Nakamura A, Inoue Y, Ishihara T, Matsunaga W, Ono T
Department of Dermatology, Kumamoto University School of Medicine, Japan.
J Dermatol. 1995 May;22(5):365-9. doi: 10.1111/j.1346-8138.1995.tb03406.x.
Four Japanese male students, aged 14, 16, 18 and 19, were found to have a nodule in their coccygeal regions. The typical lesion was a rugby-ball-shaped, normal-colored or slightly erythematous nodule measuring 5 to 6 cm in its long axis. Histopathologically, it showed hyperplasia of collagen fibers and slight acanthosis. All four students rode to school by bicycle over long distances and long periods; three of them developed the nodule after they started bicycle riding to school. We found that the nodule shape corresponded to the saddle of the bicycle. X-ray abnormalities included bending or anterior dislocation of the coccyx in all cases and spina bifida in two cases. These nodules may have developed as a result of irritation of this region by the saddle of the bicycle.
四名日本男学生，年龄分别为14岁、16岁、18岁和19岁，被发现尾骨区域有一个结节。典型病变是一个橄榄球形状、颜色正常或略呈红斑的结节，长轴为5至6厘米。组织病理学显示，它表现为胶原纤维增生和轻度棘皮症。所有四名学生都长期远距离骑自行车上学；其中三人在开始骑自行车上学后出现了结节。我们发现结节的形状与自行车座吻合。X线异常包括所有病例均有尾骨弯曲或前脱位，两例有脊柱裂。这些结节可能是由于自行车座对该区域的刺激而形成的。
