Young adults are most frequently affected by OB, and patients typically seek medical attention for dull bone pain. Soft tissue and bony swelling may be noted at the site of the lesion. A general predilection for the axial skeleton has been observed [4], and up to 40% of cases involve the spine, mainly the vertebral arches of the lumbar region [5]. Nevertheless, OB may also develop in the appendicular skeleton, affecting the long bones of arms and legs or distal parts of the limbs [6].

OB exert local mass effects and accordingly, patients may present with spinal cord compression, radiculopathy, visual impairment and additional neurological deficits [7], stiffness and reduced joint motion ranges, among others. Lateral deviations of the spine and other deformities may be observed [8].

• Pain

  The tumor may cause pain, erosion, and resorption of native bone. Excision is the preferred treatment. [medical-dictionary.thefreedictionary.com]

  […] not as readily relieved by salicylates as in osteoid osteoma Pain may be present at rest, but does not usually have nocturnal worsening commonly associated with osteoid osteoma Patient may be asymptomatic, but pain is generally predominant feature Spinal [orthopaedicsone.com]

  The patient presented with a painful, firm, non-tender mass in his left thigh. The pain was worse at night and was temporarily relieved with NSAIDS. He had no fevers, night sweats, or weight loss. [ncbi.nlm.nih.gov]

  Clinical examination revealed a firm, painful, poorly differentiated swelling of the ulnar side of the wrist. The fingers and wrist were stiff and tender and the skin was bluish and shiny, suggesting a complex regional pain syndrome. [em-consulte.com]

• Swelling

  A 32-year-old female presented with a rapidly increasing swelling in left mastoid region for 6 months. During initial 2 months there was only pain in mastoid region which was followed by development of swelling. [ijpmonline.org]

  We present a case of a 19-year-old man with left shoulder pain for 1 year, with associated infraclavicular swelling for 8 months. Examination revealed a tender, bony, hard swelling measuring 3×4 cm. [ncbi.nlm.nih.gov]

• Inflammation

  Computed tomography is the preferred imaging modality as it is able to detect the nidus and images will not exhibit the flare phenomenon caused by surrounding inflammation seen with magnetic resonance imaging. [ncbi.nlm.nih.gov]

  […] computer to produce detailed images of organs and structures within the body 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 [childrenshospital.org]

  Trauma, inflammation, abnormal local response of the tissues to injury, and local alteration in bone physiology are few of the other reasons cited in the literature pertaining to the etiology of this tumor. [sidj.org]

• Military Personnel

  The identification of this unique tumor solely in military personnel is likely due to the relatively high proportion of young males represented in the military, the demographic most likely to develop osteoblastomas. [ncbi.nlm.nih.gov]

• Fatigue

  Other common acute side efects include gastrointestinal upset, urinary frequency, fatigue, anorexia, and extremity edema. Late efects include chronic edema, ibrosis, osteonecrosis, and pathological fracture. [brainscape.com]

• Vomiting

  A 30-year-old female was admitted to our hospital, because of the mass in the right frontal region with the history of headache for 3 years without nausea or vomiting. [ncbi.nlm.nih.gov]

  The pain was localized in the forehead and was not accompanied by nausea or vomiting. Written informed consent was obtained from the patient for publication of this case report and any accompanying images. [spandidos-publications.com]

• Nausea

  A 30-year-old female was admitted to our hospital, because of the mass in the right frontal region with the history of headache for 3 years without nausea or vomiting. [ncbi.nlm.nih.gov]

  The pain was localized in the forehead and was not accompanied by nausea or vomiting. Written informed consent was obtained from the patient for publication of this case report and any accompanying images. [spandidos-publications.com]

• Toothache

  The history revealed that the patient noticed a slow-growing swelling on the left lower side of the face for 5 years with no history of trauma, toothache, pain, or discharge from the swelling. [jiaomr.in]

• Blurred Vision

  Osteoblastoma of the frontal sinuses presenting with headache and blurred vision: Case report and review of the literature. J Radiol Case Rep 2010;4:1-7. 6. Bilkay U, Erdem O, Ozek C, Helvaci E, Kilic K, Ertan Y, et al. [njcponline.com]

• Back Pain

  Surgical resection of the lesion confirmed a benign osteoblastoma. 12 months follow-up revealed disappearance of right back pain. [ncbi.nlm.nih.gov]

• Osteoporosis

  The book details the pathologic and radiologic characteristics of all bone and joint diseases, including arthritis, metastatic bone disease, osteoporosis, trauma, osteomyelitis, developmental bone disorders, and tumor-like lesions. [books.google.com]

  Comprehensive health information about cancer, osteoporosis, high blood pressure and more. Comprehensive health information including health news updates and health resources. [web.archive.org]

  Indeed, spotty osteoporosis, which is characteristic of a complex regional pain syndrome, was already present when the fracture occurred. Moreover, this syndrome rapidly and clearly improved after curettage biopsy. [em-consulte.com]

  Regional osteoporosis in osteoid osteoma. J. Bone Joint Surg., 43B: 501 – 507, 1961. Google Scholar 48.. Unni, K.K., Dahlin, D.C.: Premalignant tumors and conditions of bone. Am. J. Surg. Pathol., 3: 47 – 60, 1979. [journals.sagepub.com]

  Spence AJ, Lloyd-Roberts GC (1961) Regional osteoporosis in osteoid osteoma. J Bone Joint Surg [Br] 43-B:501 Google Scholar 107. Spencer MG, Mitchell DB (1987) Growth of a frontal sinus osteoma. J Laryngol Otol 101:726 Google Scholar 108. [link.springer.com]

• Bone Disorder

  The book details the pathologic and radiologic characteristics of all bone and joint diseases, including arthritis, metastatic bone disease, osteoporosis, trauma, osteomyelitis, developmental bone disorders, and tumor-like lesions. [books.google.com]

• Aggressive Behavior

  Osteoblastoma is a benign tumor with an aggressive behavior. The treatment is wide surgical resection, otherwise it continues to enlarge and destroy the bone and surrounding structures. [ncbi.nlm.nih.gov]

  Histological and immunohistochemical evaluation associated with clinical and imaging findings allowed to define the tumor as an aggressive variant of osteoblastoma and not osteosarcoma, despite the aggressive behavior. [journals.lww.com]

• Confusion

  Although most osteoblastomas are considered benign, a controversial aggressive variant has been described, which may cause diagnostic confusion with malignant tumors such as osteosarcoma. [ncbi.nlm.nih.gov]

  It should not be confused with the so-called “ossifying fibroma” which is apparently closely related to fibrous dysplasia and usually localized in the maxilla or the mandible (3). [pubs.rsna.org]

• Hyperactivity

  Muscle stretch reflexes of the upper extremity were hyperactive, and normal for the lower extremity. [nature.com]

Diagnostic imaging is required to confirm the presence of an osseous mass, to determine its extension and to identify possibly compromised adjacent structures. Plain radiography and computed tomography are most commonly employed and yield reliable results. Here, OB present as discrete lesions comprising both lytic and sclerotic regions [9]. Soft tissue involvement may be better assessable applying other imaging techniques.

A histopathological examination of biopsy specimens is crucial for the diagnosis of OB. In this context, it is important to obtain representative samples that ideally measure several millimeters in size. Fine-needle aspirates are usually insufficient. OB are hypocellular, mineralized tumors consisting of irregular, largely immature trabecular bone [7]. Giant cells may be present. There are no apparent differences between central and peripheral areas of the tumor. Lesions are well demarcated, and this feature helps to distinguish OB from osteosarcoma. However, the transition from benign OB to malignant osteosarcoma is smooth and aggressive types of OB have been described [10].

Based on radiological findings and histopathological analyses alone, the distinction between OB and osteoid osteoma may pose a major challenge. Still, a precise diagnosis is of major prognostic and therapeutic relevance: OB have considerable malignant potential, may show locally aggressive behavior,and recurrence is more likely than in patients diagnosed with osteoid osteoma [5]. Clinical criteria should be considered to support a tentative diagnosis of either bone tumor [4]:

• OB usually develop in the axial skeleton, while osteoid osteomas primarily affect the long bones of the limbs.
• Persistent bone pain is characteristic of OB, whereas osteoid osteoma patients frequently experience pain that worsens at night.
• In patients suffering from osteoid osteoma, pain may be relieved by salicylates, but this is rarely the case in individuals suffering from OB.
• Both are most commonly diagnosed in young adults but may affect patients of any age.

Conservative treatment with anti-inflammatory medications before referral was unsuccessful. The authors present the diagnostic difficulties and the treatment that was applied: proximal row carpectomy. [ncbi.nlm.nih.gov]

Osteoblastoma: When the Treatment Is Not Minimally Invasive, an Overview. [mdpi.com]

This case delineates the difficulties in diagnosing this tumor, the challenges and problems encountered during its surgical management, and the favorable prognosis after adequate treatment. [ncbi.nlm.nih.gov]

In general, osteoblastoma has a good prognosis, and patients are often cancer-free after surgical treatments of intralesional curettage or marginal en bloc resection. [pubmed.ncbi.nlm.nih.gov]

Total resection should be advocated whenever possible, due to good prognosis and relatively low recurrence, even in the recurrent cases. [indianjotol.org]

In conclusion, the differential diagnosis for vertebra plana is extensive and we add spinal osteoblastoma as another etiology to the existing list. [ncbi.nlm.nih.gov]

Epidemiology Incidence relatively rare less common than osteoid osteoma Demographics males > females (2:1) majority of patients 10-30 years of age Anatomic location most common in posterior elements of spine Etiology Genetics unknown Associated conditions [orthobullets.com]

The exact etiology of osteoblastoma is unknown. Epidemiology In the United States, osteoblastoma accounts for approximately 1% of all primary bone tumors. [emedicine.medscape.com]

Etiology of osteoblastoma is unknown; however it is considered to be a true neoplasm of bone (3). Itmost commonly affects vertebral column, sacrum, calvarium, long bones and small bones of hand and feet. [ijp.iranpath.org]

Basic demographic and epidemiological data were recorded. Tumor characteristics, surgical parameters, and clinical follow-up data were noted. RESULTS: The mean follow-up was 21.9 months. [ncbi.nlm.nih.gov]

Epidemiology Incidence relatively rare less common than osteoid osteoma Demographics males > females (2:1) majority of patients 10-30 years of age Anatomic location most common in posterior elements of spine Etiology Genetics unknown Associated conditions [orthobullets.com]

Epidemiology In the United States, osteoblastoma accounts for approximately 1% of all primary bone tumors. [emedicine.medscape.com]

The epidemiological aspects, size of the disease and site of onset, symptoms, surgery type, indications, and results are reported for every case. Results: all treatments were based on a preoperative diagnosis; pain was constant in all cases. [mdpi.com]

The pathophysiology of symptom development, evaluations, and management are presented. Because of the close proximity of the osteoblastoma to the vertebral artery canal, the artery suffered a minor laceration intraoperatively. [ncbi.nlm.nih.gov]

[citation needed] Pathophysiology[edit] The cause of osteoblastoma is unknown. [en.wikipedia.org]

Pathophysiology and Etiology Regardless of where osteoblastomas originate within the musculoskeletal system, they are composed of numerous osteoblasts that produce osteoid and woven bone. [emedicine.medscape.com]

Preoperative embolization was performed to reduce intraoperative bleeding and to prevent intraoperative injury of the vertebral artery. A pathologic examination showed osteoblasts suggestive of osteoblastoma. [ncbi.nlm.nih.gov]

Osteoblastoma (OB) is a rare type of neoplasm, accounting for approximately 1% of primary bone tumors [1]. OB are benign tumors originating from osteoblasts, and they are characterized by their ability to produce osteoid. Thus, they form large masses with diameters exceeding 2 cm that exert local mass effects on adjacent tissues. Because OB most frequently affect the axial skeleton, central nervous system compromise is frequently seen in affected individuals. Furthermore, OB have been reported to undergo malignant transformation [2]. Still, OB patients generally have a good prognosis and most of them are cured by means of a complete surgical resection of the neoplasm [3].

1. Lucas DR. Osteoblastoma. Arch Pathol Lab Med. 2010; 134(10):1460-1466.
2. Kraft CT, Morrison RJ, Arts HA. Malignant transformation of a high-grade osteoblastoma of the petrous apex with subcutaneous metastasis. Ear Nose Throat J. 2016; 95(6):230-233.
3. Boriani S, Amendola L, Bandiera S, et al. Staging and treatment of osteoblastoma in the mobile spine: a review of 51 cases. Eur Spine J. 2012; 21(10):2003-2010.
4. Greenspan A. Benign bone-forming lesions: osteoma, osteoid osteoma, and osteoblastoma. Clinical, imaging, pathologic, and differential considerations. Skeletal Radiol. 1993; 22(7):485-500.
5. Kurugoglu S, Adaletli I, Mihmanli I, Kanberoglu K. Lumbosacral osseous tumors in children. Eur J Radiol. 2008; 65(2):257-269.
6. Li Z, Zhao Y, Hou S, Mao N, Yu S, Hou T. Clinical features and surgical management of spinal osteoblastoma: a retrospective study in 18 cases. PLoS One. 2013; 8(9):e74635.
7. Caltabiano R, Serra A, Bonfiglio M, et al. A rare location of benign osteoblastoma: case study and a review of the literature. Eur Rev Med Pharmacol Sci. 2012; 16(13):1891-1894.
8. Poleksic ZR, Lalosevic VJ, Milinkovic ZB. Osteoblastoma of the spine. Acta Chir Iugosl. 2010; 57(1):63-68.
9. Pelargos PE, Nagasawa DT, Ung N, et al. Clinical characteristics and diagnostic imaging of cranial osteoblastoma. J Clin Neurosci. 2015; 22(3):445-449.
10. Harrington C, Accurso BT, Kalmar JR, et al. Aggressive osteoblastoma of the maxilla: a case report and review of the literature. Head Neck Pathol. 2011; 5(2):165-170.