A 33-year-old, 17-week pregnant woman (height 165 cm, weight 47.7 kg) visited the department of orthopedic surgery of a neighborhood hospital with a chief complaint of back pain. Medical history was unremarkable except ventricular extrasystoles on electrocardiogram since childhood. She was transferred to our hospital for further examination, with a suspicious diagnosis of a spinal tumor.
On admission, she was not able to walk unaided due to decreased muscle strength of bilateral lower limbs. Hypoesthesia below the seventh thoracic dermatome with increased bilateral patellar tendon and Achilles tendon reflex was observed. Magnetic resonance imaging (MRI) revealed a mass in the third thoracic vertebra, with T1-weighted signal intensity similar to and T2-weighted intensity slightly lower than the spinal cord (Fig. 1), suggesting bone giant cell tumor, granular cell sarcoma due to leukemia, malignant lymphoma, and osteosarcoma. Electrocardiography showed scattered ventricular extrasystoles as noted previously. Blood tests demonstrated mild anemia and increased inflammatory reaction. Catecholamines in the blood or urine were not measured. As the patient experienced rapid progression of leg paralysis, urgent thoracic posterior decompression with fusion and interval tumor resection was planned.
General anesthesia was induced with thiopental 200 mg, remifentanil 0.3 μg/kg/min, and rocuronium 40 mg followed by tracheal intubation and maintained with sevoflurane 1–1.5%, remifentanil 0.2–0.25 μg/kg/min, and bolus infusion of rocuronium 10 mg every 1 h. An abrupt increase of blood pressure to 223/162 mmHg with a heart rate of 103 bpm, followed by hypotension to 70/35 mmHg, was noted after tracheal intubation, but with small hemodynamic changes after changing the position to the prone. Fetal heart rate was intermittently monitored by an obstetrician using the ultrasound Doppler method to assess fetal well-being during the operation. Fetal heart rate was 150 bpm in the supine position and 140 bpm after the postural change to the prone position. When the bleeding exceeded 1000 mL, blood transfusion was started and fetal heart rate was confirmed to be > 130 bpm. Marked bleeding and hypertension (170/101 mmHg) were noted during tumor resection, immediately followed by hypotension (63/43 mmHg) during the suspension period of surgical resection despite massive blood transfusion (Fig. 2). Continuous infusion of noradrenaline was started. Resection of the tumor was abandoned, and only a biopsy was performed because of the persistent hypotension. Fetal heart rate was stable and maintained between 130 and 140 bpm. Intraoperative bleeding amounted to 4350 mL, and the total transfusion volume was 3930 mL (red blood cell concentrate, 16 units; fresh frozen plasma, 12 units; and platelet concentrate, 20 units). The operating time was 338 min. The patient was transferred to the intensive care unit (ICU) with continuous administration of noradrenaline, propofol, and tracheal intubation. Six hours after surgery, the patient was extubated in the ICU with the discontinuation of propofol.
On the following day, the circulatory dynamics improved, and noradrenaline was discontinued. The patient subsequently transferred to an inpatient orthopedic unit. Histopathological examination revealed that the tumor was a metastatic pheochromocytoma. Serum and urinary catecholamine levels were increased (serum adrenalin < 0.01 ng/mL, serum noradrenalin = 6.1 ng/mL, serum dopamine = 1.8 ng/mL, urinary adrenalin = 0.12 μg/day, urinary noradrenalin = 10 μg/day). Administration of doxazosin mesilate and carvedilol was started after the diagnosis. Fetal ultrasound on postoperative day 23 showed favorable fetal growth but indicated a tumorous lesion in the vesicouterine excavation. Based on the results of urgent pelvic MRI and needle biopsy, a definitive diagnosis of extra-adrenal pheochromocytoma in the urinary bladder with spinal metastasis was made. Since the continuation of pregnancy was life-threatening and posed a high risk to the patient, elective abortion was performed at 21 weeks and 4 days of pregnancy after discussion with the patient to prioritize the treatment of the underlying disease. Subsequently, the patient received chemotherapy and underwent surgeries for the residual tumor in the spine and the primary lesion, which led to remission.