Division of Dermatology, Department of Medicine of Sensory and Motor Organs, Faculty of Medicine, Tottori University, Yonago, Japan.
J Cutan Pathol. 2021 May;48(5):689-693. doi: 10.1111/cup.13960. Epub 2021 Jan 24.
In mycosis fungoides (MF), cutaneous granuloma formation is unusual. Furthermore, MF showing interstitial granuloma, a rare type, after combination therapy with interferon-gamma (IFN-γ) and narrowband UVB (nbUVB) has not been previously reported. A 77-year-old man was referred to our hospital with a 2-month history of erythroderma. Biopsied specimens revealed infiltration of atypical lymphocytes and eosinophils. A diagnosis of an erythrodermic variant of MF was made. He was treated with combination therapy of IFN-γ and nbUVB. After the therapy, papules newly appeared and a histopathological specimen revealed interstitial granuloma. There were several CXCR3-positive cells around the granuloma. We speculated that the combination therapy made T-helper 1 cells migrate to the cutaneous lesion and resulted in the granuloma formation. Furthermore, judging from the disappearance of elastic fibers around the interstitial granuloma, we considered that IFN-γ may induce the infiltration of histiocytes interstitially after damage of elastic fibers caused by nbUVB therapy, and both IFN-γ and nbUVB may thus play an important role in the histogenesis. Not only histopathology but also immunological observations are needed to elucidate the mechanisms underlying the development of different types of granuloma in MF.
在蕈样肉芽肿（MF）中，皮肤肉芽肿的形成并不常见。此外，干扰素-γ（IFN-γ）和窄谱中波紫外线（nbUVB）联合治疗后表现为间质性肉芽肿的罕见类型的 MF 尚未见报道。一位 77 岁男性因红皮病病史 2 个月就诊于我院。活检标本显示非典型淋巴细胞和嗜酸性粒细胞浸润。诊断为红皮病型 MF。他接受了 IFN-γ 和 nbUVB 的联合治疗。治疗后，新出现丘疹，组织病理学标本显示间质性肉芽肿。肉芽肿周围有几个 CXCR3 阳性细胞。我们推测联合治疗使辅助性 T 细胞迁移到皮肤病变部位，导致肉芽肿形成。此外，从间质性肉芽肿周围弹性纤维的消失判断，我们认为 IFN-γ 可能在 nbUVB 治疗引起弹性纤维损伤后，诱导组织细胞间质浸润，IFN-γ 和 nbUVB 可能因此在组织发生中发挥重要作用。不仅需要组织病理学观察，还需要免疫学观察来阐明 MF 中不同类型肉芽肿发展的机制。
