Extragonadal Cervico-Parotid Yolk Sac Tumor with a Sarcoma-like Presentation in a Child: A Case Report with Fulminant Course and Literature Review
Dr Zineb Berdi*, Dr Zakaria EL Hafi, Pr Razika Bencheikh, Pr Mohamed Anass Benbouzid and Pr Leila Essakalli
Abstract
Background: Extragonadal malignant germ cell tumors of the head and neck are exceptional in children. Among them, pure yolk sac tumor arising in the parotid region and deep neck spaces is extremely rare, and its clinical and radiological presentation may mimic a soft-tissue sarcoma, exposing the patient to diagnostic delay.
Case Presentation: We report the case of a previously healthy 5-year-old girl admitted for a rapidly enlarging right lateral cervical swelling evolving over two months. Examination found a firm, polylobulated mass with intraoral extension narrowing the oropharyngeal lumen. Contrast-enhanced CT and MRI showed a large heterogeneous mass centered on the right parotid region, extensively infiltrating the nasopharynx, tongue base, floor of mouth, parapharyngeal, masticator, submandibular and visceral neck spaces, eroding the thyroid cartilage and mandibular ramus, and associated with ipsilateral cervical lymphadenopathy; imaging findings were first suggestive of a sarcomatous tumor. Laboratory work-up showed a markedly elevated alpha-fetoprotein (AFP) of 31,087 IU/l, LDH of 695 IU/l, and normal beta-HCG. Histopathology and immunohistochemistry (positive AFP, SALL4, and focal PLAP; negative OCT3/4 and CD30; Schiller-Duval bodies) confirmed a pure yolk sac tumor. The patient was referred to pediatric oncology but died within a few days from rapid clinical deterioration, before chemotherapy could be initiated.
Discussion: This case illustrates the diagnostic difficulty of this rare tumor, whose imaging features are non-specific and can mimic sarcoma, and underscores the central role of AFP as a diagnostic clue. It also illustrates the potentially fulminant course of locally advanced disease, requiring urgent multidisciplinary management from the time of clinical suspicion.
Conclusion: In any pediatric head and neck mass with rapid growth and an aggressive imaging pattern, systematic AFP measurement should be part of the first-line work-up alongside biopsy, in order to avoid missing an extragonadal yolk sac tumor and to shorten the time to oncologic treatment.
