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].

• Dysphagia

  We present the first known case of osteoblastoma arising in the hyoid bone, in a patient who presented with a neck mass and dysphagia. [ncbi.nlm.nih.gov]

  Laryngeal osteoblastoma usually presents as an inflammatory tumour which, as it progresses slowly, causes dyspnoea, dysphagia, and/or dysphonia. [elsevier.es]

• Abdominal Mass

  The patient subsequently developed a cutaneous lower abdominal mass that was diagnosed as an osteosarcoma. Meanwhile, the petrous apex tumor continued to grow despite treatment until the patient died from the burden of disease. [ncbi.nlm.nih.gov]

• Progressive Hearing Loss

  We report an interesting and rare case of aggressive osteoblastoma, with progressive hearing loss and facial palsy, involving the mastoid process of temporal bone and middle ear along with the description of cyto-morphological features. [ncbi.nlm.nih.gov]

  When it arises from temporal bone and middle it may cause progressive hearing loss. [ijpmonline.org]

• Subcutaneous Mass

  Although clinical presentation can vary depending on location, cranial osteoblastoma usually presents as a painful, non-mobile, subcutaneous mass or swelling. [ncbi.nlm.nih.gov]

• Photophobia

  A 31 year old man came to our attention with a 7 month history of diplopia, photophobia, frontal headhaches and progressive exophthalmos with proptosis of the left eye. [ncbi.nlm.nih.gov]

• Diplopia

  A 31 year old man came to our attention with a 7 month history of diplopia, photophobia, frontal headhaches and progressive exophthalmos with proptosis of the left eye. [ncbi.nlm.nih.gov]

• Visual Impairment

  OB exert local mass effects and accordingly, patients may present with spinal cord compression, radiculopathy, visual impairment and additional neurological deficits, stiffness and reduced joint motion ranges, among others. [symptoma.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]

• Neck Pain

  Even though the 18-month follow-up is still a very short interval in our case, the subject's neck pain has resolved completely and there has been no sign of tumor recurrence in the recently taken imaging. [ncbi.nlm.nih.gov]

• Ankle Pain

  We report a young male, presenting as chronic ankle pain, with a radiolucent lesion with a thick periosteal shell in the body of the talus. Analysis of clinical, radiological and histological findings confirmed the diagnosis of osteoblastoma. [ncbi.nlm.nih.gov]

  Vasu Pai MS, D[Orth], National board [Orth], FICMR, FRACS, MCh[Orth] 1, Vishal Pai, M.B., Chb 2 The Foot & Ankle Journal 1 (6): 5 ISSN 1941-6806 doi: 10.3827/faoj.2008.0106.0005 Case History An 8 year old boy presents with history of ankle pain for 4 [faoj.org]

• 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]

• Facial Swelling

  A 7-year-old male patient visited our department with chief complaints of left facial swelling and pain. A panoramic radiograph showed a homogeneous radio-opaque expansile lesion in the left maxilla. [ncbi.nlm.nih.gov]

  Pain and swelling of the affected area are typical characteristics of benign osteoblastoma of facial bones. However, the lesion can be discovered in routine clinical examination while not presenting any signs or causing any symptoms (10,11). [arquivosdeorl.org.br]

• Neck Mass

  We present the first known case of osteoblastoma arising in the hyoid bone, in a patient who presented with a neck mass and dysphagia. [ncbi.nlm.nih.gov]

• Claustrophobia

  The lengthy duration of an MRI examination and a history of claustrophobia in some patients are limiting the use of MRI. [en.wikipedia.org]

• Meningism

  To our best knowledge, this is possibly the first case of primary osteoblastoma arising from meninges. Meningeal osteocartilaginous tumors are rare, with obscure histogenesis. [ncbi.nlm.nih.gov]

  During surgery, it was observed that the tumor was compressing the meninges of the middle fossa, and in some locations it was strongly adhered to the meninges, which determined tearing of the same during resection. [arquivosdeorl.org.br]

  In the postoperative period the patient developed a transient cerebrospinal fluid (CSF) fistula and a meningitis, responsive to lumbar drainage and antibiotic therapy. He was discharged two weeks after surgical treatment without neurologic deficits. [scielo.br]

• Cranial Nerve Involvement

  Clinical symptoms are non-specific and cranial nerve involvement is uncommon. The cytomorphological features of osteoblastoma are not very well defined and the experience is limited to only few reports. [ncbi.nlm.nih.gov]

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]

The first route of treatment in Osteoblastoma is via medical means. Although necessary, radiation therapy (or chemotherapy) is controversial in the treatment of osteoblastoma. [en.wikipedia.org]

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]

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

Still, OB patients generally have a good prognosis and most of them are cured by means of a complete surgical resection of the neoplasm. [symptoma.com]

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]

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]

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]

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]

Introduction Aggressive benign osteoblastic tumor of bone "big brother" of osteoid osteoma ( nidus > 2cm ) Epidemiology incidence relatively rare less common than osteoid osteoma demographics males > females (2:1) majority of patients 10-30 years of age [orthobullets.com]

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

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]

Pathophysiology, evaluation, and treatment. J Bone Joint Surg Am 2005;87(8):1848-64. 27. Riddle ND, Bui MM. Fibrous dysplasia. Arch Pathol Lab Med 2013;137(1):134-8. 28. Feller L, Neil H Wood, Razia AG Khammissa, et al. [jebmh.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.