CONSIDER A 50-year-old man. For perhaps 10 or 15 years he has had slightly scaling, pink patches on his trunk. He brought these to the attention of his internist, who told him that they most likely represented eczema and prescribed a cream that contained both steroids and an antifungal agent. The patches improved slightly at times, but never went away entirely. One day, he visits a dermatologist because he has an unusual-appearing mole on his back. The dermatologist inquires about the patches and, after hearing his story, is concerned enough to perform a biopsy. Being of an inquisitive mind (with full disclosure and approval from every ethics committee imaginable), she performs several dozen biopsies on him. She sends some of the specimens to a dermatopathology laboratory, some to the general pathologists at the local hospital, some to a hematopathologist at the university hospital she is associated with, and some to a laboratory for processing so she can look at them herself (in a year, after altering the slide label so that she will not know what patient the specimen came from). Will she get the same answer (mycosis fungoides, not mycosis fungoides but "X," or I don't know) from all of the observers? What if she takes several dozen biopsy specimens from this unfortunate but wonderfully cooperative patient and sends them under an assumed name to the same pathologists? Will the original results be duplicated?
Ming M, LeBoit PE. Can Dermatopathologists Reliably Make the Diagnosis of Mycosis Fungoides?If Not, Who Can?. Arch Dermatol. 2000;136(4):543-546. doi:10.1001/archderm.136.4.543