Glomangiomatosis of the Sciatic Nerve: a Case Report and Review of the Literature

Skeletal Radiol (2017) 46:807–815 DOI 10.1007/s00256-017-2594-9

CASE REPORT

Glomangiomatosis of the sciatic nerve: a case report and review of the literature

Rajendra Kumar1 & Lisa Vu1,2 & John E. Madewell1 & Cynthia E. Herzog3 & Justin E. Bird4

Received: 3 August 2016 /Revised: 19 January 2017 /Accepted: 7 February 2017 /Published online: 17 March 2017 # ISS 2017

Abstract Glomus tumors are hamartomas, which tend to oc- temperature regulation via arteriovenous shunting of cur in sites rich in glomus bodies, such as the subungual re- blood [1, 2]. Glomus tumors are uncommon benign tu- gions of digits or the deep dermis of the palm, wrist, forearm, mors that tend to occur in areas rich in glomus bodies, and foot. Very rarely, they may involve peripheral nerves. We such as subungual regions of the digits and deep dermis describe a patient, who, following surgical resection of a sol- in the distal upper and lower extremities [1–3]. Although itary glomus tumor of the left distal sciatic nerve in his teens, glomus tumors can occur in any location, even those not had recurrence with development of multiple tumors in the known to contain glomus bodies, involvement of periph- course of the nerve over several years. To our knowledge, this eral nerves is exceedingly rare [1, 4]. Only 12 cases of is the only known case of glomangiomatosis involving a ma- intraneural glomus tumors, including a recent case of jor peripheral nerve. multiple glomus tumors involving a digital nerve, have been reported in the literature (Table 1). However, to our Keywords Glomus tumor . Peripheral nerve . Sciatic nerve . knowledge, no case of recurrent or multiple glomus tu- Peripheralnervetumor .Intraneuralglomustumor .Intraneural mors diffusely involving a major nerve has so far been glomangiomatosis described. We present an unusual patient who, after a previous surgical resection of a glomus tumor of the distal left sciatic nerve Introduction during his teens, experienced recurrence with multiple tumors involving the nerve over a period of several years. One of The neuromyoarterial glomus is ubiquitous in the soft those recurrent intraneural glomus tumors on histopathology tissues, especially dermis of the skin, and functions in demonstrated early malignant change, whereas another tumor exhibited a plexiform pattern, reminiscent of neurofibromatosis type 1 (NF1). * Rajendra Kumar [email protected]

Case report 1 Department of Diagnostic Imaging, The University of Texas MD Anderson Cancer Center, Unit 1515 Holcombe Boulevard, Unit 1495, Houston, TX 77030, USA A 14-year-old boy presented at an outside medical facility with a 4-year history of left leg cramping, both at rest and with 2 Present address: South Sound Radiology, 3417 Ensign Road NE, Olympia, WA 98506, USA physical activity, which was relieved with squeezing of the calf and by elevating the leg. Over-the-counter pain medications 3 Department of Pediatrics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Unit 87, gave him no relief. He denied any sensory loss or muscle Houston, TX 77030, USA weakness in his left lower extremity. The physical examination 4 Department of Orthopedic Oncology, The University of Texas MD was non-contributory. Magnetic resonance imaging (MRI) Anderson Cancer Center, 1515 Holcombe Boulevard, Unit 1448, showed a small soft-tissue mass measuring 6.7× 4.3× 3.0 cm Houston, TX 77030, USA (craniocaudal × transverse × anteroposterior) at the distal 808 Skeletal Radiol (2017) 46:807–815

Table 1 Summary of previously reported cases of intraneural gliomasa

Reference History Nerve Lesion size Surgical findings Pathology Follow-up involvement (CC×TR×AP)

Scheithauer 32-year-old man. LLE Sciatic nerve 7 × 2.8 × 1.6 cm Oblong with moderate Glomangioma Improved symptoms with et al. [2] radicular pain, vascularity, partial no recurrence 11 months weakness, and left food infiltration and post-resection drop adherence of the sciatic nerve fascicles Scheithauer 31-year-old man, Median nerve 2.5 cm length Purple, vascular mass Glomus Stable neurological et al. [2] progressive left hand within median nerve tumor function with resolved weakness and forearm fascicle pain 7 months atrophy post-surgery Wing & 37-year-old man. Radiating Right 1 cm Lesion shelled out with Glomus NA Leavitt pain in the right leg and common ease tumor [5] tingling in lateral toes. peroneal Muscle atrophy Kline et al. 46-year-old man. Ulnar digital “Pea size” White mass arising within Glomus Resolution of pain. [6] Numbness and tingling nerve of left the nerve fascicle, tumor Residual numbness of thumb and index thumb expanded epineurium along ulnar surface of finger. Cold thumb insensitivity. Positive Phalen’s and Tinel’stests Tropet et al. 16-year-old girl. Right sciatic 5 cm Oval firm yellowish, Glomus Partial recovery of motor [7] Non-radiating persistent well-circumscribed tumor functionat 2-year right thigh pain and tumor replacing nerve post-operative follow-up tenderness tissue Smith et al. 62-year-old woman. Left radial 2.5 cm Well-encapsulated lesion Glomus Immediate resolution of [8] Paroxysmal pain in shelled out with tumor pain without recurrence upper arm and radiating complete preservation of 1-year post-operatively to index and middle the nerve fascicles fingers Calonje and 67-year-old woman. Pain Cutaneous 1 cm Local excision Glomus No recurrent Fletcher nerve in tumor disease14 years [9] shoulder post-operatively Donato 56-year-old man. Distal Sural nerve 400 μm Sural nerve biopsy Glomangioma NA et al. [10] sensorimotor neuropathy Mitchell 60-year-old woman. Ulnar digital 0.7 cm Small tumor midway along Glomus Resolution of pain et al. [4] Painful mass. No nerve the distal phalanx tumor immediately with no neurological deficits. intimately involving the recurrence 2 years ulnar nerve with post-operatively complete resection. Kim and 44-year-old woman. Ulnar digital 1 × 0.5 × 0.5 cm Encapsulated tumor Glomus Symptoms resolved, no Jung [11] Painful mass in 4th web nerve, right resected tumor recurrence at 3-year and paresthesia in ring ring finger postoperative follow-up finger Park et al. 56-year-old man, Left femoral 2.5 cm Surgical resection Glomus Resolution of pain. No [12] progressive left anterior nerve tumor recurrence at 2-year thigh pain post-operative follow-up Wong et al. 50-year-old woman. Pain Radial digital Two 5-mm 2 small with 3 additional Glomus Resolution of pain and [13] and hypersensitivity on nerve of lesions tiny tumors connected tumors sensitivity. 10-month the radial side of her right on a single swollen follow-up, no recurrent right middle finger. middle fascicle within the digital symptoms Positive Tinel’s test finger nerve. The fascicle with 5 tumors was excised.

CC craniocaudal, TR transverse, AP anteroposterior a Modified after Mitchell et al [4] sciatic nerve in the left thigh (those pre-operative MR images bluish nodule measuring roughly 4.3 × 3.0 × 6.7 cm. Given its are not available). An excisional biopsy of the resected mass intimate relationship with the sciatic nerve, the mass could not from the sciatic nerve at the outside hospital revealed a small be completely resected. The tumor was thought to be a low- Skeletal Radiol (2017) 46:807–815 809 grade undifferentiating sarcoma, and the patient was referred to for 10–15 seconds at a time, and was poorly managed with our institution for further evaluation and treatment. strong pain medications. He had mildly diminished tactile sen- Physical examination at our institution revealed a surgical scar sation in the L4, L5, and S1 dermal distribution. Overall, he roughly 8 cm in length on the left distal posterior thigh. No focal maintained normal left lower extremity muscle strength and soft-tissue mass was palpable. No sensory or motor loss, or ab- reflexes, but continued to have mildly decreased dorsiflexion normal reflexes in the left lower extremity were present. MRI in his left foot. demonstrated a well-defined soft-tissue nodule, about Follow-up MRI of the left thigh 16 months after surgery 7.9 × 2.5 × 2.6 cm (craniocaudad × transverse × anteroposterior) revealed that besides a slight increase in size of the residual in size, at the sciatic nerve near its bifurcation in the left distal intraneural tumor nodule, a few new small tumor nodules had posterior thigh (Fig. 1). appeared in the distal sciatic nerve, indicating disease progression Because of persistent episodic left lower leg pain, the patient (Fig. 2). This MRI also included for the first time the upper left underwent surgery at our institution. An ovoid soft-tissue tumor thigh, revealing an additional enhancing glomus tumor in the completely encasing the left distal sciatic nerve and adjoining proximal sciatic nerve (Fig. 3). The left lower leg pain continued tibial and common peroneal nerve branches, measuring approx- to worsen, requiring even more potent medications for pain relief. imately 5.0 × 3 × 2.5 cm (craniocaudad × transverse × Serial follow-up MRI of the left thigh at roughly 4- and 12- anterioposterior), was excised. However, as the intraneural tumor month intervals following surgery revealed a diffusely thickened could not be completely resected without sacrificing the entire and multinodular sciatic nerve with multiple intraneural glomus nerve, a minimal amount of the intraneural tumor was left tumors (Figs. 4, 5). Also, over these years, the left lower leg pain behind. continued to worsen, became almost constant, and required Histopathological evaluation of the previous biopsy tissue opiates. material from the outside hospital and the newly resected tis- Now almost suicidal, the agonized patient demanded sue at our hospital from the left distal sciatic nerve mass re- permanent relief from the intractable pain in his left lower vealed it to be composed of solid nests and sheets of enlarged leg, and opted for surgery. Approximately 24 cm length of small epithelioid cells with monotonous round nuclei, mostly diffusely thickened and nodular left sciatic nerve, bearing surrounded by capillaries or thin-walled vessels. Immuno- multiple intraneural nodules, extending proximally from histochemistry stain for SMA, a myogenic marker, was posi- the level of the ischial tuberosity to a level just beyond the tive in the tumor cells of the initial tissue, confirming myo- sciatic nerve bifurcation, was resected (Fig. 6). On histopa- genic dedifferentiation of the tumor. S-100 protein and keratin thology, the resected segment of the thickened nerve stains were negative. Other markers, including desmin, p53, was found to be diffusely infiltrated with glomus cells, and Ki67, were not contributory. The histopathological find- which were also reactive for SMA (Fig. 7). The proliferative ings were consistent with a glomus tumor of the sciatic nerve. activity, seen in approximately 10% of the tumor cells, Over the course of next 12 years, the patient continued to have measured a low level of Ki67. No high-grade sarcomatous foot drop and gradually progressive intractable episodic parox- transformation was detected in any of these glomus ysmal burning, throbbing, and sharp stabbing pain radiating tumors. However, increased mitotic activity in some of the down his left lower leg, which occurred every few hours, lasting enlarged glomus cells in one of the tumor nodules was

a T1WI b Fat-satT2WI c T1WI+C

Fig. 1 20 April 2001. Glomangioma arising in left distal sciatic nerve. on fat-sat T2WI (b), and enhances mildly on post-contrast T1WI (c). Note MRI of left thigh in axial plane shows well-circumscribed round tumor excisional biopsy scar at posterior left thigh. The tumor could only be (arrows), which is isointense on T1WI (a), heterogeneously hyperintense partially excised 810 Skeletal Radiol (2017) 46:807–815

abT1WI Fat-sat T2WI cT1W1+C

d T1WI e Fat-sat T2WI f T1+C

Fig. 2 8 August 2002. Follow-up MRI of the left thigh in the axial plane at the tibial and peroneal branches of the left sciatic nerve (arrows)were shows that the residual tumor (arrows) in the distal sciatic nerve is a also d isointense on T1W, e hyperintense on fat-saturated T2WI, and f isointense on T1WI, b hyperintense on fat-saturated T2WI, and c mildly enhancing on post-contrast T1WI enhances mildly on post-contrast T1WI. Additional new small nodules concerning for early malignant change, whereas another tu- and the intractable pain in the left leg was mostly gone. He mor nodule showed plexiform neural architecture suggestive no longer required opiates, but still had left foot drop and some of NF1. sensory loss in his lower left leg. Follow-up MRI at this time At the 7-month postoperative follow-up after the nerve revealed enhancing residual small intraneural tumors in the resection, the patient’s symptoms had markedly improved, left proximal thigh and popliteal fossa (Fig. 8).

T1WI a Fat sat-T2WI b Fat-sat T1WI+C c

Fig. 3 8 August 2002. MRI of proximal left thigh in axial plane shows additional small sciatic nerve glomangioma in upper sciatic nerve, which is isointense on T1WI (a), hyperintense on T2WI (b), and enhances on post-contrast fat-sat T1WI (c). This region was never imaged previously Skeletal Radiol (2017) 46:807–815 811

Fig. 4 11 July 2005. Sagittal fat- a b sat T2 WI of left thigh shows Fat-sat T2WI Fat-sat T2WI diffusely thickened sciatic nerve with glomus tumors. Follow-up sagittal fat-sat T2WI on 19 January 2006 shows disease progression with increased thickening and nodularity of left sciatic nerve (b)

07/11/2005 01/19/2006

Discussion more often due to a glomus tumor that may compress an adjoining nerve and cause peripheral neuropathy [2, 16]. The neuromyoarterial glomus, normally located deep in the stra- Nearly all glomus tumors are benign, and represent nearly tum reticularis of the dermis, participates in thermoregulation via 2% of soft-tissue tumors [2, 3].Onlyabout1%ofglomustumors shunting of the blood [1–3, 14]. Areas rich in glomus bodies tend to be malignant [1, 3]. Extra-cutaneous soft-tissue location, inhabit the subungual regions of the digits and the deep dermis non-soft-tissue location, or a multiplicity of these benign tumors of the palm, wrist, forearm, and foot. Thus, it is not surprising should not indicate malignancy [1]. Although reported in all that most glomus tumors tend to occur at these sites [1, 3]. ages, most glomus tumors are seen in young adults [14]. Up to However, glomus tumors can occur in virtually any location, 75% of these tumors occur in the hand, two-thirds in a even in sites not known to have glomus bodies, such as the subungual location, as painful, tender, tiny soft-tissue nodules mediastinum, nasal cavity, tongue, lung, trachea, mediastinum, [1–3, 14, 17]. Heys et al. reported subungual tumors to be more GI tract, penis, cervix, vagina, bone, pterygoid fossa, knee, and common in men with a ratio of 1.7:1, whereas others have stated blood vessels [1–3, 15]. Rarely, a coccygeal glomus tumor with women to be affected twice as commonly as men [1–3]. Most coccygodynia may mimic pilonidal sinus [2, 3]. Glomus tumor glomus tumors are solitary. Among the 74 cases of glomus is believed to arise from pericytes, perivascular smooth muscle tumors reported by Glazebrook et al., 49 occurred in upper ex- cells, as they differentiate into glomus cells. This also explains tremities, and 34 in the lower extremities [17]. In contrast, the the occurrence of a glomus tumor at an ectopic site without pre- extradigital glomus tumor had equal distribution in the upper existing glomus bodies [1, 3]. Glomus tumors arising in periph- and lower extremities [18]. In adults, multiple tumors, making eral nerves are extremely rare [2, 14]. Nerve involvement is up only 2–3%, tend to occur in the upper extremities of mostly

Fig. 5 15 February 2013. Further disease progression in proximal abFat-sat T2WI Fat-sat T2WI (a) and distal (b) portions of left sciatic nerve in follow-up coronal fat-sat T2 WI indicating diffuse glomangiomatosis 812 Skeletal Radiol (2017) 46:807–815

enclosed in a fibrous capsule, is richly surrounded by nerve fibers [1–3]. The glomus tumors, depending on their predomi- nant histological constituent components, are sub-classified as solid glomus tumors, with poor vasculature and scant smooth muscle components; glomangiomas, with prominent vascular components; and glomangiomyomas, with prominent vascular and smooth muscle components [1, 3, 4]. Among these, the solid glomus tumor is the most common (75%), followed by glomangioma (20%) and glomangiomyoma (5%) [1]. Most tumors involving peripheral nerves are nerve sheath tumors, such as schwannomas and neurofibromas [2]. Rare benign epineurial tumors include hemangioma and angiomatosis, paraganglioma, lipoma, meningioma, hemangioblastoma, adrenal adenoma and mucoid cyst [2]. Fig. 6 Photograph of excised thickened and nodular left sciatic nerve Rare benign intraneural tumors affecting peripheral nerves diffusely involved with multiple glomangiomas tend to be fibrolipoma, hemangioma, lipoma, ganglion cyst, meningioma, epithelioid nerve sheath tumor and glomus tu- men, are rarely subungual, and often poorly marginated [1–3, mor [2]. All these nerve-related benign tumors have charac- 14]. However, in a reported series of 13 patients with multiple teristic histological diagnostic features. glomus tumors (glomangiomatosis), most (77%) occurred in the Only 12 cases of intraneural glomus tumors involving pe- lower extremities [17]. Multiple glomus tumors, making up to ripheral nerves, ranging from small digital nerves to large 10% of pediatric cases, tend to be asymptomatic, although, at peripheral nerves, all in adults, have been reported (Table 1). times, both painful and painless tumors may co-exist [1, 3, 14, Among these, 7 intraneural tumors were in the upper extrem- 19]. The rare congenital multiple tumors, inherited as an autoso- ities, and 5 in the lower extremities. In the upper extremities, 1 mal dominant transmission with incomplete penetration and var- tumor involved the median nerve [2], 1 the radial nerve [8], 4 iable expressivity due to a mutation located on chromosome the digital nerves of the fingers [4, 11–13], and 1 the cutane- 1p21–22, usually appear as disseminated, plaque-like small ous nerve at the shoulder [9]. In the lower extremities, 2 oc- maculopapular or nodular skin lesions [3, 16]. curred in the sciatic nerve [2, 7], and 1 each in the femoral Glomus tumor is a hamartoma, composed of a specialized nerve [12 ], the common peroneal nerve [5], and the sural arteriovenous anastomotic complex lined by proliferating nerve [10]. The tumors ranged from <1 mm to about 7 cm uniform-appearing plump glomus cells in a sheet or nest pattern. in size. Interestingly, the diagnosis was rarely suggested pre- The endothelial phenotype cells lining the vascular channels, the operatively. All were discrete solitary tumors, with the excep- Sucquet–Hoyer canals, stain strongly in reaction to SMA on tion of one patient who had multiple tumors involving the immunohistochemistry. The entire anastomotic structure, digital nerve of the middle finger [13]. This is the only

Fig. 7 a Low power (H&E, 20x) photomicrograph shows multiple small round nuclei and interspersed with small vascular channels. nodules scattered in fibrous stromal tissue. b. High power (H&E, 200x) Immunohistochemical study (inset) reveals the tumor cells are reactive shows the cellular tumor is composed of monotonouscuboidal cells with for SMA (smooth muscle actin), compatible with glomus tumor Skeletal Radiol (2017) 46:807–815 813

Fig. 8 27 September 2013. Follow-up axial fat-sat T2WIof a Fat-sat T2 b Fat-sat T2 left thigh after surgical resection of about 23 cm length of sciatic nerve show residual intraneural glomus tumors (arrows)at excision sites in upper thigh (a) and popliteal fossa (b)

reported case of multiple intraneural glomus tumors affecting stopping afferent blood flow to the tumor, either by squeezing, a peripheral nerve. Two cases of solitary intraneural glomus or raising the affected part, as was initially observed in our tumor in the sciatic nerve have been described [2, 7]. patient. The pain may be severe enough to have an impact on However, unlike those 2 patients, our patient had multiple the quality of life [2]. The exact cause of the pain is not and recurrent glomus tumors that diffusely involved the sciatic completely understood. Recently, nerve fibers containing the nerve over several years. Moreover, all other patients with pain neurotransmitter substance P have been identified in these intraneural glomus tumors had complete relief of the pain tumors [22]. Cold intolerance, paresthesia, and sensory and mus- following surgical excision of the tumor, whereas our patient cle loss in the distribution of the affected nerve are variable [2, 4, continued to suffer for many years, despite the initial resection 14, 17]. A case of multiple glomus tumors involving the radial of a solitary tumor in his distal sciatic nerve, and he continued digital nerve of the right middle finger of a 50-year-old woman to develop additional intraneural tumors. Histopathology of has recently been reported by Wong et al. [13]. The patient had the resected sciatic nerve in our patient revealed diffuse in- 10-year history of pain and cold intolerance of the finger. volvement with intraneural glomus tumors, suggesting that About 1% of glomus tumors are malignant [2, 3, 23–25]. our patient might have the rare but distinct variant of glomus Local recurrence may occur in up to 50% following resection tumor involving a peripheral nerve, in which the tumor tends of these tumors, and 25% may metastasize [2, 23–25]. to be an infiltrating, larger, and more deep-seated lesion that Malignant glomus tumors may appear de novo, arise in benign often recurs [9]. glomus tumors, or look benign, but locally infiltrating [23]. Clinically, a cutaneous glomus tumor, depending on its depth Folpe et al. have described the following histological criteria and skin color, appears as a small, solitary, red-to-purple-to-blue for malignancy in a glomus tumor: large size (>2.0 cm), deep discoloration or nodule [1, 3, 14, 17]. The lesion is usually less location, nuclear atypia, including prominent nucleoli and pleo- than 1 cm in diameter, although larger cutaneous tumors up to morphism, increased mitotic activity (>5 per 50 high-power 3 cm have been reported. When multiple, these tumors tend to field), and a tendency to exhibit spindle or round cell features be even smaller, about 0.1 to 0.3 cm in diameter [1, 2]. resembling fibrosarcoma, leiomyosarcoma, or Ewing sarcoma Cutaneous solid glomus tumors are more commonly associated [26]. If these histological criteria are met, the risk of metastases with the classic clinical triad of excruciating paroxysmal pain out exceeds 25%. However, the tumors with some but not all of of proportion to the tumor size, pin-point tenderness, and cold these criteria, are best described as glomus tumors with uncertain hypersensitivity [2, 3, 17]. Both Love’s pin test and Hildreth’s malignant potential [26]. Despite the protracted course, the dif- test have been found to be clinically useful in the diagnosis of fuse infiltration, tumor recurrence, and presence of nuclear these cutaneous glomus tumors [20, 21]. atypia with positive nuclear immune reactivity with p53 in one Although a glomus tumor involving a superficial nerve may of the tumor nodules involving the sciatic nerve in our patient be palpable, the deep-seated small intraneural glomus tumors suggested low-grade malignancy. Among the malignant often escape detection on clinical examination [4, 14, 17]. intraneural tumors, differential diagnoses include epithelioid Local or radiating pain and tenderness in the distribution of the leiomyosarcoma, metastasis, and malignant glomus tumor [2]. nerve involved is the usual complaint. The pain may vary from To our knowledge, no case of malignant intraneural glomus mild to severe in intensity, episodic or constant, burning or tumor has yet been reported. shooting, often intolerable, and usually unresponsive to conven- A rare case of multiple cutaneous glomus tumors in a pa- tional pain therapies [2]. Often, the pain can be interrupted by tient with NF1 has been described in the literature [27]. The 814 Skeletal Radiol (2017) 46:807–815 glomus tumors associated with NF1 are believed to result Acknowledgements We are grateful to Jeanne M. Meis, MD, from biallelic inactivation of the NF1 suppressor gene. Department of Pathology, UT, MD Anderson Cancer Center, Houston, TX, USA, for her valuable assistance in the preparation of this These cutaneous tumors exclusively involve fingers, specifi- manuscript. cally fingertips, where they tend to be multiple, and do not involve the nerves [4, 28]. In our patient, one of the recurrent Compliance with ethical standards intraneural glomus tumors in the sciatic nerve exhibited a plexiform pattern on histopathology, suggesting NF1 involve- Conflicts of interest None. ment. However, as far as we know, our patient fulfilled none of the diagnostic criteria of the disease. Although ultrasound is routinelyusedinthedetectionand References biopsy of glomus tumors involving superficial digital nerves, MRI can be highly rewarding in the diagnosis and management 1. Gombos Z, Zhang PJ. Glomus tumor. Arch Pathol Lab Med. – of an intraneural tumor as it provides important information 2008;132:1448 52. 2. Scheithauer BW, Rodriguez FJ, Spinner RJ, Dyck PJ, Salem A, about its size, location, configuration, and relationship with the Edelman FL, et al. Glomus tumor and glomangioma of the nerve. nerve involved [14, 17, 29–31]. Multiple tumors along the Report of 2 cases. 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