Division of Pathology, Kobe University Graduate School of Medicine, Kobe, Japan.
Diagn Pathol. 2010 Jan 14;5:5. doi: 10.1186/1746-1596-5-5.
Melanotic variant of oncocytic metaplasia of the nasopharynx is an extremely rare condition.
A 73-year-old Japanese man presented with nasal congestion and chill. Nasoscopic examination revealed multiple black nodules around the bilateral torus tubarius. The nodules were biopsied to determine the histology. The clinical differential diagnosis was malignant melanoma or hemangioma. Microscopically, there were oncocytic plump cells with abundant brown pigmented granules showing glandular pattern. No significant atypia was found. The pigment was positive for Fontana-Masson staining, and negative for Berlin blue staining, showing that it was melanin pigment. Immunohistochemically, S100-positive HMB45-negative dendritic cells were also found.
Such a pigmented variant of benign oncocytic lesion is very rare, and only 15 cases have been reported in the English literature. As a benign mimicker of malignant melanoma, melanocytic oncocytic metaplasia should be always taken into consideration in the clinical setting.
鼻咽部嗜酸细胞型化生黑色素变异是一种极为罕见的情况。
一名 73 岁的日本男性因鼻塞和寒战就诊。鼻内窥镜检查显示双侧鼻甲周围有多个黑色小结节。对这些结节进行活检以确定组织学。临床鉴别诊断为恶性黑色素瘤或血管瘤。显微镜下，可见有丰富棕色色素颗粒的嗜酸细胞性饱满细胞呈腺样模式。未发现明显异型性。色素经 Fontana-Masson 染色阳性，柏林蓝染色阴性，表明为黑色素色素。免疫组化检查还发现 S100 阳性、HMB45 阴性的树突状细胞。
这种色素性良性嗜酸细胞病变变异非常罕见，英文文献中仅报告了 15 例。作为恶性黑色素瘤的良性模拟物，在临床环境中应始终考虑到黑色素细胞嗜酸细胞化生。
