甲状腺乳头状髓样癌的组织学特征是既无滤泡也无乳头。本文报告一例罕见的甲状腺乳头状髓样癌，据查这种报告国内未见报道。患者男性，４９ 岁。因左颈部肿物数月，近期逐渐增大入院。经查体和实验室检查临床诊断为甲状腺癌，行甲状腺肿块切除术。病理检查　巨检：送检肿物呈圆型，直径约２ｃｍ ，无完整包膜，质地较实。切面灰白色，与周围分界较清。镜检：肿瘤有部分呈乳头状结构，乳头中心为纤维血管束，细长而不规则（ 图１） 。乳头表面被以单层或复层、柱状或多边形细胞，细胞异形，排列紊乱，胞体肥大，胞浆丰富，淡粉染。胞核大小不一，圆形、椭圆形或不规则，偶见双核，染色质颗粒状，可见小核仁及核分裂像。小部分包膜下肿瘤组织，瘤细胞小，大小较一致，浆少，核深染，类似小细胞癌。间质血管丰富，有大片均匀红染的团块物沉积（ 图２） ，刚果红染色阳性，证实为淀粉样物质沉着。乳头间质中未见砂粒体及钙盐沉着。免疫组化染色：肿瘤组织周围的正常甲状腺滤泡显示甲状腺球蛋白阳性，而肿瘤细胞则显示阴性，肿瘤细胞降钙素、 Ｎ Ｓ Ｅ均为阳性。病理诊断：甲状腺乳头状髓样癌讨论：甲状腺乳头状髓样癌实属罕见〔１ 〕，应与甲状腺乳 头状癌鉴别。二者均有复杂分枝的癌性乳头，但近年乳头状癌 The histological features of papillary medullary carcinoma of the thyroid gland are neither follicular nor nipple. This paper reports a rare case of thyroid papillary medullary carcinoma, which has not been reported in China. The patient is male, 49 years old. Due to the left neck mass for several months, she has recently been admitted to hospital gradually. After thyroid cancer was diagnosed by physical examination and laboratory tests, thyroidectomy was performed. Pathological examination Giant examination: The delivery of the tumor was round, about 2cm in diameter, no complete envelope, texture is more real. The cut surface is grey and white, with clearer boundaries. Microscopic examination: The tumor was partially papillary, and the center of the nipple was a bundle of fibrovascular vessels that was slender and irregular (Figure 1). The surface of the nipple is single or multi-layered, columnar or polygonal cells, abnormal cell shape, disorderly arrangement, cell body hypertrophy, abundant cytoplasm and pale pink staining. Nucleus sizes vary, round, oval or irregular, occasionally binuclear, chromatin granular, visible small nucleoli and mitotic figures. A small part of the tumor under the capsule, the tumor cells are small, the size is more consistent, less pulp, deep nuclear staining, similar to small cell carcinoma. The interstitial blood vessels are abundant and there are large masses of uniform red-stained agglomerates (Figure 2). Congo red staining is positive, confirming the amyloid deposition. There was no sand and calcium deposits in the nipples. Immunohistochemical staining: Normal thyroid follicles around the tumor tissue showed positive thyroglobulin, whereas tumor cells showed negative, and tumor cells were positive for calcitonin and NSE. Pathological diagnosis: Papillary medullary carcinoma of the thyroid Discussion: Papillary medullary carcinoma of the thyroid is rare (1). It should be differentiated from thyroid papillary carcinoma. Both have complex branches of cancerous papilla, but in recent years papillary carcinoma