PMC6059655_01
CT head showing enlarged right frontal scalp mass. A: axial view non-contrast, B: axial view with contrast, C: Coronal view with contrast.
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F1
Because of the hip pain and nodules, he came to the emergency department where a CT scan showed an enlarged right frontal scalp mass that measured about 4 cm (Figure 1).
MRI showing scalp mass, vasogenic edema, and midline shift. A: Axial view T1 no contrast, B: Axial view T1 with contrast.
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F2
MRI also revealed a right frontal scalp mass and extensive vasogenic edema localized to the right frontal lobe with a 5 mm midline shift at the foramen of Monroe (Figure 2).
Nuclear medicine bone scan with 99mTc-hydroxymethylene diphosphonate (HMDP) and SPECT showed multiple areas of uptake concerning for malignancy. Uptake shown in right posterior iliac bone.
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F3
A follow-up nuclear medicine bone scan demonstrated multiple areas of increased uptake concerning for metastasis (Figure 3).
Histopathologic staining showing monotonous infiltrate composed of small cells with irregular nuclei, condensed chromatin, and inconspicuous nucleoli.
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F4
Histopathology of the biopsy showed a diffuse and monotonous infiltrate composed of small cells with irregular nuclei, condensed chromatin and inconspicuous nucleoli (Figure 4).
Immunohistochemistry showing cells that are CD20 positive and co-express CD10 and Bcl2.
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F5
CD20 positive B-cells and co-express CD10 and Bcl-2 but do not express CD3, 5, 23, 43 and cyclin D1 (Figure 5). CD21 was present highlighting a disrupted follicular dendritic cell meshwork.