Answer for BIR CoW 10 Oct 2021
Melorheostosis
Findings
MRI FINDINGS: T1/T2 linear hypointense periosteal reaction with intact cortex in upper right lateral aspect of shaft of tibia without diffusion restriction. T2/STIR hyperintensity noted within the lesion without diffusion restriction. PET FINDINGS: Periosteal reaction /intra cortical lesion with surrounding cortical thickening along the posterolateral aspect of right tibia with skip areas, there is central lucency / soft tissue and mild metabolic activity within the lesion. Features suggestive of sclerotic bone dysplasia (Melorheostosis)
Discussion
It is a rare condition with an estimated prevalence of 0.9 per million Affects both sexes equally The disease manifests during late childhood or early adulthood; however, it can occur at any age It is a unilateral disease of the peripheral skeleton, more commonly affecting the lower extremities with a diaphyseal predilection Melorheostosis rarely affects the axial skeleton . There are two major theories attempting to explain its origin. Murray and McCredie hypothesized that melorheostosis results from insult to segments of the neural crest during embryogenesis, resulting in segmental sensory lesions. Fryns hypothesized that melorheostosis results from post zygotic mutations in the mesenchyme. These mutations lead to variable and asymmetric involvement of the skeletal structures, and vascular and hamartomatous changes in the overlying soft tissues . Usually asymptomatic; however, various symptoms, including pain, limitation of movement, deformities, limb swelling, and limb length discrepancy may occur in growing children Melorheostosis may be associated with ossified and non-ossified soft tissue masses, usually surrounding the joints. The symptoms may arise due to impingement on nearby structures, either directly or through associated soft tissue masses. These masses are not necessarily a continuum of the disease lesions . Melorheostosis has been associated with various conditions, including neurofibromatosis, tuberous sclerosis, linear scleroderma, tricho-dento-osseous syndrome, rheumatoid arthritis, hypophosphatemic rickets, vascular malformations, and hemangioma . The disease may extend along the affected cortex in a proximal to distal pattern, resembling the pathognomonic “dripping candle wax” appearance Other radiologic appearances include osteoma, an osteopathia striata-like appearance, and myositis ossificans-like lesions without lamellae in soft tissues . CT show cortical thickening that might extend to the medulla, with a clear demarcation between the normal bone and the hyperostotic lesions .Additionally, clearly depict soft tissue abnormalities associated with the disease. MRI typically shows cortical hyperostosis of low signal intensity on all pulse sequences . Rarely, may show enhancing soft tissue masses that resemble aggressive neoplastic lesions PET typically show high uptake of the tracer on bone scintigraphy that crosses the adjacent joints
REFERENCES:
1. Vanhoenacker FM, De Beuckeleer LH, Van Hul W, et al. Sclerosing bone dysplasias: genetic and radioclinical features. Eur Radiol 2000;10:1423–1433. 2. Greenspan A. Sclerosing bone dysplasias: a targetsite approach. Skeletal Radiol 1991;20 3. de Vernejoul MC. Sclerosing bone disorders. Best Pract Res Clin Rheumatol 2008;22(1):71–83. 4. Van Hul W. Lessons from sclerosing bone dysplasias. Horm Res 2007;68(suppl 5):37–39. 5. Beighton P, Hamersma H. The orthopaedic implications of the sclerosing bone dysplasias. S Afr Med J 1980;58 6. Viot G, Lacombe D, David A, et al. Osteopathia striata cranial sclerosis: non-random X-inactivation suggestive of X-linked dominant inheritance. Am J Med Genet 2002;107(1):1–4. 7. Kinoshita A, Saito T, Tomita H, et al. Domainspecific mutations in TGFB1 result in CamuratiEngelmann disease. Nat Genet 2000;26(1) 8. Janssens K, Gershoni-Baruch R, Guañabens N, et al. Mutations in the gene encoding the latency-associated peptide of TGF-beta 1 cause Camurati-Engelmann disease. Nat Genet 2000;26(3)
Findings
MRI FINDINGS: T1/T2 linear hypointense periosteal reaction with intact cortex in upper right lateral aspect of shaft of tibia without diffusion restriction. T2/STIR hyperintensity noted within the lesion without diffusion restriction. PET FINDINGS: Periosteal reaction /intra cortical lesion with surrounding cortical thickening along the posterolateral aspect of right tibia with skip areas, there is central lucency / soft tissue and mild metabolic activity within the lesion. Features suggestive of sclerotic bone dysplasia (Melorheostosis)
Discussion
It is a rare condition with an estimated prevalence of 0.9 per million Affects both sexes equally The disease manifests during late childhood or early adulthood; however, it can occur at any age It is a unilateral disease of the peripheral skeleton, more commonly affecting the lower extremities with a diaphyseal predilection Melorheostosis rarely affects the axial skeleton . There are two major theories attempting to explain its origin. Murray and McCredie hypothesized that melorheostosis results from insult to segments of the neural crest during embryogenesis, resulting in segmental sensory lesions. Fryns hypothesized that melorheostosis results from post zygotic mutations in the mesenchyme. These mutations lead to variable and asymmetric involvement of the skeletal structures, and vascular and hamartomatous changes in the overlying soft tissues . Usually asymptomatic; however, various symptoms, including pain, limitation of movement, deformities, limb swelling, and limb length discrepancy may occur in growing children Melorheostosis may be associated with ossified and non-ossified soft tissue masses, usually surrounding the joints. The symptoms may arise due to impingement on nearby structures, either directly or through associated soft tissue masses. These masses are not necessarily a continuum of the disease lesions . Melorheostosis has been associated with various conditions, including neurofibromatosis, tuberous sclerosis, linear scleroderma, tricho-dento-osseous syndrome, rheumatoid arthritis, hypophosphatemic rickets, vascular malformations, and hemangioma . The disease may extend along the affected cortex in a proximal to distal pattern, resembling the pathognomonic “dripping candle wax” appearance Other radiologic appearances include osteoma, an osteopathia striata-like appearance, and myositis ossificans-like lesions without lamellae in soft tissues . CT show cortical thickening that might extend to the medulla, with a clear demarcation between the normal bone and the hyperostotic lesions .Additionally, clearly depict soft tissue abnormalities associated with the disease. MRI typically shows cortical hyperostosis of low signal intensity on all pulse sequences . Rarely, may show enhancing soft tissue masses that resemble aggressive neoplastic lesions PET typically show high uptake of the tracer on bone scintigraphy that crosses the adjacent joints
REFERENCES:
1. Vanhoenacker FM, De Beuckeleer LH, Van Hul W, et al. Sclerosing bone dysplasias: genetic and radioclinical features. Eur Radiol 2000;10:1423–1433. 2. Greenspan A. Sclerosing bone dysplasias: a targetsite approach. Skeletal Radiol 1991;20 3. de Vernejoul MC. Sclerosing bone disorders. Best Pract Res Clin Rheumatol 2008;22(1):71–83. 4. Van Hul W. Lessons from sclerosing bone dysplasias. Horm Res 2007;68(suppl 5):37–39. 5. Beighton P, Hamersma H. The orthopaedic implications of the sclerosing bone dysplasias. S Afr Med J 1980;58 6. Viot G, Lacombe D, David A, et al. Osteopathia striata cranial sclerosis: non-random X-inactivation suggestive of X-linked dominant inheritance. Am J Med Genet 2002;107(1):1–4. 7. Kinoshita A, Saito T, Tomita H, et al. Domainspecific mutations in TGFB1 result in CamuratiEngelmann disease. Nat Genet 2000;26(1) 8. Janssens K, Gershoni-Baruch R, Guañabens N, et al. Mutations in the gene encoding the latency-associated peptide of TGF-beta 1 cause Camurati-Engelmann disease. Nat Genet 2000;26(3)
Note:
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!