OBJECTIVE AND IMPORTANCE: Osteolytic lesions can be seen in various di
seases, and they also resemble the markings normally found on the cran
ium. We present a rare case of symptomatic hypertrophic pacchionian gr
anulation 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 punc
hed-out lesions. Precontrast-enhanced computed tomographic scans demon
strated hypodense masses, with partial defect of the outer table of th
e cranium. Magnetic resonance imaging demonstrated hypointense masses
in the T1-weighted image and hyperintense masses in the TZ-weighted im
age, with capsule-like contrast enhancement by gadolinium diethylenetr
iamine penta-acetic acid. INTERVENTION: The masses were totally resect
ed with attached bone and dura. One of them had destroyed the outer ta
ble of the cranium. The affected portions of the masses lacked the dur
a and partially adhered to the brain surface. Histologically, hypertro
phic pacchionian granulation was diagnosed. CONCLUSION: The patient ha
s had no recurrence for 2 years. This case suggests the need to includ
e hypertrophic pacchionian granulation in the differential diagnosis o
f punched-out lesions.