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CT imaging
Rev Esp Med Nucl Imagen Mol. 2017;36(3):197–198
Interesting images
Hemorrhagic pseudotumors of iliac bones in Noonan syndrome: PET/CT imaging Pseudotumores hemorrágicos de los huesos ilíacos en el síndrome de Noonan: imágenes de PET/TC K.D. Nguyen, B.D. Nguyen ∗ Department of Radiology, Nuclear Medicine Division, Mayo Clinic Arizona, Scottsdale, AZ, USA
A 44-year-old man presented with bilateral iliac bone lesions on CT (Fig. 1A). His clinical history was remarkable for Noonan syndrome with factor XI deficiency, borderline factor VIII and multiple back surgeries for severe scoliosis including Harrington rod
placement and vertebral bone grafting. Initial biopsy of the iliac bone lesions was non-diagnostic with only evidence of necrotic debris. Subsequent PET/CT showed borderline hypermetabolic lesions of the iliac bones non-specific for benign processes or
Fig. 1. (A) Initial axial CT showing lesions arising from iliac bones at the prior sites of bone harvest for spine fusion and graft (arrows). (B and C) Axial PET/CT images, at two different levels of the pelvis, showing the hemorrhagic pseudotumors as lobulated masses arising from both iliac bones with lytic osseous appearance and borderline hypermetabolic features (SUV: 3.5, arrows). (D and E) Two-year serial MR monitoring, starting at the time of the CT and PET/CT imaging, showing the progressive growth of the iliac bone lesions with adjacent soft tissue involvement (arrows).
∗ Corresponding author. E-mail address: [email protected] (B.D. Nguyen). http://dx.doi.org/10.1016/j.remn.2016.08.006 2253-8089 2016 Elsevier Espana, ˜ S.L.U. y SEMNIM. All rights reserved. 2253-654X/©
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K.D. Nguyen, B.D. Nguyen / Rev Esp Med Nucl Imagen Mol. 2017;36(3):197–198
Fig. 2. Surgical specimen of the hemorrhagic pseudotumor.
neoplasms with low degree of aggressivity (Fig. 1B and C, SUV: 3.5). Open biopsy was prompted by the progressively enlarging masses of the iliac bones seen on serial MR exams during a two-year surveillance (Fig. 1D and E). The surgical specimen consisted of collections of hemorrhagic, rubbery and friable material partially encapsulated by membranous tissue. It contained fragments of dense fibrous connective, adjacent adipose tissue and skeletal muscle, with acute and chronically inflamed granulation tissue and rare focal areas of polarizable crystalline material associated with foreign-body giant cell reaction (Fig. 2). The pathologic findings, negative for malignancy, were compatible with hemorrhagic pseudotumors. Noonan syndrome is a genetic disorder caused by mutation in the RAS/mitogen-activated protein kinase (MPAK) signaling
pathway, which is a critical component of developmental growth.1 Affecting about 1:1000–2500 live births, the major symptoms of this disorder include facial dysmorphology, short stature, pectus excavatum, and bleeding diathesis.1 The blood disorders increase the risk of hemorrhagic pseudotumor occurrence in Noonan syndrome patients, as seen in the 44-year-old man with prior bilateral iliac bone harvest related to spine scoliosis surgery and graft. Hemorrhagic pseudotumors are more often encountered in hemophilia, occurring in 1–2% of affected patients.2 Repeat hemorrhages can lead to the growth of expansile osseous lesions, with adjacent soft tissue protrusion, that may be difficult to differentiate from real bone neoplasms. Anatomic and functional imaging such as CT, MR and PET/CT cannot accurately identify hemorrhagic or hemophilic pseudotumors, which consist of intraosseous hemorrhagic collections exhibiting lytic features and heterogeneous components of different stages of bleeding and possible adjacent soft tissue involvement. Open surgical biopsy is necessary for the definitive diagnosis of hemorrhagic pseudotumors. Conflict of interest The authors have no conflict of interest to declare. References 1. Smpokou P, Tworog-Dube E, Kucherlapati RS, Roberts AE. Medical complications, clinical findings, and educational outcomes in adults with Noonan syndrome. Am J Med Genet A. 2012;158A:3106–11. 2. Kerr R. Imaging of musculoskeletal complications of hemophilia. Semin Musculoskelet Radiol. 2003;7:127–36.
Interesting images
Hemorrhagic pseudotumors of iliac bones in Noonan syndrome: PET/CT imaging Pseudotumores hemorrágicos de los huesos ilíacos en el síndrome de Noonan: imágenes de PET/TC K.D. Nguyen, B.D. Nguyen ∗ Department of Radiology, Nuclear Medicine Division, Mayo Clinic Arizona, Scottsdale, AZ, USA
A 44-year-old man presented with bilateral iliac bone lesions on CT (Fig. 1A). His clinical history was remarkable for Noonan syndrome with factor XI deficiency, borderline factor VIII and multiple back surgeries for severe scoliosis including Harrington rod
placement and vertebral bone grafting. Initial biopsy of the iliac bone lesions was non-diagnostic with only evidence of necrotic debris. Subsequent PET/CT showed borderline hypermetabolic lesions of the iliac bones non-specific for benign processes or
Fig. 1. (A) Initial axial CT showing lesions arising from iliac bones at the prior sites of bone harvest for spine fusion and graft (arrows). (B and C) Axial PET/CT images, at two different levels of the pelvis, showing the hemorrhagic pseudotumors as lobulated masses arising from both iliac bones with lytic osseous appearance and borderline hypermetabolic features (SUV: 3.5, arrows). (D and E) Two-year serial MR monitoring, starting at the time of the CT and PET/CT imaging, showing the progressive growth of the iliac bone lesions with adjacent soft tissue involvement (arrows).
∗ Corresponding author. E-mail address: [email protected] (B.D. Nguyen). http://dx.doi.org/10.1016/j.remn.2016.08.006 2253-8089 2016 Elsevier Espana, ˜ S.L.U. y SEMNIM. All rights reserved. 2253-654X/©
198
K.D. Nguyen, B.D. Nguyen / Rev Esp Med Nucl Imagen Mol. 2017;36(3):197–198
Fig. 2. Surgical specimen of the hemorrhagic pseudotumor.
neoplasms with low degree of aggressivity (Fig. 1B and C, SUV: 3.5). Open biopsy was prompted by the progressively enlarging masses of the iliac bones seen on serial MR exams during a two-year surveillance (Fig. 1D and E). The surgical specimen consisted of collections of hemorrhagic, rubbery and friable material partially encapsulated by membranous tissue. It contained fragments of dense fibrous connective, adjacent adipose tissue and skeletal muscle, with acute and chronically inflamed granulation tissue and rare focal areas of polarizable crystalline material associated with foreign-body giant cell reaction (Fig. 2). The pathologic findings, negative for malignancy, were compatible with hemorrhagic pseudotumors. Noonan syndrome is a genetic disorder caused by mutation in the RAS/mitogen-activated protein kinase (MPAK) signaling
pathway, which is a critical component of developmental growth.1 Affecting about 1:1000–2500 live births, the major symptoms of this disorder include facial dysmorphology, short stature, pectus excavatum, and bleeding diathesis.1 The blood disorders increase the risk of hemorrhagic pseudotumor occurrence in Noonan syndrome patients, as seen in the 44-year-old man with prior bilateral iliac bone harvest related to spine scoliosis surgery and graft. Hemorrhagic pseudotumors are more often encountered in hemophilia, occurring in 1–2% of affected patients.2 Repeat hemorrhages can lead to the growth of expansile osseous lesions, with adjacent soft tissue protrusion, that may be difficult to differentiate from real bone neoplasms. Anatomic and functional imaging such as CT, MR and PET/CT cannot accurately identify hemorrhagic or hemophilic pseudotumors, which consist of intraosseous hemorrhagic collections exhibiting lytic features and heterogeneous components of different stages of bleeding and possible adjacent soft tissue involvement. Open surgical biopsy is necessary for the definitive diagnosis of hemorrhagic pseudotumors. Conflict of interest The authors have no conflict of interest to declare. References 1. Smpokou P, Tworog-Dube E, Kucherlapati RS, Roberts AE. Medical complications, clinical findings, and educational outcomes in adults with Noonan syndrome. Am J Med Genet A. 2012;158A:3106–11. 2. Kerr R. Imaging of musculoskeletal complications of hemophilia. Semin Musculoskelet Radiol. 2003;7:127–36.