48 Clinical and Experimental Otorhinolaryngology Vol. 1, No. 1: 46-48, March 2008 Fig. 4. Histologic examination shows extracapsular hemorrhage and parathyroid adenoma (H&E stain ×50). The mass is mainly composed of fairly uniform, polygonal chief cells with small, centrally placed nuclei. clinical symptoms depend on the amount and the location of he- matoma, and various clinical presentations associated with the change in the PTH level may also be shown (7). Asymptomatic hyperparathyroidism does not require surgical treatment, however, careful follow-up is necessary for symptoms that require emergency treatment. Cervical hematoma from parathyroid adenoma requires surgical excision and evacuation of the hematoma if it results in airway compromise or hypercal- cemic crisis (3). Despite typical pathologic findings of parathyroid adenoma, the PTH was within normal limits (1, 2, 6, 8). There can be three possible hypotheses for this nonfunctioning parathyroid adenoma. First, there can be tissue necrosis secondary to cystic degeneration. Second, the path of PTH secretion may be transformed into the lumen of the cyst instead of the blood stream. Third, the pressure caused by the hematoma may interfere with the blood flow around the adenoma (7, 9, 10). However, we did not verify if there was necrotic change of the parathyroid ade- noma or an increased PTH level in the cyst in this case. In conclusion, spontaneous cervical hemorrhage of a parathy- roid adenoma may result in airway obstruction itself and may need the differential diagnosis of extracapsular hemorrhage of a cervical lesion (3, 11). Assessment of the calcium, phosphorus and intact PTH blood levels must be included in the diagnostic work up for spontaneous cervical hemorrhage from an unknown origin (2). REFERENCES 1. Sekine O, Hozumi Y, Takemoto N, Kiyozaki H, Yamada S, Konishi F. Parathyroid adenoma without hyperparathyroidism. Jpn J Clin Oncol. 2004 Mar;34(3):155-8. 2. Taniguchi I, Maeda T, Morimoto K, Miyasaka S, Suda T, Yamaga T. Spontaneous retropharyngeal hematoma of a parathyroid cyst: report of a case. Surg Today. 2003;33(5):354-7. 3. Chin KW, Sercarz JA, Wang MB, Andrews R. Spontaneous cervical hemorrhage with near-complete airway obstruction. Head Neck. 1998 Jul;20(4):350-3. 4. Kihara M, Yokomise H, Yamauchi A, Irie A, Matsusaka K, Miyauchi A. Spontaneous rupture of a parathyroid adenoma presenting as a assive cervical hemorrhage: report of a case. Surg Today. 2001 Mar;31(3): 222-4. 5. Deveze A, Sebag F, Pili S, Henry JF. Parathyroid adenoma disclosed by a massive cervical hematoma. Otolaryngol Head Neck Surg. 2006 Apr; 134(4):710-2. 6. Nakajima J, Takamoto S, Tanaka M, Takeuchi E, Murakawa T, Kitagawa H, et al. Parathyroid adenoma manifested by mediastinal hemorrhage: report of a case. Surg Today. 2002 Sep;32(9):809-11. 7. Tonerini M, Orsitto E, Fratini L, Tozzini A, Chelli A, Santi S, et al. Ce- rvical and mediastinal hematoma: presentation of an asymptomatic cer- vical parathyroid adenoma: case report and literature review. Emerg Ra- diol. 2004 Feb;10(4):213-5. 8. Angelos P, Thompson NW, Giordano TJ. Spontaneous vocal cord pare- sis and return to normocalcemia: an unusual presentation of parathyroid adenoma with concomitant abscess. Surgery. 1997 Jun;121(6):704-7. 9. Arkles LB. Preoperative localization of parathyroid adenomas: the pro- tagonist’s view. Intern Med J. 2002 Apr;32(4):179-82. 10. Hellier WP, McCombe A. Extracapsular haemorrhage from a parathy- roid adenoma presenting as a massive cervical haematoma. J Laryngol Otol. 1997 Jun;111(6):585-7. 11. Ku P, Scott P, Kew J, van Hasselt A. Spontaneous retropharyngeal ha- ematoma in a parathyroid adenoma. Aust N Z J Surg. 1998 Aug; 68(8): 619-21.