18F-fluorodeoxyglucose-positron emission tomography is more sensitive than computed tomography in initial staging of patients with an anaplastic T-cell lymphoma first presenting in the skin.

Abstract

The role of 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET) in the evaluation of anaplastic large-cell lymphoma (ALCL) first presenting in the skin is not well established, while computed tomography (CT) is used as a standard procedure. The aim of this study was to evaluate the use of FDG-PET versus CT at initial staging of ALCL first presenting in the skin. Eleven cases of ALCL first presenting in the skin who underwent both FDG-PET and CT were retrospectively analysed. There were six males and five females, with a mean age of 59.7 years. Results of FDG-PET were compared with those of CT. Biopsy results of lesions served as a reference for the accuracy of PET and CT in the evaluation of local and metastatic lesions. In seven cases (64%), imaging revealed extracutaneous ALCL. FDG-PET results were concordant with CT results in five cases (45%); in four of these cases, FDG-PET was negative, consistent with CT, and one case had cutaneous and extracutaneous lesions detectable on both CT and FDG-PET. FDG-PET and CT were discordant in six cases (55%). Among these six cases, FDG-PET revealed extracutaneous lesions undetected on CT which consequently influenced the therapeutic decision in five cases (45%). The sensitivity of CT and FDG-PET was 18% and 64%, respectively.