Pediatr Radiol DOI 10.1007/s00247-014-3086-x
CASE REPORT
Glomuvenous malformation: magnetic resonance imaging findings Lucia Flors & Patrick T. Norton & Klaus D. Hagspiel
Received: 14 February 2014 / Revised: 6 May 2014 / Accepted: 12 June 2014 # Springer-Verlag Berlin Heidelberg 2014
Abstract We report a case of a glomuvenous malformation involving the dorsal aspect of the right hand and distal forearm in an 11-year-old boy. He had a history of multiple vascular anomalies since birth and presented with increasing right hand pain. MRI played an important role in characterizing and determining the extent of the lesion. In particular, dynamic time-resolved contrast-enhanced MR angiography precisely defined its vascularity. The diagnosis was made histopathologically after partial resection of the lesion. Glomuvenous malformation is a rare developmental hamartoma that originates from the glomus body. Clinically they usually resemble a venous malformation but they are a different entity. In the appropriate clinical setting this rare condition must be included in the differential diagnosis of a vascular malformation, especially when subtle arterial enhancement, early venous shunting and progressive filling of dilated venous spaces are depicted on MRA.
Keywords Glomus tumor . Vascular malformations . Glomuvenous malformation . Magnetic resonance imaging . Magnetic resonance angiography . Child
of glomus tumors [1] and the most common subtype when they are multiple and familial [2]. Glomuvenous malformations present as purple-blue nodules or plaques, and they are occasionally painful and tender. Although they are a different entity, clinically they usually resemble a venous malformation and the definitive diagnosis is frequently only made by histopathological examination; they are characterized by the presence of dilated venous channels lined by clusters of glomus cells [2, 3]. Because of the scarcity of these lesions they are frequently misdiagnosed [2]. MRI is a valuable tool in delineating the extension of the lesion and may suggest the diagnosis in the appropriate clinical setting. We present a pediatric case of a glomuvenous malformation in the upper extremity with emphasis on the MR imaging findings that support the diagnosis. To our knowledge this is a unique report of the hemodynamic characteristics of glomuvenous malformations on dynamic time-resolved contrastenhanced MR angiography (MRA).
Case report
Introduction Glomuvenous malformation, also known as glomangioma, is a rare developmental hamartoma that originates from the glomus body. It is the angiomatous variant in the spectrum L. Flors : P. T. Norton : K. D. Hagspiel (*) Department of Radiology and Medical Imaging, University of Virginia Health System, Box 800170, Lee St., Charlottesville, VA 22908, USA e-mail: [email protected]
An 11-year-old boy was referred to our institution with a history of multiple cutaneous bluish vascular nodules that had been present since birth. The most prominent one was located on the dorsum of the right hand measuring approximately 4 mm. The boy complained of increasing right hand pain and discomfort without functional impairment. The pain occasionally awoke him at night. Physical examination revealed a purple-blue nodular lesion with cobblestone appearance on the dorsum of the right hand, and slight skin thickening in the thenar eminence. It was tender on deep palpation. The extremity was of normal size. He had other smaller lesions of similar characteristics on the left gluteal region,
Pediatr Radiol
with smooth muscle actin and caldesmon, supporting the diagnosis of glomuvenous malformation.
right calf and left forearm. The rest of the physical exam and the family history were unremarkable. The clinical diagnosis was venous malformation. MRI showed a multilobulated, septated lesion affecting the subcutaneous tissue of the dorsal aspect of the right hand and the second and third digits. It spread across the interosseous septum of the distal forearm. The lesion had low signal intensity on T1-weighted imaging and was highly hyperintense on T2-weighted imaging (Fig. 1). Neither bone or muscle involvement nor intra-articular extension was present. Phleboliths were not depicted. After contrast material administration, dynamic time-resolved MRA revealed focal arterial-phase enhancement in the distal aspect of the interosseous septum and the interdigital space, as well as early venous shunting (Fig. 2). The feeding artery and draining veins were not enlarged. Delayed imaging depicted heterogeneous filling of the lacunar channels of the lesion (Fig. 3). The MR imaging findings were thought to be most consistent with a mixed capillary–venous malformation [4]. A smaller lesion located on the right calf revealed the same MR imaging features. The decision was made to treat surgically the lesion on the hand because of the painful symptoms. The component affecting the dorsum of the hand was partially resected under local anesthesia. Histopathological examination revealed multiple cavernous vascular spaces lined by several layers of cuboidal cells (Fig. 4), which stained
Glomus bodies are neuromyoarterial receptors found in the reticular stratum of the dermis or in the subcutaneous tissues and are responsible for thermoregulatory function; they detect fluctuations in temperature and regulate arteriolar flow. Glomus bodies consist of an afferent artery, multiple arteriovenous anastomoses — Sucquet–Hoyer canals — and efferent veins, neuroreticular elements and lamellae of collagen [2]. They are present in high density within the fingertip pads and under the nails [2]. Glomus tumors are rare, accounting for less than 2% of soft-tissue tumors [1]. They consist of glomus cells, vascular structures, and smooth muscle tissue in various proportions, which determine the distinctive types of glomus tumor recognized by the World Health Organization [1]: solid glomus tumor, angiomatous type called glomangiomas or glomuvenous malformations, and solid type with myomatous spindle cell differentiation called glomangiomyoma. Solid glomus tumors are the most common variant (75%) [1]. Glomuvenous malformations comprise 10–20% of all glomus tumors [1, 2]. Glomus tumors are presumed to be developmental hamartomas of the glomus body and not real neoplasms [2],
Fig. 1 MRI of glomuvenous malformation in an 11-year-old boy. Coronal (a, b) and axial (c, d) MR images show a lobulated lesion (arrows) involving the dorsum of the right hand, extending into the second interdigital space and affecting the interosseous septum of the distal
forearm. The lesion is hypointense on T1-weighted imaging (a, c) and highly hyperintense on short tau inversion recovery (STIR) images (b, d) (arrows). It has a multilocular appearance from dilated channels separated by thin hypointense septae
Discussion
Pediatr Radiol
Fig. 2 MRA in the same boy as in Fig. 1. Dynamic time-resolved contrast-enhanced MR angiography with interleaved stochastic trajectories (TWIST MRA) shows the hemodynamics of the glomuvenous malformation. The parameters were TR/TE 2.93/1.21 ms, flip angle 18°, section thickness 5 mm, matrix 384 × 512, FOV 400 mm, number of sections 20, imaging time 94 s; imaging was performed after the administration of 5 cc of gadobenate dimeglumine. TWIST MRA permits the
Fig. 3 Delayed imaging of glomuvenous malformation in an 11-year-old boy. Delayed contrast-enhanced fat-suppressed 3-D T1-weighted MR images with volumetric interpolated breath-hold examination (VIBE) in the coronal (a) and axial (b) planes show nodular enhancement of the lesion (arrows). This is the typical delayed enhancement pattern of a venous malformation
acquisition of images with a temporal resolution of 2.4 s, in comparison to conventional MRA in which every dataset is acquired every 10–20 s. Images show early focal enhancement of the lesion within the second interdigital space and the distal interosseous septum (arrows), and early venous shunting (arrowheads). Note the absence of dilated arteries and draining veins, characteristic features of an arteriovenous malformation. FOV field of view, TE echo time, TR repetition time
Pediatr Radiol
Fig. 4 Histological findings in glomuvenous malformation in the 11-yearold boy. Hematoxylin and eosin; original magnification (a) x 2, (b) x 10, (c) x 20. Low-power histological images (a, b) show dilated vascular spaces (black asterisks). Several layers of glomus cells underlying the endothelium can be seen (b) (white asterisks). Glomus cells are typically cuboid in shape and have a pale eosinophilic cytoplasm on high-power microscopic view (c). They stained positively for smooth muscle actin (not shown)
though this idea is controversial. Instead of glomangioma, the term glomuvenous malformation has been proposed. Some authors consider this entity a form of venous malformation rather than a glomus tumor [3, 5]. On low-power histological examination glomuvenous malformations resemble a venous malformation, showing numerous dysplastic and dilated vascular channels with sparse fibroadipose tissue (Fig. 4) [2, 3]. High-power examination demonstrates rows of cuboidal glomus cells underlying the endothelium (Fig. 4) [2, 3]. These cells are thought to be modified smooth muscle cells [2, 3]. Glomus tumors of all types typically express smooth muscle actin [1]. H-caldesmon, a marker for smooth muscle differentiation, is also positive [1]. Although solid glomus tumors are small (1 cm or less) bluish nodules typically located under the nails [2], glomuvenous malformations tend to be larger — especially the plaque-like subtype — and they are rarely subungeal [2]. They are usually located in the skin or subcutaneous tissue [5] and can be found throughout the body. The upper extremity is the most common location [2]. Glomus tumors are characterized by a triad of symptoms: well-localized tenderness, paroxysms of pain and sensitivity to cold [2]. These symptoms are present in 42% of patients with glomuvenous malformations [2]. Clinically glomuvenous malformations resemble venous malformations, with several distinctive features: glomuvenous malformations are usually more nodular, their color ranges from pink to dark purple or dark blue, they tend to have a more raised, cobblestone-like appearance [3, 5, 6] and they may reveal hyperkeratosis [5, 6]. Unlike venous malformations, glomuvenous malformations do not tend to extend into the deep structures and they are poorly compressible [5, 6] and usually painful upon compression [5, 6]. They generally do not contain phleboliths [5, 6]. Glomus tumors can be solitary or multifocal, sporadic or familial. When multiple (25% of cases [7]), they are predominantly glomuvenous malformations [2] and tend to present at an earlier age [2, 7]. Multiple glomuvenous malformations are usually familial [1], with an autosomal-dominant inheritance with incomplete penetrance and variable expression [2, 7]. Although not histopathologically confirmed, all soft-tissue nodules in our case had the same nature, and the diagnosis of multiple glomuvenous malformations is highly probable. MRI can detect glomus tumors as small as 1–2 mm [2]. This imaging technique has an important role in evaluating the extent of these lesions and their relationship to adjacent structures, and it can also be used to assess treatment response. Glomus tumors show diffuse enhancement after gadolinium administration, especially small lesions, and more heterogeneous enhancement if they are larger [7]. Dynamic timeresolved MRA performed with intravenous administration of gadolinium-based contrast material provides valuable insights into the hemodynamics of vascular lesions, yielding crucial
Pediatr Radiol
data for diagnosis and therapy planning. This technique permits acquisition of images with high temporal resolution, and, in comparison to conventional MRA, allows separation of arterial inflow from venous drainage, and assessment of flow direction [4]. It allows differentiation of high-flow from lowflow vascular malformations [8] and has become a noninvasive alternative to conventional digital subtraction angiography [5]. In addition to the delayed pattern of enhancement, this technique allowed the depiction of focal early enhancement and venous shunting in the case presented here. These features cannot be accurately assessed in the absence of this time-resolved MRA acquisition; at our institution it is part of the MRI protocol when studying vascular lesions. To our knowledge this is a unique report of the hemodynamics of glomuvenous malformations on time-resolved MRA. We assume the histological component of the glomus body, its arterial component and the arteriovenous canal might explain the MRA findings in our case. This pattern of enhancement is also frequently encountered in mixed capillary–venous malformations, while isolated venous malformations characteristically lack early enhancement and only exhibit delayed filling of the dilated venous spaces. The final diagnosis of the presented case required histopathological and immunohistochemical examination, but it has to be noted that in the proper clinical context the above described MRI imaging features suggest the diagnosis. Although electron beam radiation, carbon and argon dioxide laser therapy and sclerotherapy have been used in the treatment of glomus lesions, complete surgical excision is usually the treatment of choice, and is generally limited to symptomatic lesions [2]. It is important to differentiate glomuvenous malformations from venous malformations because the former tend to be less responsive to sclerotherapy [3]. In our case, the lesion located in the right forearm extended deeply into the interosseous membrane and the rest of the lesions were asymptomatic; the boy underwent partial resection of the symptomatic lesion in the dorsal aspect of the hand.
In conclusion, the radiologist should be aware of this rare entity and glomuvenous malformations should be taken into consideration in the differential diagnosis of soft-tissue vascular malformations that clinically resemble a venous malformation, especially when the lesion is painful and noncompressible and when subtle arterial enhancement with early venous shunting and progressive filling of dilated venous spaces are depicted on MRA.
Conflicts of interest Dr. Hagspiel and Dr. Norton receive grant support from Siemens Medical Solutions, Malvern, PA, USA. Dr. Flors has no financial interests to disclose.
References 1. Folpe A (2002) Glomus tumours. In: Fletcher C, Unni K, Mertens F (eds) World health organization classification of tumours: pathology and genetics of soft tissue and bone. IARC Press, Lyon, pp 113–136 2. Myers RS, Lo AK, Pawel BR (2006) The glomangioma in the differential diagnosis of vascular malformations. Ann Plast Surg 57:443– 446 3. Mounayer C, Wassef M, Enjolras O et al (2001) Facial ‘glomangiomas’: large facial venous malformations with glomus cells. J Am Acad Dermatol 45:239–245 4. Flors L, Leiva-Salinas C, Maged IM et al (2011) MR imaging of softtissue vascular malformations: diagnosis, classification, and therapy follow-up. Radiographics 31:1321–1340, discussion 1340–1341 5. Behr GG, Johnson CM (2013) Vascular anomalies: hemangiomas and beyond — part 2, slow-flow lesions. AJR Am J Roentgenol 200:423– 436 6. Boon LM, Mulliken JB, Enjolras O et al (2004) Glomuvenous malformation (glomangioma) and venous malformation: distinct clinicopathologic and genetic entities. Arch Dermatol 140:971–976 7. Glazebrook KN, Laundre BJ, Schiefer TK et al (2011) Imaging features of glomus tumors. Skeletal Radiol 40:855–862 8. Kim JS, Chandler A, Borzykowski R et al (2012) Maximizing timeresolved MRA for differentiation of hemangiomas, vascular malformations and vascularized tumors. Pediatr Radiol 42:775–784
CASE REPORT
Glomuvenous malformation: magnetic resonance imaging findings Lucia Flors & Patrick T. Norton & Klaus D. Hagspiel
Received: 14 February 2014 / Revised: 6 May 2014 / Accepted: 12 June 2014 # Springer-Verlag Berlin Heidelberg 2014
Abstract We report a case of a glomuvenous malformation involving the dorsal aspect of the right hand and distal forearm in an 11-year-old boy. He had a history of multiple vascular anomalies since birth and presented with increasing right hand pain. MRI played an important role in characterizing and determining the extent of the lesion. In particular, dynamic time-resolved contrast-enhanced MR angiography precisely defined its vascularity. The diagnosis was made histopathologically after partial resection of the lesion. Glomuvenous malformation is a rare developmental hamartoma that originates from the glomus body. Clinically they usually resemble a venous malformation but they are a different entity. In the appropriate clinical setting this rare condition must be included in the differential diagnosis of a vascular malformation, especially when subtle arterial enhancement, early venous shunting and progressive filling of dilated venous spaces are depicted on MRA.
Keywords Glomus tumor . Vascular malformations . Glomuvenous malformation . Magnetic resonance imaging . Magnetic resonance angiography . Child
of glomus tumors [1] and the most common subtype when they are multiple and familial [2]. Glomuvenous malformations present as purple-blue nodules or plaques, and they are occasionally painful and tender. Although they are a different entity, clinically they usually resemble a venous malformation and the definitive diagnosis is frequently only made by histopathological examination; they are characterized by the presence of dilated venous channels lined by clusters of glomus cells [2, 3]. Because of the scarcity of these lesions they are frequently misdiagnosed [2]. MRI is a valuable tool in delineating the extension of the lesion and may suggest the diagnosis in the appropriate clinical setting. We present a pediatric case of a glomuvenous malformation in the upper extremity with emphasis on the MR imaging findings that support the diagnosis. To our knowledge this is a unique report of the hemodynamic characteristics of glomuvenous malformations on dynamic time-resolved contrastenhanced MR angiography (MRA).
Case report
Introduction Glomuvenous malformation, also known as glomangioma, is a rare developmental hamartoma that originates from the glomus body. It is the angiomatous variant in the spectrum L. Flors : P. T. Norton : K. D. Hagspiel (*) Department of Radiology and Medical Imaging, University of Virginia Health System, Box 800170, Lee St., Charlottesville, VA 22908, USA e-mail: [email protected]
An 11-year-old boy was referred to our institution with a history of multiple cutaneous bluish vascular nodules that had been present since birth. The most prominent one was located on the dorsum of the right hand measuring approximately 4 mm. The boy complained of increasing right hand pain and discomfort without functional impairment. The pain occasionally awoke him at night. Physical examination revealed a purple-blue nodular lesion with cobblestone appearance on the dorsum of the right hand, and slight skin thickening in the thenar eminence. It was tender on deep palpation. The extremity was of normal size. He had other smaller lesions of similar characteristics on the left gluteal region,
Pediatr Radiol
with smooth muscle actin and caldesmon, supporting the diagnosis of glomuvenous malformation.
right calf and left forearm. The rest of the physical exam and the family history were unremarkable. The clinical diagnosis was venous malformation. MRI showed a multilobulated, septated lesion affecting the subcutaneous tissue of the dorsal aspect of the right hand and the second and third digits. It spread across the interosseous septum of the distal forearm. The lesion had low signal intensity on T1-weighted imaging and was highly hyperintense on T2-weighted imaging (Fig. 1). Neither bone or muscle involvement nor intra-articular extension was present. Phleboliths were not depicted. After contrast material administration, dynamic time-resolved MRA revealed focal arterial-phase enhancement in the distal aspect of the interosseous septum and the interdigital space, as well as early venous shunting (Fig. 2). The feeding artery and draining veins were not enlarged. Delayed imaging depicted heterogeneous filling of the lacunar channels of the lesion (Fig. 3). The MR imaging findings were thought to be most consistent with a mixed capillary–venous malformation [4]. A smaller lesion located on the right calf revealed the same MR imaging features. The decision was made to treat surgically the lesion on the hand because of the painful symptoms. The component affecting the dorsum of the hand was partially resected under local anesthesia. Histopathological examination revealed multiple cavernous vascular spaces lined by several layers of cuboidal cells (Fig. 4), which stained
Glomus bodies are neuromyoarterial receptors found in the reticular stratum of the dermis or in the subcutaneous tissues and are responsible for thermoregulatory function; they detect fluctuations in temperature and regulate arteriolar flow. Glomus bodies consist of an afferent artery, multiple arteriovenous anastomoses — Sucquet–Hoyer canals — and efferent veins, neuroreticular elements and lamellae of collagen [2]. They are present in high density within the fingertip pads and under the nails [2]. Glomus tumors are rare, accounting for less than 2% of soft-tissue tumors [1]. They consist of glomus cells, vascular structures, and smooth muscle tissue in various proportions, which determine the distinctive types of glomus tumor recognized by the World Health Organization [1]: solid glomus tumor, angiomatous type called glomangiomas or glomuvenous malformations, and solid type with myomatous spindle cell differentiation called glomangiomyoma. Solid glomus tumors are the most common variant (75%) [1]. Glomuvenous malformations comprise 10–20% of all glomus tumors [1, 2]. Glomus tumors are presumed to be developmental hamartomas of the glomus body and not real neoplasms [2],
Fig. 1 MRI of glomuvenous malformation in an 11-year-old boy. Coronal (a, b) and axial (c, d) MR images show a lobulated lesion (arrows) involving the dorsum of the right hand, extending into the second interdigital space and affecting the interosseous septum of the distal
forearm. The lesion is hypointense on T1-weighted imaging (a, c) and highly hyperintense on short tau inversion recovery (STIR) images (b, d) (arrows). It has a multilocular appearance from dilated channels separated by thin hypointense septae
Discussion
Pediatr Radiol
Fig. 2 MRA in the same boy as in Fig. 1. Dynamic time-resolved contrast-enhanced MR angiography with interleaved stochastic trajectories (TWIST MRA) shows the hemodynamics of the glomuvenous malformation. The parameters were TR/TE 2.93/1.21 ms, flip angle 18°, section thickness 5 mm, matrix 384 × 512, FOV 400 mm, number of sections 20, imaging time 94 s; imaging was performed after the administration of 5 cc of gadobenate dimeglumine. TWIST MRA permits the
Fig. 3 Delayed imaging of glomuvenous malformation in an 11-year-old boy. Delayed contrast-enhanced fat-suppressed 3-D T1-weighted MR images with volumetric interpolated breath-hold examination (VIBE) in the coronal (a) and axial (b) planes show nodular enhancement of the lesion (arrows). This is the typical delayed enhancement pattern of a venous malformation
acquisition of images with a temporal resolution of 2.4 s, in comparison to conventional MRA in which every dataset is acquired every 10–20 s. Images show early focal enhancement of the lesion within the second interdigital space and the distal interosseous septum (arrows), and early venous shunting (arrowheads). Note the absence of dilated arteries and draining veins, characteristic features of an arteriovenous malformation. FOV field of view, TE echo time, TR repetition time
Pediatr Radiol
Fig. 4 Histological findings in glomuvenous malformation in the 11-yearold boy. Hematoxylin and eosin; original magnification (a) x 2, (b) x 10, (c) x 20. Low-power histological images (a, b) show dilated vascular spaces (black asterisks). Several layers of glomus cells underlying the endothelium can be seen (b) (white asterisks). Glomus cells are typically cuboid in shape and have a pale eosinophilic cytoplasm on high-power microscopic view (c). They stained positively for smooth muscle actin (not shown)
though this idea is controversial. Instead of glomangioma, the term glomuvenous malformation has been proposed. Some authors consider this entity a form of venous malformation rather than a glomus tumor [3, 5]. On low-power histological examination glomuvenous malformations resemble a venous malformation, showing numerous dysplastic and dilated vascular channels with sparse fibroadipose tissue (Fig. 4) [2, 3]. High-power examination demonstrates rows of cuboidal glomus cells underlying the endothelium (Fig. 4) [2, 3]. These cells are thought to be modified smooth muscle cells [2, 3]. Glomus tumors of all types typically express smooth muscle actin [1]. H-caldesmon, a marker for smooth muscle differentiation, is also positive [1]. Although solid glomus tumors are small (1 cm or less) bluish nodules typically located under the nails [2], glomuvenous malformations tend to be larger — especially the plaque-like subtype — and they are rarely subungeal [2]. They are usually located in the skin or subcutaneous tissue [5] and can be found throughout the body. The upper extremity is the most common location [2]. Glomus tumors are characterized by a triad of symptoms: well-localized tenderness, paroxysms of pain and sensitivity to cold [2]. These symptoms are present in 42% of patients with glomuvenous malformations [2]. Clinically glomuvenous malformations resemble venous malformations, with several distinctive features: glomuvenous malformations are usually more nodular, their color ranges from pink to dark purple or dark blue, they tend to have a more raised, cobblestone-like appearance [3, 5, 6] and they may reveal hyperkeratosis [5, 6]. Unlike venous malformations, glomuvenous malformations do not tend to extend into the deep structures and they are poorly compressible [5, 6] and usually painful upon compression [5, 6]. They generally do not contain phleboliths [5, 6]. Glomus tumors can be solitary or multifocal, sporadic or familial. When multiple (25% of cases [7]), they are predominantly glomuvenous malformations [2] and tend to present at an earlier age [2, 7]. Multiple glomuvenous malformations are usually familial [1], with an autosomal-dominant inheritance with incomplete penetrance and variable expression [2, 7]. Although not histopathologically confirmed, all soft-tissue nodules in our case had the same nature, and the diagnosis of multiple glomuvenous malformations is highly probable. MRI can detect glomus tumors as small as 1–2 mm [2]. This imaging technique has an important role in evaluating the extent of these lesions and their relationship to adjacent structures, and it can also be used to assess treatment response. Glomus tumors show diffuse enhancement after gadolinium administration, especially small lesions, and more heterogeneous enhancement if they are larger [7]. Dynamic timeresolved MRA performed with intravenous administration of gadolinium-based contrast material provides valuable insights into the hemodynamics of vascular lesions, yielding crucial
Pediatr Radiol
data for diagnosis and therapy planning. This technique permits acquisition of images with high temporal resolution, and, in comparison to conventional MRA, allows separation of arterial inflow from venous drainage, and assessment of flow direction [4]. It allows differentiation of high-flow from lowflow vascular malformations [8] and has become a noninvasive alternative to conventional digital subtraction angiography [5]. In addition to the delayed pattern of enhancement, this technique allowed the depiction of focal early enhancement and venous shunting in the case presented here. These features cannot be accurately assessed in the absence of this time-resolved MRA acquisition; at our institution it is part of the MRI protocol when studying vascular lesions. To our knowledge this is a unique report of the hemodynamics of glomuvenous malformations on time-resolved MRA. We assume the histological component of the glomus body, its arterial component and the arteriovenous canal might explain the MRA findings in our case. This pattern of enhancement is also frequently encountered in mixed capillary–venous malformations, while isolated venous malformations characteristically lack early enhancement and only exhibit delayed filling of the dilated venous spaces. The final diagnosis of the presented case required histopathological and immunohistochemical examination, but it has to be noted that in the proper clinical context the above described MRI imaging features suggest the diagnosis. Although electron beam radiation, carbon and argon dioxide laser therapy and sclerotherapy have been used in the treatment of glomus lesions, complete surgical excision is usually the treatment of choice, and is generally limited to symptomatic lesions [2]. It is important to differentiate glomuvenous malformations from venous malformations because the former tend to be less responsive to sclerotherapy [3]. In our case, the lesion located in the right forearm extended deeply into the interosseous membrane and the rest of the lesions were asymptomatic; the boy underwent partial resection of the symptomatic lesion in the dorsal aspect of the hand.
In conclusion, the radiologist should be aware of this rare entity and glomuvenous malformations should be taken into consideration in the differential diagnosis of soft-tissue vascular malformations that clinically resemble a venous malformation, especially when the lesion is painful and noncompressible and when subtle arterial enhancement with early venous shunting and progressive filling of dilated venous spaces are depicted on MRA.
Conflicts of interest Dr. Hagspiel and Dr. Norton receive grant support from Siemens Medical Solutions, Malvern, PA, USA. Dr. Flors has no financial interests to disclose.
References 1. Folpe A (2002) Glomus tumours. In: Fletcher C, Unni K, Mertens F (eds) World health organization classification of tumours: pathology and genetics of soft tissue and bone. IARC Press, Lyon, pp 113–136 2. Myers RS, Lo AK, Pawel BR (2006) The glomangioma in the differential diagnosis of vascular malformations. Ann Plast Surg 57:443– 446 3. Mounayer C, Wassef M, Enjolras O et al (2001) Facial ‘glomangiomas’: large facial venous malformations with glomus cells. J Am Acad Dermatol 45:239–245 4. Flors L, Leiva-Salinas C, Maged IM et al (2011) MR imaging of softtissue vascular malformations: diagnosis, classification, and therapy follow-up. Radiographics 31:1321–1340, discussion 1340–1341 5. Behr GG, Johnson CM (2013) Vascular anomalies: hemangiomas and beyond — part 2, slow-flow lesions. AJR Am J Roentgenol 200:423– 436 6. Boon LM, Mulliken JB, Enjolras O et al (2004) Glomuvenous malformation (glomangioma) and venous malformation: distinct clinicopathologic and genetic entities. Arch Dermatol 140:971–976 7. Glazebrook KN, Laundre BJ, Schiefer TK et al (2011) Imaging features of glomus tumors. Skeletal Radiol 40:855–862 8. Kim JS, Chandler A, Borzykowski R et al (2012) Maximizing timeresolved MRA for differentiation of hemangiomas, vascular malformations and vascularized tumors. Pediatr Radiol 42:775–784
