Mycosis fungoides (MF) is a mature non-Hodgkin lymphoma of T cell origin, and a type of cutaneous T cell lymphoma (CTCL) . MF was first recognized in 1806 by a French dermatologist, Jean-Louis-Marc Alibert at the L’hôpital St. Louis in France [1]. In 1814, Alibert first named the disease pian fungoides due to its similarity with the treponemal disease yaws, or pian. In 1832, he went on to describe it as “a strange disorder of the skin with mushroom-like tumors” [2]. Alibert’s patient at the time suffered from desquamating rashes, which progressed into multiple lesions on his face and trunk region. Although Alibert was not aware of MF’s pathological background, he was aware that the lymphoma was indeed not a fungus [1].

In 1876, MF became known as Alibert-Bazin disease , named after Alibert and Pierre-Antoine-Ernest Bazin who contributed toward an early comprehensive characterization of the disease [1]. Their description of MF included three stages: non-specific erythematous (premycotic), plaque (lichenoid), and tumor (fungoid). Bazin described a progression from premycotic phase to plaque lesions and finally to tumor s. Following these discoveries, Vidal and Barocq described MF d’emblée for patients with tumors not preceded by plaques or patches (cases of which are now thought to represent other forms of CTCL). Besnier and Haopeau later characterized an erythrodermic form of MF [3, 4]. Taken together, these descriptions formed the early characterizations of MF, which were later followed by descriptions of Sézary’s syndrome (SS), the leukemic variant of CTCL.

Today we know that CTCL comprise a diverse group of non-Hodgkin lymphomas (NHL) caused by malignant skin-trafficking T cells. MF is the most common type of CTCL. Primary cutaneous lymphomas are classified by the European Organization for Research and Treatment of Cancer (EORTC) and the World Health Organization (WHO) (Table 1.1).