Parathyroid carcinoma represents a rare malignancy of the parathyroid glands, most often arising sporadically but sometimes associated with genetic syndromes, eg, multiple endocrine neoplasia (MEN) syndrome types I and IIa and hyperparathyroidism-jaw tumor (HPT-JT) syndrome. This carcinoma accounts for fewer than 1% of primary hyperparathyroidism cases and occurs equally in men and women, most commonly during midadulthood. Loss of tumor suppressor function, frequently through mutations, drives disease progression by promoting excessive hormone secretion and aggressive local invasion. Histopathologic confirmation requires identification of capsular or vascular invasion, while parafibromin loss assists in distinguishing carcinoma from benign lesions. Clinically, suspicion increases with the presence of a firm neck mass accompanied by severe hypercalcemia, making comprehensive history-taking and physical examination essential for early recognition. Biochemical testing and imaging modalities, including ultrasound, sestamibi scanning, and 4-dimensional computed tomography (4D-CT), guide lesion localization, and advanced positron emission tomography/computed tomography (PET/CT) techniques contribute to the detection of metastatic disease. En bloc surgical resection remains the primary treatment and offers the best chance for long-term survival, though recurrence frequently complicates outcomes and often necessitates systemic therapy or targeted medical management. Differential considerations include benign parathyroid adenomas, thyroid nodules, and metastatic tumors, yet no standardized staging system exists. Prognosis depends largely on early complete resection, while recurrence and hypercalcemia drive long-term morbidity and mortality. Complications stem both from the endocrine effects of the tumor and from risks associated with surgical and medical interventions. Effective patient education, combined with interprofessional coordination, ensures timely diagnosis, appropriate treatment, and structured long-term surveillance in this challenging disease.
甲状旁腺癌是一种起源于甲状旁腺的罕见恶性肿瘤。甲状旁腺的正常重量和大小各不相同。平均重量约为60毫克。每个腺体的平均尺寸为长5毫米、宽3毫米、厚1毫米。正常甲状旁腺的颜色为黄褐色。甲状旁腺一般有4个，2个上甲状旁腺和2个下甲状旁腺；它们位于甲状腺的后外侧表面。腺体的位置可能因发育过程中的胚胎下降情况而有所不同。下甲状旁腺和胸腺均起源于第三鳃囊，而滤泡旁C细胞和上甲状旁腺起源于第四鳃囊。上甲状旁腺常位于环甲关节附近，正好在喉返神经与甲状腺下动脉交叉点的上方。上甲状旁腺与甲状腺上极的后包膜紧密相连。下甲状旁腺的位置变化较大，超过50%位于甲状腺下极，但它们也可沿甲状腺胸腺韧带位于前纵隔。极少数情况下会出现额外的甲状旁腺。甲状旁腺与喉返神经的关系是一种重要的解剖关系。上甲状旁腺在喉返神经的深面，而下甲状旁腺在其浅面。在大多数情况下，每个甲状旁腺的动脉血供来自甲状腺下动脉，它是甲状颈干的一个分支。在20%的病例中，其血供可能来自甲状腺上动脉，它是颈外动脉的一个分支。甲状旁腺、喉、咽、食管和气管之间通常有丰富的吻合支。静脉引流与动脉血管平行，汇入颈内静脉。甲状旁腺的淋巴管汇入颈深淋巴结和气管前淋巴结，与甲状腺的淋巴引流相似。甲状旁腺的主要功能细胞是主细胞，其含有许多细胞质分泌颗粒。这些细胞负责产生甲状旁腺激素。构成甲状旁腺实质的第二种细胞类型是嗜酸性细胞。它们的功能尚不清楚，但往往富含线粒体。嗜酸性细胞浓度高的甲状旁腺可能更容易发生功能亢进。与所有恶性肿瘤一样，甲状旁腺癌是甲状旁腺细胞不受控制或无规律生长的结果，大多数甲状旁腺癌具有功能——即它们分泌甲状旁腺激素（PTH）。甲状旁腺癌可发生于任何一个甲状旁腺，似乎对上甲状旁腺或下甲状旁腺（或额外的甲状旁腺）均无偏好，不过由于该疾病罕见，无法得出任何确切结论。其标志性特征是血清PTH水平非常高，常常达到数千，这在良性甲状旁腺功能亢进中很少见。
