Metastatic Meningioma Presenting as Cancer of Unknown Primary
A 72-year-old Caucasian male patient was admitted to our hospital for excision of the metastatic adenocarcinoma of the skull vertex. It was diagnosed at an outside facility as carcinoma of unknown primary. He was initially diagnosed four years ago, when he presented to his primary care physician for worsening left hip pain, which was accompanied by mild muscular atrophy. A computerized tomographic (CT) scan demonstrated mixed sclerotic and lytic lesions in the left iliac wing. A bone scan demonstrated increased activity in the left sacroiliac joint. Magnetic resonance imaging (MRI) of lumbar spine showed abnormal signal in the left sacrum and ilium, consistent with metastatic disease. This area was biopsied and showed a metastatic poorly differentiated carcinoma, diffusely positive for widespectrum cytokeratin and negative for TTF1. Restaging studies did not demonstrate any other lesions. He was subsequently evaluated by radiation oncology and underwent radiation therapy to the left hip. The patient did well over the next 18 months, when he returned with an enlarged skull mass and received site directed radiation therapy. No biopsy of the skull mass was performed at this visit. He presented again in 6 months with a left tibial lesion for which he was treated with palliative radiation. A biopsy performed at this presentation did not demonstrate any neoplasm. Six-months later, he presented with increasing size of the skull mass and was initiated on chemotherapy with a regimen consisting of carboplatin and etoposide. He did have a moderate response to treatment. However, on follow-up, he was noted to have CT evidence of invasive and enlarging osseous metastasis measuring six centimeters (cm) involving the right frontal bone along with mild localized mass effect on the right frontal lobe. Consequently, he underwent another series of treatment with radiation therapy to the skull mass with a total dose of 35 grays (Gy). Despite an initial response to therapy, he subsequently had further progression of the calvarial mass including cutaneous breakdown, and presented to our institution for care.\nA nuclear medicine PET/CT of trunk showed an intensely FDG avid mass in the posterior left pelvis involving soft tissue and left iliac bone. Additionally, he underwent a subtotal resection of the skull mass, demonstrating anaplastic meningioma (). A CT guided biopsy of left iliac mass also revealed metastatic anaplastic meningioma. An octreotide scan () was performed revealing significant uptake in the left hip and right distal femur for which palliative radiation therapy was recommended, which was administered locally. However, he presented to a local ER soon after completion of radiation therapy with worsening left-sided weakness with CT evidence of cerebral edema. MRI revealed enhancing mass at the site of prior partial resection consistent with progressive disease (). He was no longer a candidate for surgery. Salvage radiation was attempted, but the patient continually to decline, and was ultimately enrolled in hospice for end of life care.