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[Extraaxial primary malignant lymphoma associated with calcified chronic subdural hematoma: a case report].

The authors report the case of a 54-year-old male with extraaxial primary malignant lymphoma associated with calcified chronic subdural hematoma. He slowly developed progressive headache accompanied by a bulge in the left forehead. Skull radiogram showed a large biconvex calcification in the left frontoparietal region, with concave change in the overlying bone. Computed tomograms and magnetic resonance images revealed a left frontoparietal chronic subdural hematoma surrounded by a calcified rim, with marginal enhancement in the frontal portion extending upward to the subcutaneous tissue through the underlying bone. The lesion was suspected to be an infectious calcified hematoma. The patient underwent a craniotomy for the removal of the hematoma. It was observed that the tumor was located mainly in the epidural and subdural space. The extent of the tumor corresponded with the enhanced area of the lesion in the preoperative neuroimages. The histological diagnosis was malignant lymphoma of B cell origin. General examination, which included bone marrow study and Ga scintigraphy, failed to prove systemic lymphoma. Extraaxial primary malignant lymphoma is extremely rare, and this is the first report of a lymphoma associated with calcified chronic subdural hematoma. The authors review the literature and discuss the clinical features and the pathogenesis of the lesion.