Primary undifferentiated sarcoma of the meninges: A case report and comprehensive review of the literature.

BACKGROUND AND IMPORTANCE: Sarcomas make up 1% of all cases of adult cancer, with 5-10% of those classified as undifferentiated pleomorphic sarcomas (UPS/PUS) and 0.1-4.3% primary intracranial sarcomas. Intracranial undifferentiated sarcoma is characterized by an earlier age of onset and generally poorer prognosis compared to extracranial undifferentiated sarcomas. Current therapies involve surgical excision with wide margins and radiotherapy, with minimal data available regarding the efficacy of chemotherapy.

CASE DESCRIPTION: A 79-year-old man with a history of remote superficial bladder cancer presented with a large frontal scalp lesion. A biopsy was initially attempted by a dermatologist in the outpatient setting, but a follow-up CT scan revealed a skull-eroding, enhancing soft tissue lesion. Neurosurgical treatment revealed an undifferentiated sarcoma. The patient underwent adjuvant radiation therapy of 59.4 Gy fractionated over 45 days following surgery. Follow-up brain MRIs at 1-, 6-, 9-, 12-, 15-, 21-, and 27 months after surgery have not shown any indications of local recurrence or tumor metastasis. Despite the high propensity that undifferentiated sarcomas have for recurrence and metastasis and the patient's advanced age, this patient remains uniquely disease-free.

CONCLUSION: We provide a description of an unusual case and comprehensive literature review of UPS to clarify the hallmarks of the disease, identify the difficulties in diagnosis, and provide a summary of therapies employed in the literature with their corresponding patient outcomes.