Pediatric benign osteocytic tumors include osteoma, enostosis, osteoid osteoma, and osteoblastoma. In pediatric populations, benign bone tumors are more common than malignancies. Benign osteocytic tumors may have a unique clinical presentation that helps narrow the differential diagnosis. A systemic imaging approach should be utilized to reach the diagnosis and guide clinicians in management. Radiographs are the most prevalent and cost-effective imaging modality. Cross-sectional imaging can be utilized for tissue characterization and for evaluation of lesions involving complex anatomical areas such as the pelvis and spine. Computed Tomography (CT) is the modality of choice for diagnosis of osteoid osteoma. CT scan can also be utilized to guide radiofrequency ablation, which has been found to be highly effective in treating osteoid osteoma and osteoblastoma. Enostosis is a no-touch lesion. Osteoma is commonly located in the paranasal sinuses. Osteoma needs an excision if it causes complications due to a mass effect.

Bone islands (BI; enostoses) may be solitary or occur in the setting of osteopoikilosis (multiple bone islands) and are sometimes associated with Gardner\'s Syndrome (osteopoikilosis and colonic polyposis). Characteristic features of bone islands are (1) absence of pain or local tenderness, (2) typical radio dense central appearance with peripheral radiating spicules (rose thorn), (3) Mean CT (computerized tomography) attenuation values above 885 Hounsfield units (HU) (4) absence of uptake on bone scan and (5) radiographic stability over time. However, when enostoses display atypical features of pain, unusual radiographic appearance, aberrant HU, increased radiotracer uptake, and/or enlargement, they can be difficult to differentiate from more sinister bony lesions such as osteoblastic metastasis, low grade central osteosarcoma, osteoid osteoma and osteoblastoma. In this retrospective case series, the demographic, clinical, radiographic, treatment and outcome for ten patients with eleven atypical bone islands (ABI) are presented, some showing associated pain (5), some with atypical radiographic appearance (3), some with increased activity on BS (4), some with documented enlargement over time (7), one with abnormal CT attenuation value, some in the setting of osteopoikilosis (2), one in the setting of Gardner\'s Syndrome and one osteoid osteoma simulating a bone island. This series represents the spectrum of presentations of ABI. Comprehensive review of the literature reveals that the previous largest series of ABI showing enlargement as the atypical feature was in younger patients with jaw BI. Hence, this represents one of the largest series reported of ABI of all types in adults.

Dense bone islands (DBIs) are usually asymptomatic and do not require any treatment. This case report presents a DBI of an unusual presentation, which was an incidental finding on a radiograph of a 15-year-old orthodontic patient. The DBI lesion was 24 mm in size, occupying at least 50% of the alveolar process between the upper right canine and lateral incisor, extending up the lateral aspect of the anterior margin of the right nasal fossa. Generally, DBIs are 2-3 mm in size and more commonly found in the mandible in the molar and premolar region. This article further discusses the impact of DBIs on orthodontic treatment such as difficulty with achieving space closure and adequate root tip or torque. We also examine the potential medical implications of DBIs. This is clinically important, especially if multiple DBIs, or osteomas which have a similar radiographic appearance to DBIs, are found in a patient as they may be associated with adenomatous intestinal polyps, which, if not treated, have a 100% chance of becoming malignant transformation.

OBJECTIVE: The objective of our study was to assess whether the maximum and mean CT attenuations are accurate for differentiating between enostoses and treated sclerotic metastases.
METHODS: We retrospectively reviewed CT studies of 165 patients (167 lesions) that included 49 patients with 49 benign lesions, 69 patients with 71 sclerotic treated lesions, and 47 patients with 47 untreated lesions, and calculated the mean and maximum CT attenuations of each lesion. ROC curves were used to identify thresholds for differentiating enostoses from treated sclerotic metastases and from untreated sclerotic metastases.
RESULTS: The maximum CT attenuation of enostoses (1212.0 HU) was higher from that of untreated (754.7 HU) (p = 9.7 × 10-16) and that of treated (891.7 HU) (p = 9.9 × 10-10) sclerotic metastases. The maximum CT attenuation of treated sclerotic metastases (891.7 HU) was higher than that of untreated sclerotic metastases (754.7 HU) (p = 0.003). Enostoses had higher mean CT attenuation (1123.0 HU) than untreated (602.0 HU) (p < 2.2 × 10-16) and treated (731.7 HU) (p = 9.6 × 10-15) sclerotic metastases. A threshold mean CT attenuation of 885 HU had an accuracy of 91.7% and 81.7% to differentiate enostoses from untreated and treated metastases, respectively, whereas a threshold maximum CT attenuation of 1060.0 HU had an accuracy of 81.3% and 72.5% to differentiate enostoses from untreated and treated metastases.
CONCLUSIONS: The mean and maximum CT attenuations can differentiate between enostoses and sclerotic metastases; however, the accuracy of both metrics decreases after treatment.

OBJECTIVE: The purpose of this study was to determine whether CT attenuation thresholds can be used to distinguish untreated osteoblastic metastases from enostoses.
METHODS: The study group comprised 62 patients with 279 sclerotic bone lesions found at CT (126 enostoses in 37 patients and 153 metastases in 25 patients). The cause of sclerotic lesions was assessed histologically or by clinical and imaging follow-up. None of the patients had undergone prior treatment for the metastases. The mean and maximum attenuation were measured in Hounsfield units. ROC analysis was performed to determine sensitivity, specificity, AUC, 95% CIs, and cutoff values of CT attenuation to differentiate metastases from enostoses. Interreader reproducibility was assessed using an intraclass correlation coefficient with 95% CI.
RESULTS: The mean and maximum CT attenuation values of enostoses were 1190 ± 239 HU and 1323 ± 234 HU, respectively, and those of osteoblastic metastases were 654 ± 176 HU and 787 ± 194 HU, respectively. Using a cutoff of 885 HU for mean attenuation, the AUC was 0.982, sensitivity was 95%, and specificity was 96%. Using a cutoff of 1060 HU for maximum CT attenuation, the AUC was 0.976, sensitivity was 95%, and specificity was 96%. The mean attenuation intraclass correlation coefficient was 0.987 for enostoses and 0.81 for metastases. The maximum attenuation intraclass correlation coefficient was 0.814 for enostoses and 0.980 for metastases.
CONCLUSIONS: CT attenuation measurements can be used to distinguish untreated osteoblastic metastases from enostoses. A mean attenuation of 885 HU and a maximum attenuation of 1060 HU provide reliable thresholds below which a metastatic lesion is the favored diagnosis.

A 29-year-old male patient reported for replacement of missing teeth. The patient gave history of unerupted right lower posterior teeth and the orthopantomogram revealed transmigrated mandibular second molar to the inferior border of mandible just below the root apices of second premolar associated with enostosis distally toward the ramus of mandible with size of about 21 mm Χ 20 mm. This rare interosseous defect plays a vital role in deciding prosthetic treatment options for missing teeth and utmost care should be taken to preserve the health of the patient during such procedures.

The \"Dense Bone Island\" (DBI) is a radiopaque lesion referred in leterature as idiopathic osteosclerosis, enostosis, focal osteosclerosis, periapical osteopetrosis, and bone scar. The DBI are accidentally found in routinary Xray of bone structures. In the maxillary bones, often localized in the mandible, especially in the molar region, with a reported incidence ranging from 2.3 to 9.7%. DBI does not seem to develop until the first phase of adolescence and it is usually found in adolescents and in young adults. In 40% of cases DBI seems to increase in size after a 10 year follow-up, because the DBI found in jaws and in long bones seem to increase proportionally to the bone growth. A case of a 26 years old patient and the surgical treatment is presented. This is the first reported case where complete X-ray Orthopantomography follow-up showed the evolution of the lesion since its onset.