Orbital dermoid cyst
Updates to Article Attributes
Orbital dermoid cysts are congenital lesions representing closed sacs lined by an ectodermal epithelium and corresponding to the most common orbital tumour in children.
Epidemiology
content pendingThey correspond to ~2% of orbital tumours 5.
Clinical presentation
As they grow slowly, less than 25% of them are identified at birth and they usually manifest in the first decade of life. Clinical features include subcutaneous painless mass along the zygomaticofrontal and the frontoethmoidal sutures 1,3.
It is important to note that more than 80% occur in the upper outer quadrant or the lacrimal fossa (external angular dermoid) 1.
Pathology
Dermoid cysts are thought to occur as a developmental anomaly in which embryonic ectoderm is trapped in the closing neural tube between the 5th-6th weeks of gestation 1,3.
Dermoid cysts, like epidermoid cysts are lined by stratified squamous epithelium. Unlike epidermoid cysts however they also have epidermal appendages such as hair follicles, sweat and sebaceous glands. The latter is responsible for the secretion of sebum which imparts the characteristic appearance of these lesions on CT and MRI.
A common misconception is that dermoid cysts contain adipose tissue. This is not the case, as lipocytes are mesodermal in origin and dermoid cysts (by definition) are purely ectodermal. A dermoid cyst with adipose tissue would be a teratoma.
Radiographic features
content pendingThese lesions are usually extraconal, non-enhancing mass with smooth margins, cystic and/or solid components which are demonstrated on imaging by fat, fluid or soft tissue signal; occasionally calcifications may be present. Ruptured dermoids may show adjacent inflammatory changes (see case 2).
Treatment and prognosis
- content pending
Differential diagnosis
- orbital epidermoid cyst
- orbital teratoma
- orbital dermolipoma
-<p><strong>Orbital dermoid cysts</strong> are congenital lesions representing closed sacs lined by an ectodermal epithelium and corresponding to the most common orbital tumour in children. </p><h4>Epidemiology</h4><ul><li><em>content pending </em></li></ul><h4>Clinical presentation</h4><p>As they grow slowly, less than 25% of them are identified at birth and <br>they usually manifest in the first decade of life. Clinical features include subcutaneous painless mass along the zygomaticofrontal and the frontoethmoidal sutures <sup>1,3</sup>.</p><p>It is important to note that more than 80% occur in the upper outer quadrant or the lacrimal fossa (external angular dermoid) <sup>1</sup>.</p><h4>Pathology </h4><p>Dermoid cysts are thought to occur as a developmental anomaly in which embryonic ectoderm is trapped in the closing neural tube between the 5th-6th weeks of gestation <sup>1,3</sup>. </p><p>Dermoid cysts, like epidermoid cysts are lined by stratified squamous epithelium. Unlike epidermoid cysts however they also have epidermal appendages such as hair follicles, sweat and sebaceous glands. The latter is responsible for the secretion of sebum which imparts the characteristic appearance of these lesions on CT and MRI.</p><p>A common misconception is that dermoid cysts contain adipose tissue. This is not the case, as lipocytes are mesodermal in origin and dermoid cysts (by definition) are purely ectodermal. A dermoid cyst with adipose tissue would be a teratoma. </p><h4>Radiographic features</h4><ul><li><em>content pending </em></li></ul><h4>Treatment and prognosis</h4><ul><li><em>content pending </em></li></ul><h4>Differential diagnosis</h4><ul>- +<p><strong>Orbital dermoid cysts</strong> are congenital lesions representing closed sacs lined by an ectodermal epithelium and corresponding to the most common orbital tumour in children. </p><h4>Epidemiology</h4><p>They correspond to ~2% of orbital tumours <sup>5</sup>. </p><h4>Clinical presentation</h4><p>As they grow slowly, less than 25% of them are identified at birth and <br>they usually manifest in the first decade of life. Clinical features include subcutaneous painless mass along the zygomaticofrontal and the frontoethmoidal sutures <sup>1,3</sup>.</p><p>It is important to note that more than 80% occur in the upper outer quadrant or the lacrimal fossa (external angular dermoid) <sup>1</sup>.</p><h4>Pathology </h4><p>Dermoid cysts are thought to occur as a developmental anomaly in which embryonic ectoderm is trapped in the closing neural tube between the 5th-6th weeks of gestation <sup>1,3</sup>. </p><p>Dermoid cysts, like epidermoid cysts are lined by stratified squamous epithelium. Unlike epidermoid cysts however they also have epidermal appendages such as hair follicles, sweat and sebaceous glands. The latter is responsible for the secretion of sebum which imparts the characteristic appearance of these lesions on CT and MRI.</p><p>A common misconception is that dermoid cysts contain adipose tissue. This is not the case, as lipocytes are mesodermal in origin and dermoid cysts (by definition) are purely ectodermal. A dermoid cyst with adipose tissue would be a teratoma. </p><h4>Radiographic features</h4><p>These lesions are usually extraconal, non-enhancing mass with smooth margins, cystic and/or solid components which are demonstrated on imaging by fat, fluid or soft tissue signal; occasionally calcifications may be present. Ruptured dermoids may show adjacent inflammatory changes (see case 2). </p><h4>Treatment and prognosis</h4><ul><li><em>content pending </em></li></ul><h4>Differential diagnosis</h4><ul>
References changed:
- 4. Vashisht S, Ghai S, Hatimota P, Ghai S, Betharia S M. Cystic lesions of the orbit : A CT spectrum. Indian J Radiol Imaging [serial online] 2003 [cited 2015 Jun 26];13:139-44. Available from: http://www.ijri.org/text.asp?2003/13/2/139/28646
- 5. Kudo K, Tsutsumi S, Suga Y et-al. Orbital dermoid cyst with intratumoral inflammatory hemorrhage: case report. Neurol. Med. Chir. (Tokyo). 2008;48 (8): 359-62. <a href="http://www.ncbi.nlm.nih.gov/pubmed/18719327">Pubmed citation</a><span class="auto"></span>
Unable to process the form. Check for errors and try again.