Nodular Prurigo Associated with Mycosis Fungoides - Case Report.

Mycosis fungoides (MF) is the most common type of cutaneous lymphoma and accounts for approximately 50% of all lymphomas arising primarily in the skin. The three types of MF lesions are patches, plaques, and tumors, according to which the disease is traditionally divided into three clinical stages. The clinical course can be protracted and take years or decades. In the final stage, MF evolves to a systemic form of the disease. Nodular prurigo (NP) is still a condition of unknown etiology characterized by papulonodular eruption and intense pruritus. Multiple diseases, including dermatological, systemic, and psychiatric diseases, have been assumed to cause NP. Pruritic skin lesions have been known to precede clinically evident B and T cell lymphomas for years. In the literature, pruritus and NP have been reported in patients affected by systemic Hodgkin and non-Hodgkin lymphomas. Only two cases of cutaneous lymphoma as underlying disease in patients with PN have been reported in the literature. We report a rare case of a patient with concomitant non-Hodgkin skin lymphoma - MF and NP. Our female patient with a 10-year history of MF stage IIb during the last three years had been presenting for regular check-up with itchy, newly formed, rarely disseminated nodules 5-8 mm in diameter on the forearms and lower legs. Sharply limited erythematosquamous, slightly infiltrated foci (as part of MF as the underlying disease) were visible on the trunk and extremities. Extracutaneous involvement of MF was excluded. We performed a biopsy on a nodule from the lower leg to rule out tumor stage MF; the biopsy confirmed NP. We conclude that prurigo nodules should not be confused with tumor stage MF. NP is a therapeutic challenge for any dermatologist. Any underlying diseases should be treated first.