Primary yolk sac tumor of pterygopalatine fossa with loss of vision: A case report

INTRODUCTION: Primary yolk sac tumor (YST) is an infrequently-diagnosed malignant extragonadal germ cell tumors. It is likely to recur locally and may present with widespread metastases once diagnosed. Primary YST of the head is uncommon but can cause severe complications, such as loss of vision once the tumor mass invades the optic nerve. PATIENT CONCERNS: A 20-month-old boy presented to the general clinic of the local children's hospital with a complaint of swelling of left face for 1 year and proptosis of the left eye for over 2 weeks as stated by his parents. Initially, he did have some vision, as he could walk by himself, but a special ophthalmologic examination was not performed. DIAGNOSES: Cranial computed tomography and magnetic resonance imaging revealed a large tumor accompanied by peripheral bone destruction in the left pterygopalatine fossa that extended to sphenoid, ethmoid, left maxillary sinuses, left nasoethmoid, and left orbit. The optic nerve was invaded on both sides. Chest and abdominal imaging were normal. A primary diagnosis of Langerhans cell hyperplasia was made. However, blood tests on the second day of hospitalization revealed significantly elevated serum alpha-fetoprotein levels. On the third day, the boy lost his eyesight, with loss of pupillary and no light sensation during flashlight stimulation on both sides. INTERVENTIONS: Nasal endoscopy was performed on the fourth day, the vast majority of soft tissue mass was resected for biopsy. Histopathological examination revealed features of endodermal sinus tumor. A final diagnosis of primary YST of pterygopalatine fossa was made. Because the mass could not be resected completely, he received combined chemotherapy with bleomycin, etoposide, and carboplatin for 6 cycles over six months. OUTCOMES: The patient recovered with significant tumor shrinkage and without secondary metastasis after 18 months but left permanently blind. CONCLUSION: The worst complication of loss of vision after Primary YST of pterygopalatine fossa alerts us that close physical examination during the initial investigation should be performed, which is especially important in young children who cannot express complaints well. Early detection and treatment with surgical resection and chemotherapy may contribute to satisfactory outcomes and avoidance of visual impairment.