Florez Jose C, Burton Doug W, Arnell Paula M, Deftos Leonard J, Klibanski Anne
Department of Medicine, Endocrine Division, Massachusetts General Hospital, Boston, Massachusetts 02114, USA.
Endocr Pract. 2005 May-Jun;11(3):184-9. doi: 10.4158/EP.11.3.184.
To describe a case of metastatic rhabdomyosarcoma originating from the sphenoid sinus in a patient previously treated with conventional irradiation for a prolactinoma, presenting as hypercalcemia in the setting of a normal level of serum parathyroid hormone-related protein (PTHrP).
We report the case of a patient who underwent remote pituitary irradiation for a prolactinoma and then presented decades later with hypercalcemia of unknown cause. His clinical course, the initial biochemical and radiologic investigations, and the results of examination of pathology specimens are reviewed.
The patient was found to have a mass in the sphenoid sinus. The pathologic features were consistent with alveolar rhabdomyosarcoma. Although he had a normal serum PTHrP level, staining of his tumor with an antibody against PTHrP revealed local production of PTHrP at the tumor margins. His bone marrow biopsy specimen showed 100% involvement with rhabdomyosarcoma.
PTHrP staining of pathology specimens might explain hypercalcemia of undetermined cause in patients with a known malignant lesion, in whom elevated serum PTHrP levels cannot be demonstrated.
描述一例源于蝶窦的转移性横纹肌肉瘤病例，该患者曾因催乳素瘤接受传统放疗，在血清甲状旁腺激素相关蛋白（PTHrP）水平正常的情况下出现高钙血症。
我们报告一例患者，其因催乳素瘤接受垂体远距离放疗，数十年后出现不明原因的高钙血症。回顾其临床病程、初始生化和影像学检查以及病理标本检查结果。
该患者蝶窦内发现一个肿块。病理特征符合肺泡状横纹肌肉瘤。尽管他的血清PTHrP水平正常，但用抗PTHrP抗体对其肿瘤进行染色显示，肿瘤边缘局部产生PTHrP。他的骨髓活检标本显示100%被横纹肌肉瘤累及。
病理标本的PTHrP染色可能解释已知恶性病变患者中原因不明的高钙血症，这些患者血清PTHrP水平未升高。
