Pathologists have been accused of having a food fixation when it comes to many of our descriptive terms such as "nutmeg liver," "strawberry gallbladder," "bread and butter pericarditis," "oat cell carcinoma," "coffee bean nuclei," etc. Nonetheless, these descriptive terms do an excellent job of conveying their intended meaning and they've hung around for a long time.
However, some of our nomenclature over the years has been decidedly wrong headed, and although many of these bad terms have fallen by the wayside, many are still around. As examples of bad diagnostic terminology that has almost completely disappeared, I would offer the following examples:
1. Benign fibrous mesothelioma. They're fibrous, usually but not always benign, but they have nothing to do with mesothelium. It's better to call them solitary fibrous tumors.
2. Intravascular bronchioloalveolar tumor (IVBAT) and sclerosing epithelioid cholangiocarcoma. Wrong on both counts. These are both now known to be epithelioid hemangioendotheliomas.
3. Malignant angioendotheliomatosis. Contrary to initial belief these are not tumors of endothelial cells, they're intravascular lymphomas.
4. Leiomyoblastoma. We now know that these gastric tumors are better interpreted as GIST's.
5. Minute pulmonary chemodectomas. These aren't paragangliomas, they're meningothelial-like nodules.
There are other terms that we all know are bad and are decreasing in usage, but they still manage to hang on by the weight of their accumulated literature and the information they convey to clinicians. I few more examples from this group:
1. Malignant fibrous histiocytoma. We got the malignant part right, but they're seldom very fibrous and have nothing to do with histiocytes, though they may occasionally stain for CD68. This is the default pattern for high-grade sarcoma. The much better term of "undifferentiated pleomorphic sarcoma" should replace MFH ASAP.
2. Lymphoepithelioma. When this term was developed both the epithelial and lymphoid components were thought to be malignant. Undifferentiated carcinoma, lymphoepithelioma type, is a better term.
3. Hemangiopericytoma. Sorry Dr. Stout, but most things called this are solitary fibrous tumors or perhaps malignant tumors (ie. synovial sarcoma, mesenchymal chondrosarcoma, etc.) with a non-specific pericytic pattern. Tumors with true pericytic differentiation, encountered mainly in the head and neck, should be termed "glomangiopericytomas."
And finally, there are those truly awful designations that still keep popping up in pathology reports and the literature, and show no signs of dying out. A few examples from this group include:
1. Pyogenic granuloma. Wrong on both counts. These are not pyogenic and not granulomatous. This term gets used for two unrelated lesions, granulation tissue, and lobular capillary hemangioma.
2. Synovial sarcoma. This one isn't going anywhere, but we all know the tumor has absolutely NOTHING to do with synovium, though vanishingly rare intra-articular examples have been reported.
3. Nodular fasciitis and other forms of fasciitis. Not a terribly bad term but in spite of the "itis" designation, this is not an infectious or a primarily inflammatory process, at least in the conventional sense.
4. Carcinoma in-situ. Is it really carcinoma if it's still in-situ and incapable of spreading? ..nuff said. This one has gotten us into lots of trouble and continues to do so. See our earlier breast cancer discussions.
These lists are but the mearest appetizers of the bad terminology that has gone, is fading, and is still in constant use in our world. I invite and encourage you to submit your own "favorite" bad pathology term in the comments section below, with a brief description of why it's a bad one. Since the comments are moderated it may take up to a day to see your posting appear on the blog and some minor editing may be done before acceptance.