PMC5671704_01
Initial CT scan showing panhemispheric, mixed density subdural mass with significant mass effect ((a) and (b)). There is significant effacement of the right temporal horn and basilar cisterns consistent with herniation (c), though the 4th ventricle is still patent (d).
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fig1
Head CT (Figure 1) showed 1.5 cm right panhemispheric hyperdensity in the subdural space with significant midline shift, falcine herniation, uncal herniation, and loss of basilar cisterns.
Confluent, white mass seen on initial resection, the pathology of which returned as myeloid sarcoma.
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To the great surprise of the operating surgeon, upon dural opening, large clumps of confluent white material expressed themselves under pressure (Figure 2).
Immediate postoperative head CT showing complete resection of subdural hyperdensity (a) with loss of midline shift seen previously (b) and small subtemporal hematoma (c).
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After evacuation, the patient had intracranial pressure monitor placed and had a postoperative head CT (Figure 3).
Repeat CT 6 hours after first surgery showing reappearance of mixed density mass along the right convexity with again persistent midline shift ((a) and (b)). There is reherniation with loss of right temporal horn and basilar cisterns once again (c). Of note, the imaging characteristics of the small subtemporal hematoma are unchanged (d), speaking to the differing contents of the panhemispheric subdural density (versus hematoma) seen in panels (a) and (b).
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Thereafter, he began having progressively worsening ICP spikes, at which point repeat head CT was done (Figure 4), once again showing large accumulation of subdural mass.
Photomicrographs: low-power (a) and high-power (b) H&E stains showing lymphocytic invasion throughout the subdural space. Panels (c) and (d) show confluent immature myeloblasts consistent with myeloid sarcoma.
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Pathology revealed myeloid cells with immunohistochemistry staining negative for CD34 and CD117, consistent with mature myeloid sarcoma (Figure 5).