Lymphoma or pseudolymphoma: A report of six cases and review of the literature.

To explore and compare the clinical presentations and pathologic features of cutaneous pseudolymphomas (CPL) with primary cutaneous lymphomas. Review literature in order to improve the treatment of CPL. Six cases of CPLs were collected. The clinical, pathologic, and immunohistochemical features were performed and analyzed in Peking Union Medical College Hospital in 2018. Of six patients, the distributions and clinical manifestations of skin lesions are varied. The pathologic features consisted of atypical prominent lymphocytes infiltration. Of them, two cases imitated mycosis fungoides, one case mimicked primary cutaneous aggressive pidermotropic CD8+ cytotoxic T-cell lymphoma, one case was diagnosed as Jessner-Kanof lymphocyte infiltration and two cases primary cutaneous CD4+ small/medium T-cell lymphoproliferative disorder. With respect to etiology, one was result from insects bite and the others were on account of drugs. All cases were treated with systemic or local glucocorticoid. The skin lesions and systemic symptoms showed notable improvement after treatment. Follow-up visits were 2 years, half a year, and months, respectively, without relapse. These unique types of CPL were similar to cutaneous lymphomas in clinical manifestation and pathology. They were all sensitive to the treatment of externally or orally using glucocorticoid. The prognosis is generally good but needs long-term follow-up.