Abstract: Objective To report a case of idiopathic immunoglobulin deficiency accompanied by peripheral T-cell lymphoma-unspecified.Methods Other neoplastic diseases were ruled out in this patient by medical history investigations,clinical and laboratory evaluations,including histopathological and immuno-histochemical examination.The effect of treatment was also evaluated.Results The patient was a 25-year-old male,presented with polymorphic skin lesions including papules,plaques and nodules on the left buttock,up lip,bilateral wings of nose,etc.He had suffered from recurrent serious infections.The serum level of IgG was significantly lower than normal(<0.069 g/L).Histopathologically,the dermis was infil-trated diffusely with various sized lymphocytes with atypical nuclei and mitotic figures.Immunohistochemical examinations revealed that the lesions were positive for CD7,CD2,CD4,and LAT,but negative for Ki-1, CD20,OCT2,CD56,CD68,CD79a.The patient was diagnosed with T-cell lymphoma.Resolution of the lesions was obtained after one month of treatment with intravenous gammaglobulin and oral CHOP(cyclophos-phamide+hydroxydaunomycin+oncovin+dexamethasone).Conclusions The diagnosis is established by pertinent laboratory findings.Clinical features are important clues,and may help to achieve an early diagnosis.

Key words: Agammaglobulinemia, Lymphoma, T-Cell, Rare diseases