以前仅报道了一例由产生黑色素的甲状腺髓样癌(MTC)引起的黑色素瘤。在本研究中,报告了第二例此类病例,并与前一例进行了比较。患者是一名86岁的男性,表现为右前颈肿块。超声显示甲状腺右叶有一个49x48x40毫米的结节。血清降钙素(2,298pg/ml)和癌胚抗原(CEA;27.0ng/ml)的水平显着升高。抽吸细胞学检查显示怀疑是恶性甲状腺未分化癌,并进行了甲状腺全切除术,而没有进行颈部淋巴结清扫。粗略观察,结节包裹良好,软,实心和黑色。光学显微镜显示结节主要由大结节组成,偶尔巨大,多形性细胞,具有固体或肺泡生长模式。关于免疫组织化学,这些细胞对melan-A和S-100蛋白呈阳性,甲状腺转录因子1,降钙素,嗜铬粒蛋白A和CEA。在囊膜下区域,产生黑色素的MTC与多形性细胞紧密混合。在其他器官中没有检测到黑素瘤的原发部位。手术三年后,病人死于黑色素瘤转移到大脑。先前报道的病例在手术后长达11年没有发现复发或远处转移。与这种情况相比,本病例形态相似,但结局较差.因此,从MTC转化而来的黑色素瘤的预后似乎仍不确定.
Only one
case of melanoma arising from melanin-producing medullary thyroid carcinoma (MTC) has been reported previously. In the present study, a second such
case was reported and compared with the previous one. The patient was an 86-year-old male who presented with a right anterior neck mass. Ultrasound revealed a nodule measuring 49x48x40 mm in the right lobe of the thyroid. The levels of serum calcitonin (2,298 pg/ml) and carcinoembryonic antigen (CEA; 27.0 ng/ml) were markedly elevated. Aspiration cytology revealed suspected malignant anaplastic thyroid carcinoma and total thyroidectomy without neck nodal dissection was performed. On gross observation, the nodule was well encapsulated, soft, solid and black. Light microscopy indicated that the nodule was composed mainly of large, occasionally huge, pleomorphic cells with a solid or alveolar growth pattern. On immunohistochemistry, these cells were positive for melan-A and S-100 protein, and negative for thyroid transcription factor 1, calcitonin, chromogranin A and CEA. In the subcapsular area, melanin-producing MTC was intimately intermingled with the pleomorphic cells. No primary site of the melanoma was detectable in other organs. At three years after surgery, the patient died due to metastasis of the melanoma to the brain. The previously reported
case had no detectable recurrence or distant metastasis up to 11 years after surgery. In comparison with that
case, the present
case had a similar morphology but the outcome was poorer. Thus, the prognosis of melanoma that transforms from MTC appears to remain uncertain.