Case Report - (2021) Volume 10, Issue 3
Received: 02-Mar-2021
Published:
29-Mar-2021
, DOI: 10.37421/2165-7939.2021.10.474
Citation: Ma Jeasa G. Torrefranca, Rainick T. Navarro and Criscely L. Go. “A Rare Case of Metastatic Spinal Cord Compression Originating from Extragonadal Mediastinal Yolk Sac Tumor: A Case Report.” J Spine 10 (2021): 465.
Copyright: © 2021 Torrefranca MG, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Spinal metastases of nonseminomatous germ cell tumor (NSGCT) found in extragonadal location is a rare event and even more uncommon at the initial presentation. In this case report, we present a 20-year old male’s clinical presentation of spinal cord compression. He presented with paraplegia, neurologic bladder, and bowel dysfunction. Spinal Magnetic Resonance Imaging (MRI) demonstrated 9th thoracic vertebra metastasis, and cord compression with edema. A chest computed tomography scan with contrast further revealed mediastinal and right infrahilar mass. Its histopathological features were consistent with Yolk Sac Tumor (YST). Further investigation using bone scintigraphy revealed spinal metastasis. This case represents a rare clinical presentation and disease manifestation of a metastatic extragonadal YST originating from the mediastinum and causing spinal cord compression in an adult male. Although it is rare, spinal cord compression should raise awareness and prompt evaluation for metastatic lesions given the rate of NSGCT metastasis and its associated poor prognosis.
Extragonadal mediastinal yolk sac tumor • Spinal metastasis • Spinal cord compression
Yolk sac tumor is a subtype of germ cell tumor (GCT) that is highly malignant. They appear in both men and women and are usually associated with the testes and ovaries. When the testes and ovaries are not the primary sites, the tumors are called extragonadal YST [1,2]. Mediastinal GCT account for only 3% to 5% of all GCT [3]. Primary YST of the anterior mediastinum is rare and has a grave prognosis. These patients often present with advancedstage tumors that are bulky and unresectable [3]. YST is predominantly a disease of young adults and the average age at diagnosis is 18 years [1]. Moreover, metastatic bone disease is relatively uncommon and is found in the setting of retroperitoneal lymph node and/or visceral metastases [4]. Bone metastasis particularly in the spine secondary to an extragonadal GCT, such as this case, is an exceptionally rare presentation and to our knowledge, has never been reported locally. The prevalence of extragonadal YST presenting as spinal metastasis is still unknown.
This is a case of a 20-year old male admitted at our institution with a twoweek history of progressive bilateral lower extremity weakness, sensory deficit from thoracic level, urinary retention, and loss of bowel function.
The patient’s chest x-ray revealed soft tissue mass at the right hemithorax. An MRI demonstrated hyperintense signal in T2 involving the ninth vertebra, enhancing paraspinal mass with left neuroforaminal infiltration, exiting nerve root compression, and spinal cord edema in moderate degree (Figure 1).
Figure 1. Spine Magnetic Resonance Imaging on cross-sectional view showed left neuroforaminal infiltration, exiting nerve root compression, and spinal cord in moderate degree.
Further workup for anterior mediastinal mass using chest CT-scan demonstrated heterogeneously enhancing mass with fat component and coarse calcifications at the right infrahilar region (Figure 2). The tumor markers showed elevated Alpha-fetoprotein (AFP) at 58,727 ng/ml and lactate dehydrogenase at 314 U/L. Normal values were found for serum beta-HCG and CEA. Ultrasound of the whole abdomen, prostate, inguinal, and scrotal regions were unremarkable and negative for tumors.
Figure 2. Chest CT scan with contrast. Imaging showed 14.7 cm large hetetogenously enhancing mass with fat component and large coarse calcifications, right infrahilar region.
A CT-guided biopsy of the mediastinal mass revealed cells with scant cytoplasm, hyperchromatic vesicular nuclei surrounding a central cavity with hepatoid cells in solid sheets and are consistent with Schiller-Duvall bodies. Considering the negative whole abdominal, pelvic and scrotal ultrasound, a diagnosis of extragonadal or primary anterior mediastinal YST was reached.
A bone scan examination with Tc-99m HDP revealed radiotracer uptake on right eight anterior rib end and ninth thoracic vertebra were consistent with bone metastasis.
The patient underwent palliative radiation of the spine as out-patient, had regular follow-up and received two cycles of neoadjuvant chemotherapy. He developed sepsis secondary to pneumonia and eventually succumbed to his demise prior to a planned emergency decompression laminectomy of the spine.
Metastasis to the brain and spinal cord is a well-established cause of neurological dysfunction in patients with malignancies. It is estimated that 2-5% of patients with cancer have evidence of epidural metastasis [5,6]. Lung, prostate, and breast cancer each account for 15–20% of all cases in adults [7,8].
The anterior mediastinum is the most common site of extragonadal GCT. Benign mature teratoma or seminoma is the most common subtype while nonseminomatous germ cell tumors (NSGCT) such as yolk sac tumors are rare [9].
In a study with 64 cases of mediastinal NSGCT, the most common presentation was chest pain followed by shortness of breath, weight loss, chills and fever, and superior vena cava syndrome [10]. In current body of evidence, this is the first local case and the second reported case worldwide of a mediastinal YST presenting as spinal cord compression. The first case was described in a case report from University of California, Los Angeles (UCLA) Medical Center in an adult male where an anterior YST subsequently caused acute conus medullaris syndrome [11].
The most common pattern observed in a clinicopathologic study in YST was the reticular type, characterized by strands and cords of cells embedded in a myxoid or edematous stroma. The Schiller–Duvall bodies appearing as perivascular structure are considered pathognomonic in YST [12]. Alphafetoprotein (AFP) is an oncofetal glycoprotein that is expressed in YST and its variants. An elevated serum AFP level is closely associated with yolk sac tumors in more than 90% of patients [13,14].
Primary mediastinal NSGCT carries a poor prognosis with 40–50% 5-year relative survival rates after chemotherapy and surgery. The survival rate is 25% if there is evidence of metastatic disease [6]. Primary mediastinal NSGCT has the worst survival of all extragonadal GCT due to large tumor bulk at diagnosis, resistance to chemotherapy, and difficulty in removing all residual disease after chemotherapy [10]. A study confirms the aggressive nature of primary NSGCT of the mediastinum where 72% of patients for whom follow-up was available died of their tumors [10].
In conclusion, primary mediastinal yolk sac tumor is an aggressive tumor that infiltrates surrounding structures and metastasizes. Although spinal metastasis in a young adult is rare, it must still be considered and work-up must be done. In this study, we present the first local case of an extragonadal yolk sac tumor originating from the mediastinum of an adult male, metastasizing to the spine, and resulting in spinal cord compression. Although it is rare, symptoms of potential spinal cord compression should raise awareness and prompt evaluation for metastatic lesions given the rate of NSGCT metastasis and its associated poor prognosis.
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