Fig. 1

a Patient 1, chest CT scan demonstrating new thoracic and lumbar compression fractures, evolving over one year on immunotherapy, 2016 compared to 2017 (bracket); new sternal deformity in the setting of marked kyphosis with compensatory sternal compression (arrow). b Patient 1, transiliac bone biopsy photographed at 400×; top panel illustrates thin trabeculae and limited connectivity, consistent with osteoporosis (arrow); middle panel demonstrating increased osteoclastic activity at the sites of three Howship’s lacunae, or resorption pits (stars); bottom panel outlines histomorphometry parameters including increased eroded surface as well as decreased trabecular and cortical thickness but increased trabecular separation consistent with low bone mass