Objective and importance: Osteolytic lesions can be seen in various diseases, and they also resemble the markings normally found on the cranium. We present a rare case of symptomatic hypertrophic pacchionian granulation mimicking bone tumor in the calvaria.
Clinical presentation: A 46-year-old woman suffered from a small hump accompanied by pain in the right frontoparietal region. A plain radiograph revealed two punched-out lesions. Precontrast-enhanced computed tomographic scans demonstrated hypodense masses, with partial defect of the outer table of the cranium. Magnetic resonance imaging demonstrated hypointense masses in the T1-weighted image and hyperintense masses in the T2-weighted image, with capsule-like contrast enhancement by gadolinium diethylenetriamine penta-acetic acid.
Intervention: The masses were totally resected with attached bone and dura. One of them had destroyed the outer table of the cranium. The affected portions of the masses lacked the dura and partially adhered to the brain surface. Histologically, hypertrophic pacchionian granulation was diagnosed.
Conclusion: The patient has had no recurrence for 2 years. This case suggests the need to include hypertrophic pacchionian granulation in the differential diagnosis of punched-out lesions.