We report a case of granulomatous mycosis fungoides that progressed into fatal gastrointestinal involvement 4 years after the onset of skin lesions, despite improvement of the skin lesions in response to a combination of PUVA and systemic interferon-gamma therapy. Histological examination showed Pautrier's microabscesses with granuloma annulare-like features and sarcoidal granuloma formation in the plaque stage, proliferation of blast-transformed atypical lymphocytes with persistent granuloma formation in the tumour stage, and metastatic lesions. A literature review of granulomatous mycosis fungoides revealed that 11 of the 24 reported cases died of the disease, and like our case, seven died within 5 years. We suggest that mycosis fungoides with granulomatous reactions does not indicate a favourable prognosis.