Introduction: The initial staging and follow-up of cutaneous lymphomas is far from being standardized. In this retrospective study, we describe the results of systematic laboratory investigations dedicated to a better definition of the TNM stage for the detection of associated malignancies.
Patients and methods: This was a retrospective, descriptive, single centre study, including all cases of cutaneous lymphomas seen in the department of dermatology, university hospital of Reims, between 1987 and 2001. Data systematically recorded for each patient included clinical, biological, histological and molecular (cutaneous or circulating T or B clone) findings, imaging (thoracic and abdominal computed tomography scan; or chest X-ray and abdominal ultrasound tomography) and bone marrow histology (for B-cell cutaneous lymphomas only).
Results: In cutaneous T-cell lymphomas (n=63 including 47 mycosis fongoides), imaging revealed deep lymph nodes in 4 cases, a carcinoma of the kidney in one case, and a benign tumour in 6 cases. A T-cell clone was detected in the skin in 19/33 cases and in peripheral blood in 17/31 cases. In cutaneous B-cell lymphomas (n=23), imaging showed splenomegaly in 2 cases, a B-cell clone was detected in 3/12 cases in the skin, and bone marrow histology was normal in 21/22 cases. Among patients with cutaneous T-cell lymphomas, 14/63 (22 p. 100) had an associated malignancy. In 8/14 cases, the diagnosis of the associated malignancy was made prior to that of the cutaneous T-cell lymphoma. In 4 cases, the interval between the previous malignancy and the diagnosis of lymphoma was <or=2 Years, and in 2 other cases the malignancy was discovered on the occasion of the staging of the T-cell cutaneous lymphoma.
Conclusion: Laboratory investigations in cutaneous lymphomas are necessary to research deep lymph nodes, especially in case of high stage T-cell lymphomas. In exceptional cases they can reveal an associated malignancy, which is usually detected by clinical examination. In cutaneous B-cell lymphoma, bone marrow histology or cytology is generally normal hence may not be justified in low grade or localized cutaneous B-cell lymphomas.