Intraosseous pneumatocyst of the ilium: CT findings in two cases and literature review

Abstract

Intraosseous pneumatocyst of the ilium is a rare lesion of uncertain origin. It predilects male subjects and may be associated or not with sacroiliac joint degenerative disease, intra-articular gas, sacral pneumatocyst, and communication with the articular space. To our knowledge, only 16 observations have been reported in the literature. We have evaluated with plain radiographs and CT two additional cases. Plain films frequently identify these lesions, but CT is the method of choice in demonstrating their air density and assessing the possible abnormalities of the surrounding bone and sacroiliac joints.

Sacroiliac joint pneumatocysts: prevalence on CT examinations

“…They were not seen in any patient younger than 35 years of age in our series. Communication of the cysts with the joint space is an issue of controversy in the literature [1,2]. This finding was not observed in any case in our series.…”

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The interesting article by Catalano et al [1] described the CT findings of sacroiliac joint (SJ) pneumatocysts in two patients and presented data from 16 other cases previously reported in the literature. According to our experience SJ pneumatocysts are not uncommon and they can incidentally be observed on pelvic CT examinations when using bone window settings.

We have prospectively evaluated 369 consecutive patients (160 men and 209 women, 22±83 years of age) referred for pelvic CT with various indications, mostly related to pelvic malignancies.

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“…The interesting article by Catalano et al [1] described the CT findings of sacroiliac joint (SJ) pneumatocysts in two patients and presented data from 16 other cases previously reported in the literature. According to our experience SJ pneumatocysts are not uncommon and they can incidentally be observed on pelvic CT examinations when using bone window settings.…”

Lésion osseuse de nature rare

“…Le pneumatokyste osseux est généralement situé au niveau de l'aile iliaque et du sacrum, mais peut aussi se trouver au niveau des vertèbres ou de la clavicule. Il est à prédominance masculine, généralement asymptomatique et ne nécessite pas de traitement spécifique [1][2][3][4]. Son étiopathogénie est discutée.…”

Vertebral Pneumatocysts

“…This benign entity is a cyst‐like lesion of gas attenuation, with a sclerotic rim and with or without adjacent joint communication (14, 15). The pneumatocyst is usually seen in the iliac bone or sacrum (4, 14, 15) and rarely in the cervical vertebrae, humeral head or clavicle (6, 7, 11–13).…”