In 1863, Besnier became
médecin des hôpitaux. He succeeded
Pierre-Antoine-Ernest Bazin as director at the Hôpital Saint Louis. He built
histopathology and
parasitology laboratories at the hospital, and is credited with originating the term
biopsy for tissue samples. In 1889 he proved an early description of skin lesions associated with
sarcoidosis, introducing the name "
lupus pernio". With
Pierre Adolphe Adrien Doyon (1827–1907), he founded the medical journal
Annales de dermatologie et de syphiligraphie. Besnier attempted to balance the differences between the French and Viennese approaches to dermatological medicine, and in 1881 with Doyon, translated
Moritz Kaposi's famous book on skin diseases (
Pathologie und Therapie der Hautkrankheiten in Vorlesungen für praktische Ärzte und Studirende) from German into French (
Leçons sur les maladies de la peau). With
Louis-Anne-Jean Brocq and
Lucien Jacquet, he published a four volume encyclopedia of dermatology, titled "
La pratique dermatologique" (1900–04). ==Death and legacy==