Unusual Histomorphologic and Immunohistochemical Features of Mycosis Fungoides in Patch and Plaque Stages Publisher



Ghanadan A¹ ; Kamyab K¹ ; Yadegar R¹ ; Maghsoodi M¹ Show Affiliations
Source: Iranian Journal of Dermatology Published:2023

Abstract

Background and Aim: Mycosis fungoides (MF) is the most common form of primary cutaneous lymphoma, resulting from the infiltration of malignant T cells into skin tissues. The disease has three distinct stages: patch, plaque, and tumor. In the patch and plaque stages, it can mimic the clinical features of benign dermatoses. However, two scoring systems facilitate diagnosis at these stages, which will be discussed in more detail in this study. Methods: In this cross-sectional study, all formalin-fixed and paraffin-embedded skin specimens highly susceptible to MF based on clinical examination at the patch and plaque stages were collected from April 2017 to August 2019. They were subjected to H&E and IHC staining tests and examined according to Guitart and Pimpinelli criteria. Results: Out of 78 samples, 76 had histological criteria for MF according to Guitart’s criteria, 54 were immunologically significant according to Pimpinelli’s criteria for MF, and 52 were classified as definitive MF according to both criteria. CD3 and CD4 markers were the most frequent markers, respectively. In contrast to previous studies, the CD7 marker was expressed at 10% or higher in 24 cases. In addition, 65 of 78 samples had a CD8 marker, and only 13 samples were CD8-.Conclusion: In the early stages of MF, a single scoring system does not have sufficient sensitivity for the diagnosis. The triad of the patient’s clinical presentation and histological and immunohistochemical features play a key role in achieving the correct diagnosis. © Iranian Journal of Dermatology.