Gross pathology photograph of the cranial vault (calvaria) from a 60-year-old male with plasma cell myeloma. The image demonstrates multiple round, punched-out lytic lesions scattered across the skull with destructive osteolysis of the calvarial bone. Lesions are variably sized, ranging from 1 to 4 cm in diameter, and are largely devoid of surrounding sclerosis. The affected bone shows pale, creamy to tan-rose, gelatinous tumor tissue within the radiolucent areas; the interior is soft and hemorrhagic, with scattered dark red foci representing microhemorrhages. The periosteum is disrupted in focal regions, and there is minimal inflammatory reaction. This macroscopic appearance reflects clonal proliferation of immunoglobulin-producing plasma cells occupying medullary spaces and replacing normal bone marrow. Clinically, such skull lesions are highly characteristic of multiple myeloma and can lead to pain, pathologic fracture, and neurological compromise if the skull base or spine is involved. The image provides a visual correlate for the classic punched-out radiolucencies described in hematologic malignancies and should be correlated with serum protein electrophoresis, immunofixation, and bone marrow biopsy. Differential considerations include metastatic skull lesions, Langerhans cell histiocytosis, osteomyelitis, and eosinophilic granuloma. This photograph is often used in educational materials to illustrate gross features of monoclonal gammopathy with skeletal involvement and to aid in teaching macroscopic recognition of myeloma.

This lateral skull radiograph (X-ray) demonstrates the classic 'punched-out' or 'moth-eaten' appearance characteristic of multiple myeloma. The image reveals numerous well-circumscribed, round-to-oval radiolucent (lytic) lesions of varying sizes distributed across the calvarium, including the frontal, parietal, and occipital bones. These lesions show no evidence of peripheral sclerotic margins, indicating aggressive bone resorption without significant reactive bone formation. The calvarial diploe is notably involved, showing a generalized decrease in bone density and disruption of the normal trabecular pattern. Clinical significance of these findings includes the hallmark skeletal manifestations of plasma cell dyscrasias, where monoclonal plasma cells infiltrate the bone marrow, triggering osteoclast activity. This diagnostic image serves as an educational example of hematologic malignancy-associated osteolysis and is a critical component of a skeletal survey for staging conditions like multiple myeloma or metastatic disease.

Gross pathology photograph of calvarial skull bones from a 60-year-old male with plasma cell myeloma showing multiple round lytic lesions. The skull base and vault are involved with discrete, punched-out defects ranging approximately 1 to 4 cm in diameter. The lesions are filled with soft, gelatinous red-brown tumor tissue, giving the inner table a slightly eroded appearance and thinning of the surrounding cortex. The overlying periosteum is variably preserved; surrounding diploic spaces may appear expanded and vascularized. The appearance is characteristic of osteolytic activity produced by clonal plasma cells that suppress normal bone formation and promote bone resorption, commonly involving the vertebral column, skull, ribs, pelvis, proximal long bones, and clavicles. In this specimen, the cranial vault bears multiple nodular foci with conspicuous dark hematopoietic plugs and subtle hemorrhagic foci. The gross features correlate with radiographic images of lytic skull lesions seen in multiple myeloma, or plasmacytomas, and reflect high tumor burden. Clinically, these findings support a diagnosis of multiple myeloma in the appropriate systemic context (anemia, hypercalcemia, renal dysfunction, monoclonal protein). Differential diagnoses include metastatic cancer and Langerhans cell histiocytosis. This image is useful for surgical pathology education, gross anatomy training, and radiology-pathology correlation exercises.