The entity 'angioendotheliomatosis proliferans systemisata' was first described 28 years ago as a cutaneous small vessel neoplasm of presumed endothelial origin. Since then, 101 similar cases have been reported under a variety of different names, most with systemic as well as cutaneous lesions, and a lymphoid histogenesis of the tumour cell is now favoured. Review of these cases has shown a characteristic clinical presentation with predominant neurological and dermatological features, although the diagnosis was made at autopsy in 53 per cent of patients. Most therapeutic regimens have proved ineffective with a median survival of 5 months from date of clinical presentation. Aggressive combination chemotherapy can produce complete and lasting remission and a partial response to steroids is sometimes seen. We have examined a case of this condition showing unusual clinical features. Immunohistochemical studies confirm the lymphoid origin of the tumour cells with B cell phenotype. Antigen receptor gene rearrangement studies indicate the presence of the same clonal population of B cells in multiple sites. We suggest that the term 'angioendotheliomatosis proliferans systemisata' should be dropped and support the use of 'angiotropic large cell lymphoma' to describe this unusual condition.

B-Lymphocytes↗

PubMedDate not supplied

Radiolabeled octreotide. What lessons for antibody-mediated targeting?

Octreotide is a synthetic analog of the peptide hormone somatostatin (SMS). A wide variety of tumors express enhanced numbers of SMS receptors, notably neuroendocrine tumors and lymphomas, but also some of the more common adenocarcinomas. Octreotide contains only eight amino acids, some of which are in the (D) configuration in order to enhance the stability of the molecule in vivo. Tyrosine and DTPA-containing analogs of octreotide have been synthesized and labeled with iodine-123 and indium-111, respectively, with the intention of targeting SMS receptor-containing tumors for diagnostic purposes. Both radiopharmaceuticals demonstrate a high sensitivity and specificity for these tumors, indicating a clinical role for these agents in management of these diseases. Lessons can be learned from the success of these agents when designing improved antibody-based molecules. Tumor uptake of radiolabeled octreotide is very rapid, occurring within minutes of administration. Blood clearance is also rapid, such that tumors are soon visible even in areas of high blood background. An interesting finding has been the differences between the pharmacokinetics of the iodinated and indium-labeled species. Although the majority of 123I-Tyr3-octreotide undergoes hepatobiliary excretion, 111In-DTPAPhe1-octreotide is eliminated predominantly by the kidneys. These results suggest that the smallest possible antibody-like tracers are likely to have advantages over native immunoglobulins and conventional Fab-like fragments.

Adenocarcinoma↗

PubMedDate not supplied

[The interaction of chlordiazepoxide and dexamphetamine in man].

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Adult↗