Primitive neuroectodermal tumor presenting as a neck mass

T1 coronal magnetic resonance image demonstrated intraspinal tumor extending into the soft tissue of the lateral neck.

(A) Microscopic examination demonstrating a monomorphic sheet of undifferentiated small, blue, round cells with increased mitotic index and increased nuclear-cytoplasmic ratio. (B) Positive CD99 staining. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of the article.)