Dao A H, Netsky M G
Hum Pathol. 1984 May;15(5):449-53. doi: 10.1016/s0046-8177(84)80079-9.
A case of a tail in a 2-week-old infant is reported, and findings from a review of 33 previously reported cases of true tails and pseudotails are summarized. The true, or persistent, vestigial tail of humans arises from the most distal remnant of the embryonic tail. It contains adipose and connective tissue, central bundles of striated muscle, blood vessels, and nerves and is covered by skin. Bone, cartilage, notochord, and spinal cord are lacking. The true tail arises by retention of structures found normally in fetal development. It may be as long as 13 cm, can move and contract, and occurs twice as often in males as in females. A true tail is easily removed surgically, without residual effects. It is rarely familial. Pseudotails are varied lesions having in common a lumbosacral protrusion and a superficial resemblance to persistent vestigial tails. The most frequent cause of a pseudotail in a series of ten cases obtained from the literature was an anomalous prolongation of the coccygeal vertebrae. Additional lesions included two lipomas, and one each of teratoma, chondromegaly , glioma, and a thin, elongated parasitic fetus.
报告了一例2周龄婴儿长尾巴的病例，并总结了对之前报道的33例真性尾巴和假性尾巴病例的回顾结果。人类的真性或持续性退化尾起源于胚胎尾的最远端残余部分。它包含脂肪和结缔组织、横纹肌中央束、血管和神经，并被皮肤覆盖。没有骨骼、软骨、脊索和脊髓。真性尾巴是由于保留了胎儿发育过程中正常存在的结构而产生的。它可能长达13厘米，可以移动和收缩，男性出现的频率是女性的两倍。真性尾巴很容易通过手术切除，且无残留影响。它很少具有家族性。假性尾巴是各种病变，共同特征是腰骶部突出，表面上类似于持续性退化尾。从文献中获取的一系列10例假性尾巴病例中，最常见的原因是尾椎异常延长。其他病变包括两个脂肪瘤，以及各一例畸胎瘤、软骨肥大、神经胶质瘤和一个细长的寄生胎儿。
