P Subroto, B Burt, Y Colson
mediastinal mass, parathyroid adenoma
P Subroto, B Burt, Y Colson. An "Acute" Mediastinal Mass. The Internet Journal of Thoracic and Cardiovascular Surgery. 2006 Volume 8 Number 2.
We describe a 73-year old female who presented with the acute onset of dysphagia and dyspnea. Upon workup, she was found to have a large mediastinal parathyroid adenoma that had spontaneously hemorrhaged. The evaluation and management of acute enlarging mediastinal masses is presented.
A 73-year-old woman experienced a three-day history of “sore throat”, increased malaise, and weakness. The patient rapidly developed stridor and an inability to handle oral secretions. Her past medical and surgical history includes hypertension, anemia, total abdominal hysterectomy and oophorectomy for a right ovarian cystic mass, and partial gastrectomy for peptic ulcer disease. On examination, the anterior chest wall and base of the neck were ecchymotic. Ultrasound and computed tomography (CT) of the neck demonstrated findings consistent with blood in the mediastinum, raising concern for a ruptured aortic arch dissection or arch aneurysm. She was subsequently intubated for airway protection. CT scan of the chest with intravenous contrast revealed an anterior mediastinal mass compressing the trachea. Its radiographic density was consistent with hematoma (Figure 1A and 1B).
Following intubation, bronchoscopy demonstrated tracheal compression without other lesions. Magnetic resonance imaging (MRI) of the chest showed a heterogeneous mass with low signal intensity on T1 and T2 weighted lesions (Figure 2A and 2B).
Gallium scan did not support the diagnosis of either infection or lymphoma. Biopsy was performed under CT guidance but was nondiagnostic. Cervical mediastinoscopy provided tissue consistent with hematoma. Laboratory analysis revealed an elevated calcium (ionized calcium 1.53 mmol/L (normal: 1.0-1.3 mmol/L)) and parathormone level (PTH = 334 pgm/ml (normal: 10-65 pgm/ml) that raised the suspicion that this mass could be a ruptured parathyroid adenoma. A sestamibi scan was performed and confirmed the diagnosis of parathyroid adenoma in the right lobe of the thyroid.
The patient was taken to the operating room and underwent parathyroid exploration with resection of a ruptured ectopic right upper parathyroid adenoma through a cervical collar incision. A tracheostomy was also performed for significant tracheomalacia. Her postoperative course was complicated by ventilatory failure and a left pleural effusion requiring tube thoracostomy. She was ultimately discharged to a rehabilitation facility where she successfully weaned from the ventilator.
This case is an interesting and unusual presentation of a ruptured parathyroid adenoma masquerading as a hemorrhagic mediastinal mass. Capps first reported this entity in 1934 and this proceeding represents the 5th report of mediastinal hemorrhage resulting from a ruptured parathyroid adenoma in the literature.1 Several important points in the workup and management of mediastinal masses are illustrated.
Airway control is paramount in patients with large mediastinal masses that impinge upon the airway. Complete airway collapse is possible in those with severely narrowed tracheal lumens from compressive masses, especially with the induction of anesthesia and paralysis respiratory musculature.2, 3 Fiberoptic awake intubation is usually necessary in these cases and awake tracheostomy may be required in some when total airway collapse is anticipated with anesthesia induction.2 Our patient was successfully intubated but did require a tracheostomy after neck exploration and removal of her parathyroid adenoma for tracheomalacia, which likely developed due chronic tracheal compression.
After ensuring that the airway is intact, chest imaging becomes the next priority in hemodynamically stable patients for diagnosis. Both chest CT and MRI are both useful in imaging mediastinal disease.3,4,5 Chest CT with intravenous contrast is rapid and readily available in most hospitals and is most helpful in the acute situation where it aids in eliminating pathology from the aorta or other major vessels as was done in our case. Chest CT also allows localization of the lesion into one of the three anatomical compartments of the mediastinum – anterior, visceral, and paravertebral, which allows a differential to be constructed.6 MRI allows more accurate detection of invasion of contiguous structures such as the chest wall and vascular structures. Tissue density characteristics on T1 and T2 imaging help narrow the differential by distinguishing between fat and fluid laden tissue.3, 5, 6 Specifically, MRI is useful for diagnosis of hematoma, with the characteristic on T2 imaging as seen in our patient. 3, 5, 6
Serum values for tissue specific tumor markers, alpha-fetoprotein (AFP) and human chorionic gonadotrophin (beta subunit) (β-HCG) may be helpful when the diagnosis is suspected or ellusive.5 However, definitive diagnosis is determined chiefly from tissue analysis. For retrieval of tissue, either percutaneous image-guided biopsy or surgical biopsy can be performed. Percutaneous CT-guided techniques are safe and often yield a diagnosis.7 In cases where percutaneous attempts are nondiagnostic, cervical or anterior mediastinoscopy, video-assisted thorascopic techniques, and even open biopsy or resection can be used for obtaining a tissue diagnosis.
In our case, adequate tissue for diagnosis could not obtained via either percutaneous or open surgical methods. Imaging studies and obtained tissue narrowed the diagnosis to mediastinal hematoma. This entity of spontaneous cervicomediastinal hemorrhage was first reported by Capps in 1934.1 Since that time approximately 40 cases of spontaneous cervicomediastinal or mediastinal hemorrhage have been reported in literature.3, 8,9,10 This syndrome is characterized by sudden substernal or scapular pain with neck swelling that can lead to airway or esophageal compromise or even superior vena caval compression. Five pathologic conditions are known to predispose to spontaneous bleeding in the mediastinum. They include 1. increased intrathoracic pressure 2. severe hypertension 3. impaired hemostasis from uremia 4. extramedullary hematopoietic tissue and 5. hemorrhage from a pre-existing mass. 3, 8,9,10 Of hemorrhagic mediastinal masses, only 15 cases have successfully reported identified the pathologic lesion with mediastinal parathyroid adenomas being the most common cause as first reported by Capps. Other identified causes are germ cell tumors which typically present in the 4th decade or life with elevated tumor markers, ectopic thyroid tissue, and thymic tumors and thymic cysts which present in the 5th decade of life. Other cases have been idiopathic. 3, 8,9,10
Our diagnosis was ultimately suggested by investigating the cause of the patient's elevated serum calcium. Elevated levels of PTH combined and sestamibi imaging prompted neck exploration and excision of the ruptured parathyroid adenoma.
Yolonda L. Colson, MD. Ph.D. Brigham and Women's Hospital Division of Thoracic Surgery 75 Francis Street Boston, MA 02115 Tel: (617) 732-6824 Fax: (617) 730-2853 E-mail: email@example.com