Hemangiopericytoma of neck extending to craniovertebral junction treated by surgery, pre- and postoperative radiotherapy
A 24-year-old female presented with a 1 year history of a painful, large, irregular, lobular mass rapidly growing at the nape of the neck, accompanied by decreased sensation/numbness in the C1-C2 dermatomes []. Computed tomography (CT) scans of both the head and neck revealed a moderately enhancing 10-12 cm lesion (in greatest diameter) extending from skull base to the thyroid gland. It additionally involved the posterior cervical muscles, eroded through the posterior arch of atlas and occipital bone, where it exhibited both extradural/intraspinal, and intracranial extension []. An incisional biopsy documented a highly vascular lesion consistent with a cellular variant of a solitary fibrous tumor (SFT) with HPC-like features. Preoperative RT was administered to reduce the size and vascularity of the tumor, and was followed by aggressive subtotal resection of an encapsulated, soft, vascular tumor. Notably, radical resection was limited by the tumor's depth and vascularity. Further postoperative RT resulted in a good clinical outcome.\nHistopathology revealed a vascular neoplasm characterized by sheets/groups of spindle/oval cells with a stag horn pattern consistent with HPC located in between plentiful of thin-walled vessels []. On immunohistochemistry, consistent with the diagnosis of HPC, the tumor cells were positive for both cluster of differentiation 34 (CD34) [] and vimentin []. The postoperative CT scan documented only a minimal amount of residual tumor (near the atlanto-occipital junction) with near complete decompression of the craniovertebral (CV) junction []. Two years postoperatively, the patient remains asymptomatic and disease free (e.g., no recurrence or metastases).