The present study revises the criteria of the Polycythemia Vera Group (PVSG) for the diagnoses of essential thrombocythemia (ET) and polycythemia vera (PV) in view of accumulating data on in vitro cultures of hematopoietic progenitors and by adding histopathology from bone marrow biopsies. The majority of ET patients show spontaneous megakaryocyte or erythroid growth or both, but in about 35% the growth pattern is normal. So far none of the patients with reactive thrombocytosis have shown either spontaneous megakaryocyte or erythroid colony growth. Virtually all PV patients show spontaneous or endogenous erythroid colony (EEC) formation, whereas patients with secondary erythrocytosis and healthy controls do not show any erythroid colony growth in the absence of erythropoietin (EPO). Some rare patients with a disorder other than a myeloproliferative disease (MPD) may show spontaneous growth of erythroid colonies caused by a mutation in the EPO receptor. Megakaryocytes in bone marrow smears and biopsy material from ET and PV patients are typically increased in number and size. Enlarged megakaryocytes with mature cytoplasm and multilobulated nuclei and the tendency of these megakaryocytes to cluster in a normal or slightly increased cellular bone marrow represent the diagnostic hallmark of ET. Increase and clustering of enlarged, mature, and pleiomorphic megakaryocytes in a moderate to marked hypercellular bone marrow with hyperplasia of dilated sinuses is the diagnostic feature of untreated PV. In reactive thrombocytosis and secondary erythrocytosis the size and morphology of megakaryocytes remain normal and there is no tendency of the megakaryocytes to cluster. Both spontaneous EEC and histopathology of bone marrow biopsies appear to offer specific clues to the diagnosis of overt and latent ET or PV and have the potential to differentiate ET from reactive thrombocytosis and PV from secondary erythrocytosis. Moreover, bone marrow histopathology has the diagnostic power to distinguish and to stage the various MPDs without regard to clinical and laboratory data.

Cytology, cytochemistry, immunophenotyping and cytogenetic analysis have specific roles in the diagnosis and management of various haematological neoplasms. Careful examination of Romanowsky-stained films of blood and bone marrow is fundamental in all haematological diagnosis and, when considered together with clinical and haematological features, indicates which of the more specialized techniques are most likely to be useful. The major role of cytochemistry is in the diagnosis of acute myeloid leukaemia and the myelodysplastic syndromes. The major role of immunophenotyping is in the diagnosis of the chronic lymphoproliferative disorders and of acute leukaemia which is not obviously myeloid. Cytogenetic analysis has a role in confirming the diagnosis of chronic granulocytic leukaemia and gives important supplementary information in the acute leukaemias and the myelodysplastic syndromes.

The Association of Directors of Anatomic and Surgical Pathology have developed recommendations for the surgical pathology report for common malignant tumors. The recommendations for carcinomas of the urinary bladder are reported herein.

The Association of Directors of Anatomic and Surgical Pathology (ADASP) has named several committees to develop recommendations regarding the content of the surgical pathology report for common malignant tumors. A committee of individuals with special interest and expertise write the recommendations, and they are reviewed and approved by the council of ADASP and subsequently by the entire membership. The recommendations have been divided into four major areas: (1) Items that provide an informative gross description; (2) Additional diagnostic features that are recommended to be included in every report if possible; (3) Optional features that may be included in the final report; and (4) A checklist. The purpose of these recommendations is to provide an informative report for the clinician. The recommendations are intended as suggestions and adherence to them is completely voluntary. In special clinical circumstances, the original recommendations may not be applicable. The recommendations are intended as an educational resource rather than a mandate.

To evaluate the SIOP protocols in the treatment of mesenchymal tumors.