Medulloblastoma, SHH-activated
Updates to Article Attributes
Medulloblastoma - sonic hedgehog (SHH) subgroup tumours are malignant tumours of the central nervous system. They are the second most common medulloblastoma subgroup (after group 4) and are approximately as common as group 3. They are found most commonly in adults and infants, but infrequently in children. Although they can arise from the vermis of the cerebellum, as is typical for group 3 and 4, they most frequently are located laterally within the cerebellar hemispheres.
Epidemiology
SHH subgroup tumours account for approximately 27% of all medulloblastomas, and have, unlike group 3 and 4, no particular predilection for males, with ~1:1 male to female ratio 1-2.
They are most frequently encountered in adults (>16 year) and infants (<4 years) but are uncommon in children 1-2.
Pathology
SHH medulloblastomas can demonstrate various histologies, with classic, large cell/anaplastic and desmoplastic/nodular/medulloblastoma with extensive nodularity (MBEN) all encountered 2.
Importantly almost all desmoplastic/nodular/medulloblastoma with extensive nodularity (MBEN) tumours are SHH subtype 2.
Radiographic features
The radiographic features of SHH subgroup tumours are variable depending on to a degree on histological subtype.
Content pending
The pleasureWhen they are of an ever-improving collaborative resource is that sometimes you find yourselfclassic or large cell / anaplastic histology and located in the middlemidline they are essentially indistinguishable from group 3 and group 4 tumours 3.
The desmoplastic/nodular/medulloblastoma with extensive nodularity (MBEN) tumours on the other hand tend to be in the lateral parts of a construction zonethe cerebellar hemispheres 3.
Until we finish,For more details on radiographic features please refer to the existing maingeneral article on medulloblastomas.
Treatment and prognosis
Surgery is the first line of therapy (as is the case in all subgroups) with the aim being histological proof, molecular subtyping and maximal tumour resection, with adjuvant therapy depending on an overall risk profile (see general article on medulloblastoma) 2.
The incidence of CNS metastatic disease in the SHH subgroup at diagnosis is relatively common in infants (17%) and children (22%) but is uncommon in adults 1.
SHH tumours have intermediate prognosis compared to other subtypes of medulloblastoma, better than group 3 tumours, but significant worse than WNT subtypes 1:
- 77% 10-year overall survival of in infants
- 51% 10-year overall survival of in children
- 35% 10-year overall survival of in adults
Prognosis is also influenced by histological subtype.
-<p><strong>Medulloblastoma - sonic hedgehog (SHH) subgroup tumours </strong>are malignant tumours of the central nervous system. They are the second most common <a href="/articles/medulloblastoma">medulloblastoma</a> subgroup (after group 4) and are approximately as common as group 3. They are found most commonly in adults and infants, but infrequently in children. Although they can arise from the vermis of the cerebellum, as is typical for group 3 and 4, they most frequently are located laterally within the cerebellar hemispheres. </p><h4>Epidemiology</h4><p>SHH subgroup tumours account for approximately 27% of all <a href="/articles/medulloblastoma">medulloblastomas</a>, and have, unlike group 3 and 4, no particular predilection for males, with ~1:1 male to female ratio <sup>1</sup>. </p><p>They are most frequently encountered in adults (>16 year) and infants (<4 years) but are uncommon in children <sup>1</sup>. </p><p> </p><p><em>Content pending</em></p><p><em>The pleasure of an ever-improving collaborative resource is that sometimes you find yourself in the middle of a construction zone. </em></p><p><em>Until we finish, please refer to the existing main article <a href="/articles/medulloblastoma">medulloblastoma</a>. </em></p>- +<p><strong>Medulloblastoma - sonic hedgehog (SHH) subgroup tumours </strong>are malignant tumours of the central nervous system. They are the second most common <a href="/articles/medulloblastoma">medulloblastoma</a> subgroup (after group 4) and are approximately as common as group 3. They are found most commonly in adults and infants, but infrequently in children. Although they can arise from the vermis of the cerebellum, as is typical for group 3 and 4, they most frequently are located laterally within the cerebellar hemispheres. </p><h4>Epidemiology</h4><p>SHH subgroup tumours account for approximately 27% of all <a href="/articles/medulloblastoma">medulloblastomas</a>, and have, unlike group 3 and 4, no particular predilection for males, with ~1:1 male to female ratio <sup>1-2</sup>. </p><p>They are most frequently encountered in adults (>16 year) and infants (<4 years) but are uncommon in children <sup>1-2</sup>. </p><h4>Pathology</h4><p>SHH medulloblastomas can demonstrate various histologies, with classic, large cell/anaplastic and desmoplastic/nodular/medulloblastoma with extensive nodularity (MBEN) all encountered <sup>2</sup>. </p><p>Importantly almost all desmoplastic/nodular/medulloblastoma with extensive nodularity (MBEN) tumours are SHH subtype <sup>2</sup>. </p><h4>Radiographic features</h4><p>The radiographic features of SHH subgroup tumours are variable depending on to a degree on histological subtype. </p><p>When they are of classic or large cell / anaplastic histology and located in the midline they are essentially indistinguishable from group 3 and group 4 tumours <sup>3</sup>. </p><p>The desmoplastic/nodular/medulloblastoma with extensive nodularity (MBEN) tumours on the other hand tend to be in the lateral parts of the cerebellar hemispheres <sup>3</sup>. </p><p>For more details on radiographic features please refer to the general article on <a href="/articles/medulloblastoma">medulloblastomas</a>. </p><h4>Treatment and prognosis</h4><p>Surgery is the first line of therapy (as is the case in all subgroups) with the aim being histological proof, molecular subtyping and maximal tumour resection, with adjuvant therapy depending on an overall risk profile (see general article on <a href="/articles/medulloblastoma">medulloblastoma</a>) <sup>2</sup>. </p><p>The incidence of CNS metastatic disease in the SHH subgroup at diagnosis is relatively common in infants (17%) and children (22%) but is uncommon in adults <sup>1</sup>. </p><p>SHH tumours have intermediate prognosis compared to other subtypes of medulloblastoma, better than group 3 tumours, but significant worse than WNT subtypes <sup>1</sup>:</p><ul>
- +<li>77% 10-year overall survival of in infants</li>
- +<li>51% 10-year overall survival of in children</li>
- +<li>35% 10-year overall survival of in adults</li>
- +</ul><p>Prognosis is also influenced by histological subtype. </p>
References changed:
- 1. Kool M, Korshunov A, Remke M et al. Molecular Subgroups of Medulloblastoma: An International Meta-Analysis of Transcriptome, Genetic Aberrations, and Clinical Data of WNT, SHH, Group 3, and Group 4 Medulloblastomas. Acta Neuropathol. 2012;123(4):473-84. <a href="https://doi.org/10.1007/s00401-012-0958-8">doi:10.1007/s00401-012-0958-8</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/22358457">Pubmed</a>
- 2. DeSouza R, Jones B, Lowis S, Kurian K. Pediatric Medulloblastoma - Update on Molecular Classification Driving Targeted Therapies. Front Oncol. 2014;4:176. <a href="https://doi.org/10.3389/fonc.2014.00176">doi:10.3389/fonc.2014.00176</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/25101241">Pubmed</a>
- 3. Perreault S, Ramaswamy V, Achrol A et al. MRI Surrogates for Molecular Subgroups of Medulloblastoma. AJNR Am J Neuroradiol. 2014;35(7):1263-9. <a href="https://doi.org/10.3174/ajnr.A3990">doi:10.3174/ajnr.A3990</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/24831600">Pubmed</a>
Systems changed:
- Central Nervous System
Image 2 MRI (T2) ( create )
Image 4 MRI (DWI) ( create )
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