At a recent NET support group
meeting a question was asked about when NETs were first diagnosed? Upon
researching this question it has been reported that the histology (which is
defined as the study of the form of structures seen under the microscope) was first
seen by Theodor Langhans. Langhans was the first to describe the histology of
the carcinoid tumour in 1868; however Otto Lubarsch has been credited with the
first report of two patients with ileal carcinoid tumours which were discovered
at autopsy in 1888. A German pathologist Siegfried Obendorfer at the University
of Munich, in 1907 created the term “karzinoide” or “carcinoma-like” because their slow growth was considered to be
"cancer-like" rather than truly cancerous, however under the
microscope it did resemble carcinoma. Recognition of the endocrine-related
properties of carcinoid tumours did not happen till much later. Rapport and
colleagues in 1948 isolated and named serotonin which was initially identified
as a vasoconstrictor substance in the serum. Enterochromaffin cells, which give rise to carcinoid tumors, were
identified in 1897 by Nikolai Kulchitsky and their
secretion of serotonin was established
in 1953 when the "flushing" effect of serotonin had become clinically
recognized by Lembeck and confirmed it as the major hormone responsible for
carcinoid syndrome. Carcinoid heart disease was identified in 1952, and
carcinoid fibrosis in 1961.
NET tumours were initially
assessed as carcinoid and these tumours still raise many issues regarding
classification, prognosis and choice of the best therapeutic approach. The
incidence and prevalence of NET seems to have increased in recent years, most
likely due to an improvement in diagnostic techniques, continued research and
clinician awareness.