TRUNCATED AT 400 WORDS)
