Immunostaining was done with appropriate positive and negative controls and revealed:
Referred blocks for immunostaining of biopsy due to pathologic fracture of the left humeral neck, MRI-identified cystic lesion. The case was diagnosed by pathology number 1819-2026 as malignant round cell tumor suspicious for plasma cell myeloma, recommended for definitive typing by marker study, on 2 April 2026.
Two referred paraffin blocks coded 1819-2026.
Lt. Humeral neck lytic lesion: