I have Bone Island (aka Enostosis)

That is my OPG taken twice on 27 February and 13 March on 2017. Purpose of the first radiograph was taken to diagnose either both lower left and right 3rd molar is impacted or not but accidentally the bone island is diagnose. (* Regarding the third molar, radiograph was taken because clinically it seem like impacted but in radiograph, we diagnose it as operculum reside on top of the teeth.) Then, second radiograph was taken to look if the lesion show any changes and further investigations need to be done if the changes is positive.

I do some research on the internet that the bone island is not harm and is only benign. Only in rare cases will show more than 2 cm with symptoms. I did not feel pain before, and for my case I just acting like a surrender right now to wait any symptoms to appear if it happen. 

Then, basically the lesions are usually associated in long bone but for mine it is located at my mandible. So based on what I found, my case is rare, maybe.

Here are some of the points that I found so interesting to understand in detail about bone island:

DEFINITION AND PATHOGENESIS

• A benign, rarely symptomatic lesion, usually very small, of unknown etiology

IMPORTANCE

• Commonly found incidentally, and can be mistaken for lesions which require bx

CLINICAL FEATURES

• Usually asymptomatic
• Symptomatic lesions may become asymptomatic
• Most common in pelvis, ribs, proximal femur
• M = F
• Has been reported in Bannayan-Riley Ruvalcaba syndrome
• A higher incidence of bone islands has been reported in the hands and feet of pts with lepromatous leprosy and borderline types of leprosy but not in tuberculoid leprosy

RADIOLOGIC FEATURES

• 2mm-2cm sized round to oval blastic lesion blends with the cancellous bone in a "brush-like" manner
• Bone scan is cold or only warm (33% >15mm reported active on bone scan)
• CT scan will show the blastic nature of the lesion, accurately give dimensions, and demonstrate lack of periosteal reaction
• No surrounding bony destruction/cortical disruption, IM extension, or soft tissue mass associated with the lesion is best demonstrated with MRI (hypointense on T1 and T2)

GROSS PATHOLOGY

• Sharply defined hard lesion within the IM canal

HISTOLOGIC FEATURES

• Appearance of misplaced cortical bone within the IM canal: thick lamellar bone with Haversian systems
• No host bone lamellar bone trapping (seen in callus and osteosarcoma)
• No atypical nuclei or mitoses

DIFFERENTIAL CLINICOPATHOLOGIC DIAGNOSIS

• Metastatic bone disease (esp. with multiple lesions, eg, blastic breast mets or prostate CA)
• Osteoid osteoma
• Osteoblastoma
• Enchondroma
• Bone infarct
• Fibrous dysplasia
• Osteomyelitis
• Osteosarcoma

DISEASE COURSE AND TREATMENT

• Usually require no tx
• FU x-ray in one month and every 3 months (X4) in questionable lesions
• Biopsy in larger lesions to R/O osteosarcoma or in lesions that have size ? > 25% within 6mos, or >50% at 1yr

Source

http://www.orthopaedicsone.com/pages/viewpage.action?pageId=19071118