The classical clinical presentation of patients with osteoid osteoma involves the presence of localized pain (at the site of the tumor), and it is described as continuous, deep, and intense [10]. Depending on the localization of the tumor, patients may report pain in their arms [11], legs, feet, or hands in rare cases. In the majority of patients, pain is intensified during night time, and can sometimes wake the patient up, while other symptoms, such as restricted range of motion or local swelling may be observed. This tumor can present as arthritis in cases of phalangeal or wrist involvement [12], as well as macrodactyly and clubbing [13] [14]. In rare cases, if the tumor is located near the growth plate, limb overgrowth and discrepancy may be observed in young children. Sometimes the pain is considered to be of different origin, especially since this tumor occurs in teenagers and young adults, in whom pain can be prescribed to growth or some form of trauma, which can delay the diagnosis for weeks, and possibly years.

Physical examination will highly likely reveal the location of the tumor, and atrophy of surrounding muscles may be observed in patients who are experiencing severe pain, which can cause muscle misuse.

• Pain

  A minor trauma while playing basketball was reported, though the pain persisted over the following months. A pain diary was started and revealed pain levels of 5–7 on the Visual Analogue Scale (VAS) at rest, occurring predominantly at night. [bmcmusculoskeletdisord.biomedcentral.com]

  Aspirin or other NSAIDs frequently provide effective pain control, however, long-term therapy may be unacceptable because of refractory pain, recurrent nocturnal pain with resultant sleep deprivation, or gastrointestinal complications. [ijri.org]

  After the benign tumor develops further the pain can not be alleviated with medication and minor to severe swelling starts to occur. Although, in some cases the pain level remains the same for years, and regular NSAIDs intake keeps the pain at bay. [en.wikipedia.org]

  Complete relief of pain was noted within 24-48 hours; at 72 hours, the patients could stop taking analgesics. [emedicine.medscape.com]

  The pain was often dull and boring and frequently became worse at night. [jomfp.in]

• Swelling

  A 10-year-old boy presented with a swelling on the right side of the jaw. He had undergone excision of the lesion about 10 months ago at a private dental clinic and the swelling began to regrow 4 months after surgery. [ncbi.nlm.nih.gov]

  Case report A 40-yr-old male patient presented with swelling in the left upper front jaw region since 3 months. The swelling was gradual in onset and slowly increased in size to attain the present size. [ijp.iranpath.org]

• Surgical Procedure

  The difficulty of the surgical procedure is due to the deep localization of the osteoid osteoma and because it is endosseous, it is also dangerous due to anatomical relationships and the small size of the osteoid osteoma. [ncbi.nlm.nih.gov]

  Subsequent chapters cover nonsurgical treatments and surgical procedures. Concluding chapters cover pain, bone grafting, biomechanics, and outcomes assessment. [books.google.de]

  Surgical treatment For children with pain that cannot be relieved by over-the-counter medications, a procedure may be needed. The gold standard for treating osteoid osteoma is CT-guided radiofrequency ablation (RFA). [chop.edu]

• Localized Pain

  Clinical presentation involves intense localized pain, which is often not relieved by analgesics. [symptoma.com]

  In each case the principal complaint was of local pain, usually increasing and often severe enough to interfere with sleep. It was this symptom that brought the patients to consult a physician. 3. [jamanetwork.com]

  The local pain gradually diminishes. Indication for surgery depends on symptom severity and the patient's pain tolerance. With surgical resection, it has been emphasized that nidus removal is essential for pain relief. [atlasgeneticsoncology.org]

  175 ) Clinical features Intense localized pain, worse at night, relieved by NSAIDs Juxta - articular tumors with arthritis or joint dysfunction Vertebral tumors with scoliosis Diagnosis Intense pain and classic radiographic features Radiology description [pathologyoutlines.com]

  Local pain and tenderness is the presenting symptom in over 95% of cases. Scoliosis and torticollis may be presenting features in thoraco-lumbar and cervical spine regions. [ijri.org]

• Arthritis

  KEYWORDS: femur; juvenile idiopathic arthritis; needle biopsy; osteoid osteoma; radiofrequency ablation [ncbi.nlm.nih.gov]

  […] be the reason why aspirin works at relieving pain, by inhibiting PGE2 production) Tumors next to growth plates may increase growth and cause skeletal asymmetry Epiphyseal lesions may cause a joint effusion and clinical picture similar to rheumatoid arthritis [tumorsurgery.org]

  Osteoid osteoma mimicking chronic arthritis. Diagnosis by bone scintigraphy Hell J Nucl Med 2005 ; 8 : 171-173 [18] Aisen A.M., Glazer G.M. [em-consulte.com]

• Back Pain

  The possibility of osteoid osteoma should be kept in mind when examining adolescents with low back pain. [ncbi.nlm.nih.gov]

  Spine is an uncommon site for this benign tumor, and these patients are usually symptomatically treated for nonspecific back pain. [ccij-online.org]

  Lateral view of the lumbar spine in a 52-year-old man who had a biopsy-proven giant osteoid osteoma (osteoblastoma) and who presented with severe low back pain. [emedicine.medscape.com]

• Hip Pain

  The objective of this article was to emphasize the importance of including less common causes of hip pain in a differential diagnosis, particularly when clinical and radiographic variables are atypical. [ncbi.nlm.nih.gov]

• Bone Pain

  Osteoid osteomas are benign bone lesions that present with bone pain in children and young adults. Over the last 2 decades, radiofrequency ablation has become the mainstay of treatment and is now preferred over surgical resection. [ncbi.nlm.nih.gov]

  CONCLUSION Osteoid osteoma is a relatively common benign bone lesion in children and young adults that can present with nontraumatic bone pain. Depending upon the location of the lesion, it may be difficult to diagnosis. [appliedradiology.com]

  Bone scan – a nuclear imaging method to evaluate any degenerative and/or arthritic changes in the joints; to detect bone diseases and tumors; to determine the cause of bone pain or inflammation. [web.archive.org]

• Knee Pain

  The patient presented to our clinic after receiving multiple unsuccessful conservative and surgical interventions due to anterior knee pain, which persisted for 12months. [ncbi.nlm.nih.gov]

  The patient had worsening pain in the lateral knee, but no trauma was reported. Clinical examination revealed no signs of knee instability. [bmcmusculoskeletdisord.biomedcentral.com]

  When present, such vascular grooves have high sensitivity and specificity in the diagnosis of osteoid osteoma. 19 Figure 2: A 23-year-old man presented after 18 months of knee pain due to medullary osteoid osteoma. [healio.com]

  Clinical History: A 29 year-old female complains of progressive knee pain and stiffness without a history of trauma. A radiograph (not shown) demonstrated no abnormality. [radsource.us]

• Facial Pain

  pain over the past 6 months, which were aggravated at night. [ncbi.nlm.nih.gov]

• Confusion

  Diagnosis is challenging with clinical examination and usual imaging modalities and often confused with glomus tumor, enchondroma, infection, trauma and rheumatic disease. [ncbi.nlm.nih.gov]

  • MRI interpretation may result in errors in diagnosis, most often confusion with malignancies. 12. [slideshare.net]

• Irritability

  It is proposed that these nerve fibers can be stimulated by increased vascular pressure or direct irritation. [healio.com]

  Complications associated with this procedure include postoperative fracture, limitation of activity and impaired weight bearing for as long as 3 months after surgery, skin burns due to high rotation speed of the instrument, muscle hematoma, irritation [emedicine.medscape.com]

  But they can cause problems such as stomach irritation, ulcers, bleeding, high blood pressure, rash, and ankle swelling. They can sometimes also cause kidney or heart problems. [saintlukeshealthsystem.org]

• Trigeminal Neuralgia

  To retrospectively analyze clinical data of 4 patients with trigeminal neuralgia (TN) secondary to osteoid osteoma (OO) of the petrous bone and discuss treatment for this rare disease. [ncbi.nlm.nih.gov]

  Neuralgia Secondary to Osteoid Osteoma of the Petrous Bone: Report of 4 Cases and Brief Review of Literature. ( 29551722 ) Guo H....Bao Y. 2018 9 A misdiagnosed case of osteoid osteoma of L5. ( 28946543 ) Sheng X....Chu X. 2018 10 Radiofrequency ablation [malacards.org]

Clinical examination, as well as patient history, should point to a localized issue of the musculoskeletal system, and in all cases, imaging techniques are required to establish the diagnosis. Usually, a radiolucent area between 1-2 cm in diameter can be observed on plain X-ray, which can be surrounded by a halo ring that occurs as a result of bone sclerosis and cortical hypertrophy, which are hallmarks of osteoid osteoma. However, subperiosteal lesions may not be apparent, while both epiphyseal and metaphyseal lesions can show minimal or no sclerosing changes around the nidus, which is why CT scanning is recommended as the imaging technique of choice - to obtain a better view of the soft tissues, to exclude the presence of other types of tumors, and to serve as a guide to excision [15]. CT is superior to MRI, while radionuclide bone scanning with technetium-99m can be performed, since osteoid osteoma causes an uptake of isotope activity [16].

The definite diagnosis is achieved through a biopsy, which can be performed percutaneously, although results can be obtained in only 50% of the cases when samples through percutaneous techniques are obtained. For these reasons, a combination of clinical symptoms, as well as radiographic findings, is the key in order to diagnose osteoid osteoma. It is important to distinguish this benign bone tumor from other potentially debilitating, or sometimes life-threatening bone and joint illnesses such as osteomyelitis, arthritis, stress fractures, or osteoblastoma, which is also a benign tumor, and has almost identical features as osteoid osteoma.

Treatment strategies include pain-relieving therapy and localized surgical techniques to remove the tumor.

NSAIDs are the drugs of choice for the management of pain caused by osteoid osteoma, such as aspirin, presumably through inhibition of prostaglandin synthesis. Contraindications for use of NSAIDs exist, such as peptic ulcer disease, and for most patients, the pain becomes too intense and chronic [17], in which case other forms of treatment are necessary. However, pain management with NSAIDs can significantly defer surgical treatment.

Surgical excision of the nidus is the treatment of choice for patients in whom NSAIDs are insufficient. Localized percutaneous techniques provide immediate relief, and are curative in the vast majority of cases, with very low rates of recurrence. Curettage and unroofing of the nidus encompasses the gradual removal of the overlying bone that is covering the central part of the tumor and its subsequent removal. This procedure is preferred for patients whose tumor is located in more complicated locations, such as the femoral neck, and can help maintain structural support for the area, without disrupting the underlying bone.

In the majority of cases, however, radiofrequency ablation is the treatment of choice, through heat production and use of energy current, and has a very high rate of success [18]. Open surgery is reserved for patients in whom percutaneous techniques are not possible, for ex. if the tumor is in close proximity to other important structures (Such as the spinal canal, tumors that are located in hands, wrists, or feet), or because heat caused by ablation may damage the surrounding structures.

The prognosis of osteoid osteoma is good, since this tumor presents as a solitary lesion, has a relatively small diameter, and poses no metastatic potential. Treatment can be delayed, sometimes significantly, through the use of NSAIDs, but curative rates are very high with excision and localized percutaneous techniques, with the most effective one being radiofrequency ablation.

Osteoid osteoma is a benign bone-forming tumor that histologically appears as interlacing trabeculae of woven bone [6]. It is still unknown what the cause of the tumor is, and why are young adults in their second and third year most commonly affected.

This benign tumor comprises between 8-10% of all symptomatic benign bone tumors, and about 5% of all primary bone tumors. Osteoid osteoma is most commonly diagnosed in teens and young adults (between 10 and 30 years), but it can affect individuals of any age, while about 3% of cases occur in children younger than 5 years [7]. It is established that male individuals are more commonly affected, with a 2-3:1 ratio, while a racial predilection of this tumor has not been observed.

Osteoid osteoma is a tumor that usually involves the cortex of the bone, and is characterized by a central area called the nidus, which can potentially become sclerotic and mineralized, while the surrounding structures include interlacing trabeculae of woven bone and osteoblasts, as well as vascular connective tissue.

The pathogenesis of this tumor is still not completely understood, and several theories have been proposed, such as an inflammatory process (intracellular viral particles were observed on electron microscopy). The pain that is present in patients with this tumor includes generation of prostaglandins (which can account for intensifying pain during night time because of increased activity of prostaglandins during the night) [8], bradykinin, as well as vasodilation and edema, all contributing to stimulation of intraosseous nerve endings [9].

Having in mind the fact that the cause of this tumor is unknown, there is little to be done in terms of prevention, but it is a relatively benign lesion that can be successfully managed, and poses no threat for the patient.

Initially described in the 1930s [1], osteoid osteoma is a benign bone tumor, usually between 1.5-2 cm in diameter, that is characterized by a radiolucent central area - the nidus, and surrounding sclerosing bone, as well as loose vascular, connective and adipose tissue. It most commonly develops in young adults, usually in their second and third decades of life, with a 2:1 predilection towards the male gender, for unknown reasons [2]. It usually appears in the long bones, with the most common sites being the tibia and proximal femur [3], while other sites include the phalanges, bones of the foot, and the vertebrae. Clinical presentation almost universally involves the presence of intense localized pain that intensifies at night. The diagnosis is achieved through imaging techniques, such as plain radiography or computed tomography (CT), while magnetic resonance imaging (MRI) can also be used, while radionuclide scanning can be effective in distinguishing osteoid osteoma from other tumors of the skeletal system [4]. This benign tumor does not metastasize, and is usually treated by percutaneous techniques, such as local excision, curettage, or radiofrequency ablation, while open surgery is rarely indicated. Non-steroidal anti-inflammatory drugs (NSAIDs) can be helpful in relieving pain, and surgical treatment may be replaced through the use of these medications, as the tumor does not pose a threat to the patient [5].

Osteoid osteoma is a small benign solitary tumor of the bones which occurs in individuals during their second and third decade of life, and is diagnosed more frequently in males. It is still not known why this tumor appears. It usually develops in the bones of the lower extremities, but it can appear on any bone in the body, including the arms, hands, feet, and the spine. Virtually all patients report severe localized pain at the site of the tumor, because the central part of the tumor - the nidus - produces intense pain. The majority of patients describe the pain as sharp, intense, and more often during the night, which may even wake up the patient. Limb asymmetry and unequal growth may be observed if the tumor is located inside the growth plate, while muscle atrophy can occur in patients who avoid using their extremity because of severe pain.

The diagnosis of osteoid osteoma is made based on findings made during the clinical examination, and imaging techniques. A plain X-ray may reveal the tumor, while computed tomography (CT scan) is the recommended imaging technique, because it can provide a good view of the bone and surrounding soft tissues. Once the diagnosis is made, treatment principles primarily include pain relieving, through the use of non-steroidal anti-inflammatory drugs, such as aspirin, which can defer other forms of therapy for a prolonged period of time. However, since the majority of patients cannot tolerate pain even with appropriate medication, certain types of minimally invasive surgical techniques are performed, usually under local anesthesia. Excision of the tumor can provide permanent relief, and rates of recurrences are minimal. This tumor is benign in origin, has no potential to become malignant and metastasize, and can be successfully treated.

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