The term "lymphadenopathy", meaning lymph node disease, is a case in point. In former times, lymph nodes (as they are known now) were known as lymph glands. It was believed that the lymph fluid circulating in the lymph vessels, was produced by the lymph nodes. Organs that produce chemicals that are circulated to other tissues are referred to as glands (e.g., endocrine glands, exocrine glands). Hence the term "lymph gland". A disease of the lymph gland was termed "lymphadenopathy" from lymph + adenos (Greek for gland) + pathei (Greek for disease).
Source: National Cancer Institute, public domain
The term for a neoplasm of a lymph node was "lymphadenoma"
The term for inflammation of a lymph node was "lymphadenitis"
Nearly everything about lymph node pathology was saddled to the ill-conceived notion that a lymph node is a type of gland.
We now know that lymph is not produced by the glandular activity of lymph nodes. Lymph is interstitial fluid (i.e., fluid between tissue cells) that is absorbed into lymph vessels. Lymph fluid is somewhat milky because it contains white cells, sloughed from lymph nodes, but the fluid comes from tissue interstitium and its composition is akin to blood plasma.
Modern pathologists have dropped the "adeno" in "lymphadenoma" and replaced it with the less confusing term, "lymphoma".
Regrettably, the terms "lymphadenopathy" and "lymphadenitis" persist into modern usage.
- Jules J. Berman, Ph.D., M.D. tags: lymph node, lymphoid, lymphedema, lymphatics, lymphatic vessels, common disease, orphan disease, orphan drugs, rare disease, subsets of disease, disease genetics, logophile, medical terminology, medical nomenclature, medical dictionary
In June, 2014, my book, entitled Rare Diseases and Orphan Drugs: Keys to Understanding and Treating the Common Diseases was published by Elsevier. The book builds the argument that our best chance of curing the common diseases will come from studying and curing the rare diseases.
I urge you to read more about my book. There's a generous preview of the book at the Google Books site. If you like the book, please request your librarian to purchase a copy of this book for your library or reading room.