Unicameral bone cyst: Difference between revisions

	WikiDoc Resources for Unicameral bone cyst
Articles
Most recent articles on Unicameral bone cyst Most cited articles on Unicameral bone cyst Review articles on Unicameral bone cyst Articles on Unicameral bone cyst in N Eng J Med, Lancet, BMJ
Media
Powerpoint slides on Unicameral bone cyst Images of Unicameral bone cyst Photos of Unicameral bone cyst Podcasts & MP3s on Unicameral bone cyst Videos on Unicameral bone cyst
Evidence Based Medicine
Cochrane Collaboration on Unicameral bone cyst Bandolier on Unicameral bone cyst TRIP on Unicameral bone cyst
Clinical Trials
Ongoing Trials on Unicameral bone cyst at Clinical Trials.gov Trial results on Unicameral bone cyst Clinical Trials on Unicameral bone cyst at Google
Guidelines / Policies / Govt
US National Guidelines Clearinghouse on Unicameral bone cyst NICE Guidance on Unicameral bone cyst NHS PRODIGY Guidance FDA on Unicameral bone cyst CDC on Unicameral bone cyst
Books
Books on Unicameral bone cyst
News
Unicameral bone cyst in the news Be alerted to news on Unicameral bone cyst News trends on Unicameral bone cyst
Commentary
Blogs on Unicameral bone cyst
Definitions
Definitions of Unicameral bone cyst
Patient Resources / Community
Patient resources on Unicameral bone cyst Discussion groups on Unicameral bone cyst Patient Handouts on Unicameral bone cyst Directions to Hospitals Treating Unicameral bone cyst Risk calculators and risk factors for Unicameral bone cyst
Healthcare Provider Resources
Symptoms of Unicameral bone cyst Causes & Risk Factors for Unicameral bone cyst Diagnostic studies for Unicameral bone cyst Treatment of Unicameral bone cyst
Continuing Medical Education (CME)
CME Programs on Unicameral bone cyst
International
Unicameral bone cyst en Espanol Unicameral bone cyst en Francais
Business
Unicameral bone cyst in the Marketplace Patents on Unicameral bone cyst
Experimental / Informatics
List of terms related to Unicameral bone cyst

← Older edit Newer edit →

VisualWikitext

Revision as of 22:19, 18 January 2019

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Rohan A. Bhimani, M.B.B.S., D.N.B., M.Ch.[2]

Synonyms and keywords:

Overview

Historical Perspective

In mediveal times, Lagier et al identified a unicameral bonce cyst in the femur from the remains of a child.^[1]
In 1891, Virchow reported it as “cystic structures” that resulted due to anomalies in the local circulation.^[2]
In 1942, Jaffe and Lichenstein later recognized it as a distinct entity.^[3]

Classification

Unicameral bone cyst can be classified based on imaging findings.

Enneking (MSTS) Staging System

The Enneking surgical staging system (also known as the MSTS system) for benign musculoskeletal tumors based on radiographic characteristics of the tumor host margin.^[4]
It is widely accepted and routinely used classification.

Stages	Description

1	Latent: Well demarcated borders
2	Active: Indistinct borders
3	Aggressive: Indistinct borders

Pathophysiology

The exact pathogenesis of unicameral bone cyst is not fully understood.
Various theories have been proposed concerning the pathogenesis of unicameral bone cyst:
- Blockage in the venous drainage is the most favored mechanism which occurs in a rapidly growing and remodeling portion of cancellous bone.
- Increased internal pressure of involved bone as compared to normal pressure of bone marrow.^[5]
- Lower partial pressure of oxygen of cyst fluid than arterial or venous blood suggesting a venous obstruction.^[6]
- Increased levels of lysosomal enzymes in the cyst than serum. Enzymes include prostaglandins, interleukin 1β, nitrate and nitrites levels, proteolytic enzymes, tumor necrosis factor ⍺ and interleukins 1β and 6.^[7]
Unicameral bone cyst typically occur in the metaphysis adjacent to the physis of the long bones.
The bones often involved are proximal femur, distal tibia, ilium, calcaneus, and occasionally metacarpals, phalanges, or distal radius.

Genetics

Unicameral bone cyst may have association with genetic abnormalities on chromosome 4, 6, 8, 16, 21, and both chromosomes 12.
Translocation t (16; 20) (p11.2; q13) has been found in cases with unicameral bone cyst.

Causes

There are no established causes for unicameral bone cyst.

Differentiating Unicameral Bone Cyst from Other Diseases

Unicameral bone cyst must be differentiated from following bone disorders:

Disease	Bubbly lytic lesion on x-ray	Lakes of Blood on histology	Diagnosis	Treatment is curretage and bone grafting
Unicameral bone cyst	+	-	Radiology and biopsy	-
Aneurysmal bone cyst	+	+	Radiology and biopsy	+
Non ossifying fibroma	+	-	Radiology and biopsy	-
Giant cell tumor	-	-	Radiology and Biopsy	+
Chondroblastoma	-	-	Biopsy	+
Chondromyxoid Fibroma	-	-	Radiology and biopsy	+
Osteoblastoma	-	-	Radiology and biopsy	+
Telangiectatic osteosarcoma	-	+	Radiology and biopsy	-

Epidemiology and Demographics

Unicameral bone cyst constitute approximately 3% of all bone tumors.
Adolescents and children are most affected by unicameral bone cyst.^[8]
The age distribution of unicameral bone cyst is between 5-15 years.^[9]
The mean age of the patients with unicameral bone cyst is 9 years.
Men are more commonly affected than women, with a 2:1 ratio.^[10]
There is no racial predilection to chondroblastoma.

Risk Factors

There are no established risk factors for unicameral bone cyst.

Screening

There is insufficient evidence to recommend routine screening for unicameral bone cyst.

Natural History, Complications, and Prognosis

Common complications of unicameral bone cyst (UBC) include:
- Pathological fracture
- Premature epiphyseal closure
  - Limb-length discrepancy
  - Angular deformity
- Malignant transformation.
Prognosis is generally excellent for Unicameral bone cyst.
- As a patient approaches skeletal maturity, a unicameral bone cyst will often decrease in size and may heal after growth is complete.
- Fracture healing usually does not lead to cyst resolution.
- It requires close follow up while in active phase due to recurrence and risk of fracture or growth arrest.

Diagnosis

Diagnostic Study of Choice

The diagnosis of [disease name] is made when at least [number] of the following [number] diagnostic criteria are met: [criterion 1], [criterion 2], [criterion 3], and [criterion 4].

OR

The diagnosis of [disease name] is based on the [criteria name] criteria, which include [criterion 1], [criterion 2], and [criterion 3].

OR

The diagnosis of [disease name] is based on the [definition name] definition, which includes [criterion 1], [criterion 2], and [criterion 3].

OR

There are no established criteria for the diagnosis of [disease name].

History and Symptoms

The majority of patients with [disease name] are asymptomatic.

OR

The hallmark of [disease name] is [finding]. A positive history of [finding 1] and [finding 2] is suggestive of [disease name]. The most common symptoms of [disease name] include [symptom 1], [symptom 2], and [symptom 3]. Common symptoms of [disease] include [symptom 1], [symptom 2], and [symptom 3]. Less common symptoms of [disease name] include [symptom 1], [symptom 2], and [symptom 3].

Physical Examination

Patients with [disease name] usually appear [general appearance]. Physical examination of patients with [disease name] is usually remarkable for [finding 1], [finding 2], and [finding 3].

OR

Common physical examination findings of [disease name] include [finding 1], [finding 2], and [finding 3].

OR

The presence of [finding(s)] on physical examination is diagnostic of [disease name].

OR

The presence of [finding(s)] on physical examination is highly suggestive of [disease name].

Laboratory Findings

An elevated/reduced concentration of serum/blood/urinary/CSF/other [lab test] is diagnostic of [disease name].

OR

Laboratory findings consistent with the diagnosis of [disease name] include [abnormal test 1], [abnormal test 2], and [abnormal test 3].

OR

[Test] is usually normal among patients with [disease name].

OR

Some patients with [disease name] may have elevated/reduced concentration of [test], which is usually suggestive of [progression/complication].

OR

There are no diagnostic laboratory findings associated with [disease name].

Electrocardiogram

There are no ECG findings associated with [disease name].

OR

An ECG may be helpful in the diagnosis of [disease name]. Findings on an ECG suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].

X-ray

There are no x-ray findings associated with [disease name].

OR

An x-ray may be helpful in the diagnosis of [disease name]. Findings on an x-ray suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].

OR

There are no x-ray findings associated with [disease name]. However, an x-ray may be helpful in the diagnosis of complications of [disease name], which include [complication 1], [complication 2], and [complication 3].

Echocardiography or Ultrasound

There are no echocardiography/ultrasound findings associated with [disease name].

OR

Echocardiography/ultrasound may be helpful in the diagnosis of [disease name]. Findings on an echocardiography/ultrasound suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].

OR

There are no echocardiography/ultrasound findings associated with [disease name]. However, an echocardiography/ultrasound may be helpful in the diagnosis of complications of [disease name], which include [complication 1], [complication 2], and [complication 3].

CT scan

There are no CT scan findings associated with [disease name].

OR

[Location] CT scan may be helpful in the diagnosis of [disease name]. Findings on CT scan suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].

OR

There are no CT scan findings associated with [disease name]. However, a CT scan may be helpful in the diagnosis of complications of [disease name], which include [complication 1], [complication 2], and [complication 3].

MRI

There are no MRI findings associated with [disease name].

OR

[Location] MRI may be helpful in the diagnosis of [disease name]. Findings on MRI suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].

OR

There are no MRI findings associated with [disease name]. However, a MRI may be helpful in the diagnosis of complications of [disease name], which include [complication 1], [complication 2], and [complication 3].

Other Imaging Findings

There are no other imaging findings associated with [disease name].

OR

[Imaging modality] may be helpful in the diagnosis of [disease name]. Findings on an [imaging modality] suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].

Other Diagnostic Studies

There are no other diagnostic studies associated with [disease name].

OR

[Diagnostic study] may be helpful in the diagnosis of [disease name]. Findings suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].

OR

Other diagnostic studies for [disease name] include [diagnostic study 1], which demonstrates [finding 1], [finding 2], and [finding 3], and [diagnostic study 2], which demonstrates [finding 1], [finding 2], and [finding 3].

Treatment

Medical Therapy

There is no treatment for [disease name]; the mainstay of therapy is supportive care.

OR

Supportive therapy for [disease name] includes [therapy 1], [therapy 2], and [therapy 3].

OR

The majority of cases of [disease name] are self-limited and require only supportive care.

OR

[Disease name] is a medical emergency and requires prompt treatment.

OR

The mainstay of treatment for [disease name] is [therapy].

OR The optimal therapy for [malignancy name] depends on the stage at diagnosis.

OR

[Therapy] is recommended among all patients who develop [disease name].

OR

Pharmacologic medical therapy is recommended among patients with [disease subclass 1], [disease subclass 2], and [disease subclass 3].

OR

Pharmacologic medical therapies for [disease name] include (either) [therapy 1], [therapy 2], and/or [therapy 3].

OR

Empiric therapy for [disease name] depends on [disease factor 1] and [disease factor 2].

OR

Patients with [disease subclass 1] are treated with [therapy 1], whereas patients with [disease subclass 2] are treated with [therapy 2].

Surgery

Surgical intervention is not recommended for the management of [disease name].

OR

Surgery is not the first-line treatment option for patients with [disease name]. Surgery is usually reserved for patients with either [indication 1], [indication 2], and [indication 3]

OR

The mainstay of treatment for [disease name] is medical therapy. Surgery is usually reserved for patients with either [indication 1], [indication 2], and/or [indication 3].

OR

The feasibility of surgery depends on the stage of [malignancy] at diagnosis.

OR

Surgery is the mainstay of treatment for [disease or malignancy].

Primary Prevention

There are no established measures for the primary prevention of [disease name].

OR

There are no available vaccines against [disease name].

OR

Effective measures for the primary prevention of [disease name] include [measure1], [measure2], and [measure3].

OR

[Vaccine name] vaccine is recommended for [patient population] to prevent [disease name]. Other primary prevention strategies include [strategy 1], [strategy 2], and [strategy 3].

Secondary Prevention

There are no established measures for the secondary prevention of [disease name].

OR

Effective measures for the secondary prevention of [disease name] include [strategy 1], [strategy 2], and [strategy 3].

References

↑ Lagier R, Kramar C, Baud CA (1987). "Femoral unicameral bone cyst in a medieval child. Radiological and pathological study". Pediatr Radiol. 17 (6): 498–500. PMID 3317251.
↑ Wilkins RM (2000). "Unicameral bone cysts". J Am Acad Orthop Surg. 8 (4): 217–24. PMID 10951110.
↑ Jaffe HL, Lichtenstein L. Solitary unicameral bone cyst with emphasis on the roentgen picture, the pathologic appearance and the pathogenesis. Arch Surg. 1942. 44:1004-25.
↑ Jawad MU, Scully SP (2010). "In brief: classifications in brief: enneking classification: benign and malignant tumors of the musculoskeletal system". Clin Orthop Relat Res. 468 (7): 2000–2. doi:10.1007/s11999-010-1315-7. PMC 2882012. PMID 20333492.
↑ Chigira M., Maehara S., Arita S., Udagawa E. The aetiology and treatment of simple bone cysts. Bone & Joint Journal. 1983;65(5):633–637.
↑ Chigira M., Maehara S., Arita S., Udagawa E. The aetiology and treatment of simple bone cysts. Bone & Joint Journal. 1983;65(5):633–637.
↑ Komiya S, Inoue A (2000). "Development of a solitary bone cyst--a report of a case suggesting its pathogenesis". Arch Orthop Trauma Surg. 120 (7–8): 455–7. PMID 10968539.
↑ Pretell-Mazzini J, Murphy RF, Kushare I, Dormans JP (2014). "Unicameral bone cysts: general characteristics and management controversies". J Am Acad Orthop Surg. 22 (5): 295–303. doi:10.5435/JAAOS-22-05-295. PMID 24788445.
↑ Biermann JS (2002). "Common benign lesions of bone in children and adolescents". J Pediatr Orthop. 22 (2): 268–73. PMID 11856945.
↑ Boseker EH, Bickel WH, Dahlin DC (1968). "A clinicopathologic study of simple unicameral bone cysts". Surg Gynecol Obstet. 127 (3): 550–60. PMID 4874360.

Template:WikiDoc Sources

[pmid3317251-1] Lagier R, Kramar C, Baud CA (1987). "Femoral unicameral bone cyst in a medieval child. Radiological and pathological study". Pediatr Radiol. 17 (6): 498–500. PMID 3317251.

[pmid10951110-2] Wilkins RM (2000). "Unicameral bone cysts". J Am Acad Orthop Surg. 8 (4): 217–24. PMID 10951110.

[3] Jaffe HL, Lichtenstein L. Solitary unicameral bone cyst with emphasis on the roentgen picture, the pathologic appearance and the pathogenesis. Arch Surg. 1942. 44:1004-25.

[pmid20333492-4] Jawad MU, Scully SP (2010). "In brief: classifications in brief: enneking classification: benign and malignant tumors of the musculoskeletal system". Clin Orthop Relat Res. 468 (7): 2000–2. doi:10.1007/s11999-010-1315-7. PMC 2882012. PMID 20333492.

[5] Chigira M., Maehara S., Arita S., Udagawa E. The aetiology and treatment of simple bone cysts. Bone & Joint Journal. 1983;65(5):633–637.

[6] Chigira M., Maehara S., Arita S., Udagawa E. The aetiology and treatment of simple bone cysts. Bone & Joint Journal. 1983;65(5):633–637.

[pmid10968539-7] Komiya S, Inoue A (2000). "Development of a solitary bone cyst--a report of a case suggesting its pathogenesis". Arch Orthop Trauma Surg. 120 (7–8): 455–7. PMID 10968539.

[pmid24788445-8] Pretell-Mazzini J, Murphy RF, Kushare I, Dormans JP (2014). "Unicameral bone cysts: general characteristics and management controversies". J Am Acad Orthop Surg. 22 (5): 295–303. doi:10.5435/JAAOS-22-05-295. PMID 24788445.

[pmid11856945-9] Biermann JS (2002). "Common benign lesions of bone in children and adolescents". J Pediatr Orthop. 22 (2): 268–73. PMID 11856945.

[pmid4874360-10] Boseker EH, Bickel WH, Dahlin DC (1968). "A clinicopathologic study of simple unicameral bone cysts". Surg Gynecol Obstet. 127 (3): 550–60. PMID 4874360.

[1]

[2]

[3]

[4]

[5]

[6]

[7]

[8]

[9]

[10]

@@ Line 40: / Line 40: @@
 *Various theories have been proposed concerning the pathogenesis of unicameral bone cyst:
 **Blockage in the venous drainage is the most favored mechanism which occurs in a rapidly growing and remodeling portion of cancellous bone.
-**
+**Increased internal pressure of involved bone as compared to normal pressure of bone marrow.<ref>Chigira M., Maehara S., Arita S., Udagawa E. The aetiology and treatment of simple bone cysts. Bone & Joint Journal. 1983;65(5):633–637.</ref>
+**Lower partial pressure of oxygen of cyst fluid than arterial or venous blood suggesting a venous obstruction.<ref>Chigira M., Maehara S., Arita S., Udagawa E. The aetiology and treatment of simple bone cysts. Bone & Joint Journal. 1983;65(5):633–637.</ref>
+**Increased levels of lysosomal enzymes in the cyst than serum. Enzymes include prostaglandins, interleukin 1β, nitrate and nitrites levels, proteolytic enzymes, tumor necrosis factor ⍺ and interleukins 1β and 6.<ref name="pmid10968539">{{cite journal| author=Komiya S, Inoue A| title=Development of a solitary bone cyst--a report of a case suggesting its pathogenesis. | journal=Arch Orthop Trauma Surg | year= 2000 | volume= 120 | issue= 7-8 | pages= 455-7 | pmid=10968539 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=10968539  }} </ref>
+*Unicameral bone cyst typically occur in the metaphysis adjacent to the physis of the long bones.
+*The bones often involved are proximal femur, distal tibia, ilium, calcaneus, and occasionally metacarpals, phalanges, or distal radius.
+===Genetics===
+*Unicameral bone cyst may have association with genetic abnormalities on chromosome 4, 6, 8, 16, 21, and both chromosomes 12.
+*Translocation t (16; 20) (p11.2; q13) has been found in cases with unicameral bone cyst.
 ==Causes==
-Disease name] may be caused by [cause1], [cause2], or [cause3].
+There are no established causes for unicameral bone cyst.
-OR
-Common causes of [disease] include [cause1], [cause2], and [cause3].
-OR
+==Differentiating Unicameral Bone Cyst from Other Diseases==
+Unicameral bone cyst must be differentiated from following bone disorders:
+{|
+! align="center" style="background:#4479BA; color: #FFFFFF;" + |Disease
+! align="center" style="background:#4479BA; color: #FFFFFF;" + |'''Bubbly lytic lesion on x-ray'''
+! align="center" style="background:#4479BA; color: #FFFFFF;" + |'''Lakes of Blood on histology'''
+! align="center" style="background:#4479BA; color: #FFFFFF;" + |Diagnosis
+! align="center" style="background:#4479BA; color: #FFFFFF;" + |Treatment is curretage and bone grafting
+|-
+! align="center" style="background:#DCDCDC;" + |Unicameral bone cyst
+| align="center" style="background:#F5F5F5;" + | +
+| align="center" style="background:#F5F5F5;" + | -
+| align="center" style="background:#F5F5F5;" + |[[Radiology]] and [[biopsy]]
+| align="center" style="background:#F5F5F5;" + | -
+|-
+! align="center" style="background:#DCDCDC;" + |Aneurysmal bone cyst
+| align="center" style="background:#F5F5F5;" + | +
+| align="center" style="background:#F5F5F5;" + | +
+| align="center" style="background:#F5F5F5;" + |[[Radiology]] and [[biopsy]]
+| align="center" style="background:#F5F5F5;" + | +
+|-
+! align="center" style="background:#DCDCDC;" + |Non ossifying fibroma
+| align="center" style="background:#F5F5F5;" + | +
+| align="center" style="background:#F5F5F5;" + | -
+| align="center" style="background:#F5F5F5;" + |[[Radiology]] and [[biopsy]]
+| align="center" style="background:#F5F5F5;" + | -
+|-
+! align="center" style="background:#DCDCDC;" + |Giant cell tumor
+| align="center" style="background:#F5F5F5;" + | -
+| align="center" style="background:#F5F5F5;" + | -
+| align="center" style="background:#F5F5F5;" + |[[Radiology]] and [[Biopsy]]
+| align="center" style="background:#F5F5F5;" + | +
+|-
+! align="center" style="background:#DCDCDC;" + |Chondroblastoma
+| align="center" style="background:#F5F5F5;" + | -
+| align="center" style="background:#F5F5F5;" + | -
+| align="center" style="background:#F5F5F5;" + |[[Biopsy]]
+| align="center" style="background:#F5F5F5;" + | +
+|-
+! align="center" style="background:#DCDCDC;" + |Chondromyxoid Fibroma
+| align="center" style="background:#F5F5F5;" + | -
+| align="center" style="background:#F5F5F5;" + | -
+| align="center" style="background:#F5F5F5;" + |[[Radiology]] and [[biopsy]]
+| align="center" style="background:#F5F5F5;" + | +
+|-
+! align="center" style="background:#DCDCDC;" + |Osteoblastoma
+| align="center" style="background:#F5F5F5;" + | -
+| align="center" style="background:#F5F5F5;" + | -
+| align="center" style="background:#F5F5F5;" + |[[Radiology]] and [[biopsy]]
+| align="center" style="background:#F5F5F5;" + | +
+|-
+! align="center" style="background:#DCDCDC;" + |Telangiectatic osteosarcoma
+| align="center" style="background:#F5F5F5;" + | -
+| align="center" style="background:#F5F5F5;" + | +
+| align="center" style="background:#F5F5F5;" + |[[Radiology]] and [[biopsy]]
+| align="center" style="background:#F5F5F5;" + | -
+|}
-The most common cause of [disease name] is [cause 1]. Less common causes of [disease name] include [cause 2], [cause 3], and [cause 4].
-OR
-The cause of [disease name] has not been identified. To review risk factors for the development of [disease name], click [[Pericarditis causes#Overview|here]].
-==Differentiating ((Page name)) from Other Diseases==
-[Disease name] must be differentiated from other diseases that cause [clinical feature 1], [clinical feature 2], and [clinical feature 3], such as [differential dx1], [differential dx2], and [differential dx3].
-OR
-[Disease name] must be differentiated from [[differential dx1], [differential dx2], and [differential dx3].
 ==Epidemiology and Demographics==
-The incidence/prevalence of [disease name] is approximately [number range] per 100,000 individuals worldwide.
+*Unicameral bone cyst constitute approximately 3% of all bone tumors.
+*Adolescents and children are most affected by unicameral bone cyst.<ref name="pmid24788445">{{cite journal| author=Pretell-Mazzini J, Murphy RF, Kushare I, Dormans JP| title=Unicameral bone cysts: general characteristics and management controversies. | journal=J Am Acad Orthop Surg | year= 2014 | volume= 22 | issue= 5 | pages= 295-303 | pmid=24788445 | doi=10.5435/JAAOS-22-05-295 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=24788445  }} </ref>
-OR
+*The age distribution of unicameral bone cyst is between 5-15 years.<ref name="pmid11856945">{{cite journal| author=Biermann JS| title=Common benign lesions of bone in children and adolescents. | journal=J Pediatr Orthop | year= 2002 | volume= 22 | issue= 2 | pages= 268-73 | pmid=11856945 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=11856945  }} </ref>
+*The mean age of the patients with unicameral bone cyst is 9 years.
-In [year], the incidence/prevalence of [disease name] was estimated to be [number range] cases per 100,000 individuals worldwide.
+*Men are more commonly affected than women, with a 2:1 ratio.<ref name="pmid4874360">{{cite journal| author=Boseker EH, Bickel WH, Dahlin DC| title=A clinicopathologic study of simple unicameral bone cysts. | journal=Surg Gynecol Obstet | year= 1968 | volume= 127 | issue= 3 | pages= 550-60 | pmid=4874360 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=4874360  }} </ref>
+*There is no racial predilection to chondroblastoma.
-OR
-In [year], the incidence of [disease name] is approximately [number range] per 100,000 individuals with a case-fatality rate of [number range]%.
-Patients of all age groups may develop [disease name].
-OR
-The incidence of [disease name] increases with age; the median age at diagnosis is [#] years.
-OR
-[Disease name] commonly affects individuals younger than/older than [number of years] years of age.
-OR
-[Chronic disease name] is usually first diagnosed among [age group].
-OR
-[Acute disease name] commonly affects [age group].
-There is no racial predilection to [disease name].
-OR
-[Disease name] usually affects individuals of the [race 1] race. [Race 2] individuals are less likely to develop [disease name].
-[Disease name] affects men and women equally.
-OR
-[Gender 1] are more commonly affected by [disease name] than [gender 2]. The [gender 1] to [gender 2] ratio is approximately [number > 1] to 1.
-The majority of [disease name] cases are reported in [geographical region].
-OR
-[Disease name] is a common/rare disease that tends to affect [patient population 1] and [patient population 2].
 ==Risk Factors==
-There are no established risk factors for [disease name].
+There are no established risk factors for unicameral bone cyst.
-OR
-The most potent risk factor in the development of [disease name] is [risk factor 1]. Other risk factors include [risk factor 2], [risk factor 3], and [risk factor 4].
-OR
-Common risk factors in the development of [disease name] include [risk factor 1], [risk factor 2], [risk factor 3], and [risk factor 4].
-OR
-Common risk factors in the development of [disease name] may be occupational, environmental, genetic, and viral.
 ==Screening==
-There is insufficient evidence to recommend routine screening for [disease/malignancy].
+There is insufficient evidence to recommend routine screening for unicameral bone cyst.
-OR
-According to the [guideline name], screening for [disease name] is not recommended.
-OR
-According to the [guideline name], screening for [disease name] by [test 1] is recommended every [duration] among patients with [condition 1], [condition 2], and [condition 3].
 ==Natural History, Complications, and Prognosis==
-If left untreated, [#]% of patients with [disease name] may progress to develop [manifestation 1], [manifestation 2], and [manifestation 3].
+*Common complications of unicameral bone cyst (UBC) include:
+**Pathological fracture
-OR
+**Premature epiphyseal closure
+***Limb-length discrepancy
-Common complications of [disease name] include [complication 1], [complication 2], and [complication 3].
+***Angular deformity
+**Malignant transformation.
-OR
+*Prognosis is generally excellent for Unicameral bone cyst.
+**As a patient approaches skeletal maturity, a unicameral bone cyst will often decrease in size and may heal after growth is complete.
-Prognosis is generally excellent/good/poor, and the 1/5/10-year mortality/survival rate of patients with [disease name] is approximately [#]%.
+**Fracture healing usually does not lead to cyst resolution.
+**It requires close follow up while in active phase due to recurrence and risk of fracture or growth arrest.
 ==Diagnosis==