Mycosis fungoides presented as a tumor of the arytenoid cartilage and epiglottis of the larynx of an 80-year-old female. The tumor was initially interpreted as an undifferentiated small cell malignant neoplasm and treated with radiation. Two years later the patient developed widespread cutaneous involvement with mycosis fungoides, including mycosis fungoides bullosum. The mycosis fungoides progressed to death over the next two years. At autopsy widespread visceral involvement was present. The larynx was extensively infiltrated with mycosis fungoides, and the histology was similar to the original laryngeal biopsy. Although mycosis fungoides is generally thought of as a cutaneous disease, it may rarely present in a squamous epithelium-lined organ other than the skin.