Jakob Erdheim (1874-1937): father of hypophyseal-duct tumors (craniopharyngiomas).

Jakob Erdheim (1874-1937) was a Viennese pathologist who identified and defined a category of pituitary tumors known as craniopharyngiomas. He named these lesions "hypophyseal duct tumors" (Hypophysenganggeschwülste), a term denoting their presumed origin from cell remnants of the hypophyseal duct, the embryological structure through which Rathke's pouch migrates to form part of the pituitary gland. He described the two histological varieties of these lesions as the adamantinomatous and the squamous-papillary types. He also classified the different topographies of craniopharyngiomas along the hypothalamus-pituitary axis. Finally, he provided the first substantial evidence for the functional role of the hypothalamus in the regulation of metabolism and sexual functions. Erdheim's monograph on hypophyseal duct tumors elicited interest in the clinical effects and diagnosis of pituitary tumors. It certainly contributed to the development of pituitary surgery and neuroendocrinology. Erdheim's work was greatly influenced by the philosophy and methods of research introduced to the Medical School of Vienna by the prominent pathologist Carl Rokitansky. Routine practice of autopsies in all patients dying at the Vienna Municipal Hospital (Allgemeines Krankenhaus), as well as the preservation of rare pathological specimens in a huge collection stored at the Pathological-Anatomical Museum, represented decisive policies for Erdheim's definition of a new category of epithelial hypophyseal growths. Because of the generalized use of the term craniopharyngioma, which replaced Erdheim's original denomination, his seminal work on hypophyseal duct tumors is only referenced in passing in most articles and monographs on this tumor. This article is intended to pay tribute to Erdheim's fundamental breakthroughs, his discovery of craniopharyngiomas and their functional damage to the hypothalamus. On these fundamental achievements, Jakob Erdheim should be recognized as the true father of craniopharyngiomas.