Department of Pathology, University of Ottawa, Ottawa, Canada.
Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut, USA.
J Cutan Pathol. 2023 Mar;50(3):266-274. doi: 10.1111/cup.14369. Epub 2022 Dec 21.
Histopathologic features of interface dermatitis can occasionally be seen in mycosis fungoides (MF), particularly in early patch-stage disease.
We identified six patients with MF whose early biopsy specimens showed such prominent interface dermatitis that a benign diagnosis was favored. All subsequent specimens were reviewed for these patients, and the histopathologic evolution of disease was documented. Immunohistochemistry (IHC) for CD2, CD3, CD4, CD5, CD7, CD8, CD30, and CD123 was performed retrospectively. Educational archives were reviewed to assess the incidence of interface dermatitis in biopsies otherwise diagnostic of MF.
A spectrum of vacuolar and lichenoid patterns of interface change was observed in this series of six patients eventually diagnosed as having MF, and was seen as a recurring pattern in multiple specimens over time. In retrospect, findings described in early MF such as lining up of lymphocytes along the dermal-epidermal junction within the basal layer, papillary dermal fibrosis, and intraepidermal lymphocyte atypia could be appreciated to varying degrees in the confounding specimens. CD123 was negative in all cases, putatively excluding a connective tissue disease (CTD). None of the early biopsies showed loss of pan-T antigens CD2, CD5, and CD7. Forty-six of 164 cases (28%) of MF in an archival study set showed varying degrees of interface dermatitis in the setting of otherwise diagnostic changes of MF.
Early MF can show prominent interface change and mimic inflammatory dermatoses. Histopathologic clues suggestive of MF should be carefully assessed, and IHC for CD123 may be helpful in distinguishing MF from CTD. Repeat biopsies over time may be necessary to arrive at a definitive diagnosis, in conjunction with ancillary studies and strong clinicopathologic correlation.
界面性皮炎的组织病理学特征偶尔可见于蕈样肉芽肿（MF），尤其是在早期斑块期疾病中。
我们鉴定了 6 例 MF 患者，其早期活检标本显示出如此明显的界面性皮炎，有利于良性诊断。对所有这些患者的后续标本进行了回顾，并记录了疾病的组织病理学演变。回顾性进行了 CD2、CD3、CD4、CD5、CD7、CD8、CD30 和 CD123 的免疫组化（IHC）。评估了存档的教育材料，以确定在其他诊断为 MF 的活检中界面性皮炎的发生率。
在这一系列最终诊断为 MF 的 6 例患者中，观察到一系列空泡和苔藓样界面变化模式，并且随着时间的推移在多个标本中反复出现。回顾性地，在早期 MF 中描述的发现，如淋巴细胞沿基底层真皮表皮交界处排列、乳头真皮纤维化和表皮内淋巴细胞异型性，可以在混杂标本中不同程度地被观察到。所有病例的 CD123 均为阴性，推测排除结缔组织疾病（CTD）。在早期活检中均未观察到泛 T 抗原 CD2、CD5 和 CD7 的缺失。在存档研究中，MF 的 164 例病例中有 46 例（28%）在其他诊断为 MF 的改变的基础上显示出不同程度的界面性皮炎。
早期 MF 可表现为明显的界面改变并模拟炎症性皮肤病。应仔细评估提示 MF 的组织病理学线索，CD123 的 IHC 可能有助于将 MF 与 CTD 区分开来。随着时间的推移进行重复活检，结合辅助研究和强烈的临床病理相关性，可能有必要得出明确的诊断。
