Raindrop skull is a feature of?

Ans. A. Multiple myelomaMULTIPLE MYELOMAMost common primary malignant neoplasm in adults, which is followed by osteosarcoma.Age: usually 5th to 8th decadeLocation:Disseminated form: vertebrae > ribs > skull > pelvis > long bones Solitary Plasmacytoma: Vertebrae > pelvis > skull > sternum > ribsRadiographic features:a. Multiple punched out widespread osteolytic lesions in skull, however classic 2-3mm 'rain drop' circular lytic defects are not always evidentb. But Mandibular involvement may be helpful indistinguishing it from metastasesc. Blown out lesions of skull, long bones (persistent red marrow areas of proximal femora and humeri) and pelvisd. Soft tissue masses adjacent to area of lysis may be seene. Localized areas of lucency in red marrow areas and generalized osteoporosis are tow cardinal featuresf. Diffuse osteoporosis can alone cause suspicion of this disease in an elderly patientg. Spinal myeloma: sparing of posterior elements, intervertebral disc spaces and articular surfaces with paraspinal soft tissue massh. Sclerotic lesions are rare in multiple myelomai. It is still one of the indications for skeletal survey in today's era of modern imaging.Bone Scan featuresIn multiple myeloma, 99m Tc products do not localize well in the destructive/lytic lesions (no osteoblastic activity, hence no uptake - cold spots).