Histopathologic staging at initial diagnosis of mycosis fungoides and the Sézary syndrome. Definition of three distinctive prognostic groups.

Study Objective: To determine the optimal staging evaluation at the time of initial diagnosis of mycosis fungoides or the Sézary syndrome.

Design: Retrospective review of a uniformly staged inception cohort.

Setting: Single-institution tertiary care center.

Patients: 152 consecutive patients who had mycosis fungoides with or without the Sézary syndrome within 6 months of the initial definitive diagnosis.

Intervention: A detailed staging evaluation including physical examination, routine laboratory studies, chest roentgenogram, lymphangiogram, peripheral blood smear, lymph node biopsy, bone marrow aspirate or biopsy, and liver biopsy in selected patients.

Measurements And Main Results: Univariate adverse prognostic features at initial diagnosis in patients with mycosis fungoides included (P less than 0.01) one or more cutaneous tumors or generalized erythroderma, adenopathy, blood smear involvement with Sézary cells, lymph node effacement, eosinophilia, and visceral involvement. Important, independent prognostic factors in a multivariate analysis are the presence of visceral disease and type of skin involvement.

Conclusions: A staging system based on histopathologic evaluation of skin, lymph nodes, blood, and visceral sites provides more comprehensive prognostic information than clinical evaluation of skin disease and adenopathy. Patients may be divided at initial presentation into three prognostic groups: good-risk patients, who have plaque-only skin disease without lymph node, blood, or visceral involvement (median survival, greater than 12 years); intermediate-risk patients, who have cutaneous tumors, erythroderma, or plaque disease with node or blood involvement but no visceral disease or node effacement (median survival, 5 years); and poor-risk patients, who have visceral involvement or node effacement (median survival, 2.5 years).