First complete account of pernicious anemia. "In 1877, William Gardner and Osler described a patient who was almost certainly the first with the clinical, hematologic, and pathologic features to leave no doubt it was Addisonian pernicious anemia. 12 , 13 The case was that of a 52-year-old Englishman who complained of weakness and dyspnea on exertion, numbness of the fingers and the hands (difficulty buttoning his clothes), and a throbbing sensation in his temples. He died of progressive symptoms 3 months later. In the peripheral blood, Osler described macro-ovalocytes that measured up to 14 × 9 µ and large nucleated red cells with abnormal chromatin. At autopsy, pallor of the skin and organs was described, as well as a peculiar lemon tint to the skin and a thin gastric membrane. The bone marrow disclosed intense hyperplasia and was filled with large nucleated red cells having homogeneous stroma and finely granulated nuclei. This was the first clear description of the megaloblast so named by Paul Ehrlich 3 years later. Osler rejected William Pepper’s idea that PA was a form of pseudo-leukemia but hypothesized instead that it was a reversion of the bone marrow to an embryonic state, though why he did not know. Osler remarked it was “a disease … concerning the pathology of which we still have a good deal to learn, and concerning the successful treatment of which we as yet know nothing” (Marvin J. Stone, "Diabetes mellitus and pernicious anemia: Interrelated therapeutic triumphs discovered shortly after William Osler’s death," Proc. (Baylor Univ. Med. Cent) 33 (2020) 689-692).