Diabetes, Endocrine and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.
J Clin Endocrinol Metab. 2012 Jun;97(6):1834-41. doi: 10.1210/jc.2011-3030. Epub 2012 Apr 16.
Due to frequent multiplicity of tumors in multiple endocrine neoplasia type 1, it may be difficult to decide when to stop a parathyroid exploration. A fall of intraoperative serum PTH by a certain percentage during parathyroid surgery is often used as one criterion for ending the operation.
We report two patients with primary hyperparathyroidism due to multiple endocrine neoplasia type 1 who had their first parathyroidectomy at the National Institutes of Health. In both cases, two and a half glands were removed, an extensive search was done for an occult parathyroid tumor, and intraoperative PTH decreased markedly to the lower limits of normal, suggesting a successful operation. Despite this, both patients became hypercalcemic within 3 d after the operation and showed persistent primary hyperparathyroidism. Detailed findings suggest the following course: chronic hypercalcemia had caused near total suppression of PTH secretion by an undiscovered parathyroid tumor (sleeping parathyroid tumor). When the hypercalcemia decreased after surgery due to the removal of the dominant parathyroid tumor(s), the abnormal yet previously suppressed tumor rapidly began to oversecrete PTH and thus caused postoperative hypercalcemia.
Even a fall of the intraoperative PTH to the lower limits of the normal range cannot guarantee that removal of all parathyroid tumors has been complete in cases with multiple tumors. These findings likely reflect strikingly differing PTH secretory functions among distinct tumors in the same patient, with hypercalcemia at least from a dominant tumor suppressing PTH secretion by one or more other parathyroid tumors.
由于多发性内分泌肿瘤 1 型的肿瘤常有多发性，因此可能难以确定何时停止甲状旁腺探查。甲状旁腺手术中，术中血清甲状旁腺激素（PTH）下降一定百分比通常用作手术结束的标准之一。
我们报告了 2 例多发性内分泌肿瘤 1 型相关原发性甲状旁腺功能亢进症患者，他们在国立卫生研究院（National Institutes of Health）接受了首次甲状旁腺切除术。在这两种情况下，均切除了 2.5 个腺体，进行了广泛的隐匿性甲状旁腺肿瘤搜索，术中 PTH 明显下降至正常下限，提示手术成功。尽管如此，这 2 例患者术后 3 天内均出现高钙血症，并持续存在原发性甲状旁腺功能亢进症。详细的检查结果提示如下：慢性高钙血症导致了尚未发现的甲状旁腺肿瘤（休眠性甲状旁腺肿瘤）对 PTH 分泌的几乎完全抑制。由于手术切除了优势甲状旁腺肿瘤，术后高钙血症因占主导地位的甲状旁腺肿瘤的消除而降低，而异常但先前受抑制的肿瘤则迅速开始过度分泌 PTH，从而导致术后高钙血症。
即使术中 PTH 降至正常范围下限也不能保证在多发性肿瘤的情况下已完全切除所有甲状旁腺肿瘤。这些发现可能反映了同一患者中不同肿瘤之间明显不同的 PTH 分泌功能，高钙血症至少来自于一个优势肿瘤，通过一个或多个其他甲状旁腺肿瘤抑制 PTH 分泌。
