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Summary: Tumor-induced osteomalacia (TIO) is a rare form of osteomalacia caused by fibroblast growth factor-23 (FGF23)-secreting tumors. Most of these tumors are phosphaturic mesenchymal tumors (PMTs) typically involving soft tissue in the extremities and bone of the appendicular skeleton and cranium. We report the case of a 60-year-old woman with about 3 years of persistent bone pain and multiple fractures, initially diagnosed as osteoporosis, who was found to have hypophosphatemia with low 1,25-dihydroxyvitamin D and elevated alkaline phosphatase and inappropriately normal FGF23 consistent with TIO. Her symptoms improved with phosphate supplementation, vitamin D and calcitriol. 68Ga-DOTATATE imaging revealed a T12 vertebral body lesion confirmed on biopsy to be a PMT. She underwent resection of the PMT with resolution of TIO and increased bone density. This rare case of TIO secondary to a PMT of the thoracic spine highlights some of the common features of PMT-associated TIO and draws attention to PMT-associated TIO as a possible cause of unexplained persistent bone pain, a disease entity that often goes undiagnosed and untreated for years. Learning points: Tumor-induced osteomalacia (TIO) is typically caused by phosphaturic mesenchymal tumors (PMTs) that are usually found in the soft tissue of the extremities and bone of the appendicular skeleton/cranium and rarely in the spine. TIO may be misdiagnosed as osteoporosis or spondyloarthritis, and the correct diagnosis is often delayed for years. However, osteoporosis, in the absence of fracture, is not associated with bone pain. The hallmark of TIO is hypophosphatemia with inappropriately normal or low 1,25-dihydroxyvitamin D and elevated or inappropriately normal fibroblast growth factor-23 (FGF23) levels. In patients with unexplained persistent bone pain, a serum phosphate should be measured. Consider PMT-associated TIO as a potential cause of unexplained persistent bone pain and hypophosphatemia. PMTs express somatostatin receptors and may be identified with 68Ga-DOTATATE imaging. Complete surgical resection is the preferred treatment for spinal PMTs associated with TIO.
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OBJECTIVE: To report a case of petrous apicitis that manifested as chronic migraine without aura and to discuss the pathophysiological mechanisms behind this presentation. BACKGROUND: Petrous apicitis is a rare complication of acute otitis media with varied clinical presentations that stem from the close proximity of the petrous apex to numerous neurovascular structures. Headache is among the common symptoms of petrous apicitis. METHODS: A case of new onset headache in the setting of petrous apicitis with symptomatic response to antibiotic therapy was reported. We provided a brief review of peripheral pathophysiological mechanisms of migraine and correlated to mechanism of headache in petrous apicitis. RESULTS: A 65-year-old man with chronic otitis externa/media presented with ongoing headache fulfilling International Classification of Headache Disorders 3rd edition (ICHD-3) criteria for chronic migraine without aura that persisted despite undergoing right mastoidectomy and tympanoplasty with multiple courses of oral antibiotic therapy for his chronic otitis. MRI brain revealed petrous apicitis, otomastoiditis, and clival osteomyelitis. His imaging findings improved and his migraine-like headache completely resolved after treatment with a prolonged course of antibiotics. CONCLUSIONS: Petrous apicitis can present as a headache with features of migraine, and in this case in particular, as chronic migraine without aura. The pathophysiological mechanisms that may underlie the generation of migraine-like headache in petrous apicitis may include the activation of nociceptive fibers within the periosteum of the petrous apex and clivus whose cell bodies originate in the trigeminal ganglion and upper cervical dorsal root ganglia. By treating the peripheral pathology, resolution of the headache may be achieved.