Phantom limb pain, traumatic neuroma, or nerve sheath tumor? Illustrative case

BACKGROUND

Phantom limb pain and traumatic neuromas are not commonly seen in neurosurgical practice. These conditions can present with similar symptoms; however, management of traumatic neuroma is often surgical, whereas phantom limb pain is treated with conservative measures.

OBSERVATIONS

A 77-year-old female patient with a long-standing history of an above-the-knee amputation experienced severe pain in her right posterior buttocks area for several years' duration, attributed to phantom limb pain, which radiated down the stump of her leg and was treated with a variety of conservative measures. A recent exacerbation of her pain led to a prolonged hospitalization with magnetic resonance imaging of her leg stump, revealing a mass in the sciatic notch, at a relative distance from the stump. The anatomical location of the mass on the sciatic nerve in the notch led to a presumed radiological diagnosis of nerve sheath tumor, for which she underwent excision. At surgery, a neuroma of the proximal portion of the transected sciatic nerve that had retracted from the amputated stump to the notch was diagnosed.

LESSONS

Traumatic neuromas of transected major nerves after limb amputation should be considered in the differential diagnosis of phantom limb pain.

Cervical intradural traumatic neuroma without history of trauma: illustrative case

BACKGROUND

Traumatic neuroma typically refers to a reactive process in the injured peripheral nerve, characterized by an excessive growth of axons, Schwann cells, and fibroblasts at the proximal end of the nerve after its interruption. The authors report a case of a traumatic neuroma in the cervical nerve root in a patient with no history of trauma.

OBSERVATIONS

The patient presented with sensation loss in the right-hand ulnar distribution, right flank around the T4-11 region, and right small toe along with motor power weakness over the right upper and lower extremity. Magnetic resonance imaging revealed an intradural extramedullary mass lesion with extension along the C7 nerve root. Histological examination showed traumatic neuroma. A total resection of the lesion along with the resolution of sensory and motor deficits was achieved directly after surgery.

LESSONS

Traumatic neuroma should always be kept in the armamentarium for diagnosis of an intradural nerve sheath tumor.

The Double-Opposing Adipofascial Interposition Flap: A Novel Technique to Prevent Scar Tethering and Symptomatic Neuroma of the Superficial Radial Nerve After Trauma

The superficial radial nerve (SRN) is vulnerable to injury following trauma with a high incidence of resultant nerve tether and neuroma formation. The SRN has an anatomical predisposition to neuroma formation, with research indicating that its propensity to neuroma development is out of proportion with its likelihood for injury. In addition, SRN neuromas have been described as one of the more painful and difficult neuromas to manage. Despite this, the published literature to date is chiefly focused on neuroma and scar tether treatment options rather than more impactful work on neuroma prevention, which can be safely delivered at the time of primary surgery. Treatment of established neuroma or nerve tether is notoriously difficult, and existing techniques have inconsistent outcomes, with patients often requiring multiple trips to the theatre. The authors present a novel technique for neuroma and scar tether prevention using an adipofascial flap accompanied by patient examples of our experience using this approach as an adjunct during the primary SRN repair, creating a gliding, interposing layer to prevent subsequent nerve traction pain and symptomatic neuroma. We identified five patients presenting with dorsal wrist injuries involving the SRN and one or more tendons. Patients' follow-up duration was a mean of 3.5 months (one to eight months). All follow-up patients showed no symptoms of a neuroma or nerve tether pain. All patients were discharged without re-referral or further surgery. Our patient sample demonstrates promising results using an adipofascial interposition flap as a prophylactic measure in traumatic injuries to reduce nerve tether pain and symptomatic neuroma formation in the SRN.

Biliary tree traumatic neuroma following laparoscopic cholecystectomy: A case report and literature review

Laparoscopic cholecystectomy has been found to be associated with the development of traumatic neuromas on rare occasions. The present study reports a rare case of post-cholecystectomy biliary tree traumatic neuroma. Herein, a 47-year-old female with a history of laparoscopic cholecystectomy presented with upper abdominal pain and anorexia. Upon an examination, a yellow discoloration of the sclera was observed. Magnetic resonance cholangiopancreatography revealed a dilated proximal bile duct and mild dilatation of the intrahepatic biliary tree due to a stricture. Intraoperatively, a hard bile duct mass was observed with multiple enlarged lymph nodes in the peri-hepatic region. The patient was initially suspected to have bile duct cancer; however, a histopathological analysis of the resected mass revealed a bile duct traumatic neuroma. Biliary traumatic neuromas may be underestimated since they often remain asymptomatic. It is unfortunate that, as traumatic neuromas often lack distinguishing characteristics, no particular radiological findings for traumatic neuromas of the bile duct have been described to date, at least to the best of our knowledge. The rarity of this condition, combined with the absence of a standardized diagnostic modality, renders its diagnosis difficult and can even lead to misdiagnosis as biliary cancer.

Nerve trunk healing and neuroma formation after nerve transection injury

The nerve trunk healing process of a transected peripheral nerve trunk is composed of angiogenesis, nerve fiber regeneration, and scarring. Nerve trunk healing and neuroma formation probably share identical molecular mediators and similar regulations. At the nerve transection site, angiogenesis is sufficient and necessary for nerve fiber regeneration. Angiogenesis and nerve fiber regeneration reveal a positive correlation in the early time. Scarring and nerve fiber regeneration show a negative correlation in the late phase. We hypothesize that anti-angiogenesis suppresses neuromas. Subsequently, we provide potential protocols to test our hypothesis. Finally, we recommend employing anti-angiogenic small-molecule protein kinase inhibitors to investigate nerve transection injuries.

Preventive Effect of Local Lidocaine Administration on the Formation of Traumatic Neuroma

BACKGROUND

Traumatic neuroma is a common sequela of peripheral nerve injury or amputation, which often leads to severe neuropathic pain. The present study investigated the effect of local lidocaine administration on preventing the formation of traumatic neuroma.

METHODS

Forty-eight male Sprague-Dawley rats were randomly assigned to two groups. The lidocaine group underwent sciatic nerve transection, followed by an injection of lidocaine (0.5%) around the proximal of a severed sciatic nerve under ultrasound-guidance 2-7 days after neurectomy. In the control group, rats received an injection of saline following neurectomy. The autotomy score, mechanical allodynia, thermal hyperalgesia, histological assessment, expression of neuroma, and pain-related markers were detected.

RESULTS

Lidocaine treatment reduced the autotomy score and attenuated mechanical allodynia and thermal hyperalgesia. The mRNA expression of α-SMA, NGF, TNF-α, and IL-1β all significantly decreased in the lidocaine group in comparison to those in the saline control group. The histological results showed nerve fibers, demyelination, and collagen hyperplasia in the proximal nerve stump in the saline control group, which were significantly inhibited in the lidocaine group.

CONCLUSIONS

The present study demonstrated that local lidocaine administration could inhibit the formation of painful neuroma due to traumatic nerve injury.

Post-traumatic glomus tumor of the left anterior supraclavicular nerve: a case report

OBJECTIVES

Peripheral nerve glomus tumors are extremely rare and occur with typical symptoms of peripheral neuropathic pain. Clinicians hardly consider this entity when faced with the swelling of a peripheral nerve and the diagnosis is reached only with histological examination. Nerves of limbs are usually affected and the solid glomus tumor is the most frequent histological variant.

CASE DESCRIPTION

A 55-year-old man presented with a glomus tumor of the anterior supraclavicular nerve of the left cervical plexus, misdiagnosed clinically and radiologically as neuroma. Despite the preoperative suspicion and the intraoperative appearance, the histological examination revealed a glomus tumor with a prevalent muscular component, a glomangiomyoma. Once the tumor was removed, pain regressed completely.

CONCLUSIONS

Because of its rarity, pre-operative diagnosis of glomus tumors is still a challenge, especially when arising from peripheral nerves. In the presence of chronic localized neuroma-type pain and sensitivity, glomus tumors should be considered in the pool of differential diagnosis, even if the imaging is not conclusive.

Traumatic neuromas of peripheral nerves: Diagnosis, management and future perspectives

Traumatic neuromas are infrequent in clinical settings but are prevalent following trauma or surgery. A traumatic neuroma is not a true malignancy, rather, it is a hyperplastic, reparative nerve reaction after injury and typically manifests as a nodular mass. The most common clinical manifestations include painful hypersensitivity and the presence of a trigger point that causes neuralgic pain, which could seriously decrease the living standards of patients. While various studies are conducted aiming to improve current diagnosis and management strategies via the induction of emerging imaging tools and surgical or conservative treatment. However, researchers and clinicians have yet to reach a consensus regarding traumatic neuromas. In this review, we aim to start with the possible underlying mechanisms of traumatic neuromas, elaborate on the diagnosis, treatment, and prevention schemes, and discuss the current experiment models and advances in research for the future management of traumatic neuromas.

Extradigital Glomus Tumor Mimics an Intrinsic Nerve Tumor in a Trauma Patient: Case Report and Literature Review

Glomus tumors are rare, painful, and usually benign neoplasms that typically occur at the subungual aspect of digits. Rarely, glomus tumors may arise in other areas of the body. We present a case of an extradigital glomus tumor on a forearm with prior trauma that presented with symptoms of an isolated peripheral neuropathy. Our review of literature reveals how upper or lower extremity glomus tumors can mimic neuropathies secondary to intrinsic nerve tumors (schwannoma, neurofibroma, or neuroma), radiculopathies, or manifestations of a complex regional pain syndrome (CRPS). We emphasize the need to consider a broad differential diagnosis that includes glomus tumor when evaluating patients with painful dermal masses producing peripheral neuropathy or radiculopathy signs owing to the infiltrative growth pattern into or mass effect exerted on nearby nerves.

Bilateral intraoral traumatic neuroma: Case report of a diagnostic challenge

Oral traumatic neuromas (TrNs) are relatively rare lesions and they originate from a damaged nerve. They present a diagnostic challenge, due to the complex clinical features that may mimic odontogenic, musculoskeletal, and other neuropathic pain conditions. We describe an interesting and challenging case of painful bilateral intraoral lesions in a 56-year-old South Indian female patient who presented with clinical features consistent with TrN lesions bilaterally, in relation to different branches of the trigeminal nerve. The patient had undergone numerous aggressive dental treatments and interventions over the past three decades, with little or no pain relief. Topical treatment with lidocaine gel utilizing a custom-made neurosensory stent rendered the patient significant and sustained pain relief.

Aligned nanofiber nerve conduits inhibit alpha smooth muscle actin expression and collagen proliferation by suppressing TGF-β1/SMAD signaling in traumatic neuromas

Transforming growth factor-beta 1 (TGF-β1) is a powerful activator of connective tissue synthesis that is strongly associated with the pathophysiology of traumatic neuroma. Previous studies have demonstrated that aligned nanofiber conduits made from silk fibroin and poly (L-lactic acid-co-ε-caprolactone; PLCL) could prevent traumatic neuromas. In the present study, the possible mechanisms of conduits in treating traumatic neuromas were investigated to provide theoretical basis for procedures. Aligned nanofiber conduits were used for nerve capping. Sciatic nerves of Sprague-Dawley rats were used to create an animal model. The present study contains two parts, each including four experimental groups. SB-431542/SRI-011381 hydrochloride was used to suppress/enhance TGF-β1/SMAD signaling. Part I discussed the connections between traumatic neuroma and the proliferation of alpha smooth muscle actin (α-SMA) and collagen; it also investigated the therapeutic effect of conduits. Part II hypothesized that conduits suppressed TGF-β1/SMAD signaling. Histological characteristics, quantitative analysis of α-SMA, collagens and signaling-related parameters were assessed and compared among groups one month postoperatively. Results from Part I demonstrated that aligned nanofiber conduits suppressed the expression of α-SMA and collagens; and results from Part II revealed the downregulation of pathway-related proteins, suggesting that the suppression was mediated by TGF-β1/SMAD signaling. Aligned nanofiber conduits may be effective nerve capping biomaterials. One of the mechanisms involves suppressing TGF-β1/SMAD signaling. Novel treatments using aligned nanofiber conduits could be developed to manage traumatic neuromas.

Palisaded encapsulated neuroma in tongue - A commonly misdiagnosed peripheral nerve sheath tumor

Palisaded encapsulated (solitary circumscribed) neuromas are benign neural tumors, rarely found in oral mucosa. This case reports a 24-year-old man that presented a unique soft nodule at the left side of the tongue. An excisional biopsy was performed under local anesthesia and histopathological examination of the surgical specimen revealed a well circumscribed mass composed of spindled Schwann cells, often aligned and fasciculated, forming occasional nodules embedded in a fibrous stroma. Histopathological analysis showed the presence of positive cells for S-100, EMA, CD57, and collagen IV. Based on clinical and microscopical features, the diagnosis established was of palisaded encapsulated neuroma. This case report aims to discuss the differential diagnosis among palisaded encapsulated neuroma and the other neural tumors that affect the oral mucosa.

Covering the proximal nerve stump with chondroitin sulfate proteoglycans prevents traumatic painful neuroma formation by blocking axon regeneration after neurotomy in Sprague Dawley rats

OBJECTIVE

Neuropathic pain caused by traumatic neuromas is an extremely intractable clinical problem. Disorderly scar tissue accumulation and irregular and immature axon regeneration around the injury site mainly contribute to traumatic painful neuroma formation. Therefore, successfully preventing traumatic painful neuroma formation requires the effective inhibition of irregular axon regeneration and disorderly accumulation of scar tissue. Considering that chondroitin sulfate proteoglycans (CSPGs) can act on the growth cone and effectively inhibit axon regeneration, the authors designed and manufactured a CSPG-gelatin blocker to regulate the CSPGs' spatial distribution artificially and applied it in a rat model after sciatic nerve neurectomy to evaluate its effects in preventing traumatic painful neuroma formation.

METHODS

Sixty female Sprague Dawley rats were randomly divided into three groups (positive group: no covering; blank group: covering with gelatin blocker; and CSPG group: covering with the CSPG-gelatin blocker). Pain-related factors were evaluated 2 and 8 weeks postoperatively (n = 30). Neuroma growth, autotomy behavior, and histological features of the neuromas were assessed 8 weeks postoperatively (n = 30).

RESULTS

Eight weeks postoperatively, typical bulb-shaped neuromas did not form in the CSPG group, and autotomy behavior was obviously better in the CSPG group (p < 0.01) than in the other two groups. Also, in the CSPG group the regenerated axons showed a lower density and more regular and improved myelination (p < 0.01). Additionally, the distribution and density of collagenous fibers and the expression of α-smooth muscle actin were significantly lower in the CSPG group than in the positive group (p < 0.01). Regarding pain-related factors, c-fos, substance P, interleukin (IL)-17, and IL-1β levels were significantly lower in the CSPG group than those in the positive and blank groups 2 weeks postoperatively (p < 0.05), while substance P and IL-17 remained lower in the CSPG group 8 weeks postoperatively (p < 0.05).

CONCLUSIONS

The authors found that CSPGs loaded in a gelatin blocker can prevent traumatic neuroma formation and effectively relieve pain symptoms after sciatic nerve neurotomy by blocking irregular axon regeneration and disorderly collagenous fiber accumulation in the proximal nerve stump. These results indicate that covering the proximal nerve stump with CSPGs may be a new and promising strategy to prevent traumatic painful neuroma formation in the clinical setting.

Painful Traumatic Neuromas in Subcutaneous Fat: Visibility and Morphologic Features With Ultrasound

OBJECTIVES

Subcutaneous neuromas usually result from trauma and may lead to dissatisfaction in patients with a trigger point, loss of sensitivity in the relevant territory of innervation, and spontaneous neuropathic pain. Confirming clinically suspected cases of neuroma may prove difficult. The objective of this study was to evaluate the visibility and morphologic features of traumatic subcutaneous neuromas of the limbs with ultrasound (US).

METHODS

Between January 2012 and August 2016, 38 consecutive patients clinically suspected of having subcutaneous neuromas were investigated with US. The diagnosis was confirmed on the basis of a focal morphologic abnormality of the nerve associated with trigger pain. Each neuroma was classified into 1 of 3 subtypes based on its injury pattern. The subtypes were terminal neuroma, spindle neuroma, and scar encasement, either isolated or associated with these subtypes.

RESULTS

Forty-four lesions were found in the 38 patients, including 29 spindle neuromas (65.9%), 14 terminal neuromas (31.8%) and 1 scar encasement with no nerve caliber abnormality (2.3%). Fifteen neuromas (35% of all neuromas) were associated with scar encasement. In 13 cases that required surgery, the diagnosis of neuroma or scar encasement could be surgically proven and confirmed the validity of the US findings.

CONCLUSIONS

Ultrasound can be used to show and classify subcutaneous nerves of the upper and lower limbs with high accuracy. The US trigger sign provides an indication of neuroma involvement in pain. This modality can play a substantial role both in the preoperative planning of neuroma surgery and in therapeutic US-guided procedures.

Traumatic neuroma in mastectomy scar: Two case reports and review of the literature

RATIONALE

Traumatic neuroma is a reparative proliferative response of the nerve after trauma or surgery, which rarely occurs in the breast. However, it must be distinguished from tumor recurrence.

PATIENT CONCERNS

A 78-year-old woman underwent left-sided modified radical mastectomy for invasive carcinoma, 7 years before this case. Two painless nodules near the mastectomy scar were discovered in regular follow-up physical examination. A 62-year-old woman had received right-sided modified radical mastectomy for intraductal carcinoma, 4 years before this case. An asymptomatic nodule near the mastectomy scar was detected during follow-up ultrasound (US) examination.

DIAGNOSIS

The lesions in both patients were diagnosed as traumatic neuroma.

INTERVENTIONS

The first patient underwent excisional biopsy. The second patient underwent US guided core-needle aspiration, followed by conservative therapy.

OUTCOMES

Neither patient complained of any discomfort, nor both exhibited normal physical and US findings during follow-up examinations.

LESSONS

Newly discovered nodules with the benign imaging features near the mastectomy site of a patient, especially with the tail sign, traumatic neuromas should be taken into consideration. Routine US examination is important for follow-up of breast cancer patients who have undergone mastectomy.

Expansile Traumatic Neuroma of the Intratemporal Facial Nerve

Objectives  To present a rare case of traumatic facial neuroma involving the geniculate ganglion and review relevant literature.

Patient  Thirty-year-old man.

Intervention  Microsurgical resection via combined mastoid-middle fossa approach with great auricular nerve interpositional graft.

Main Outcome Measures  Patient demographics and pre- and postoperative facial nerve function.

Results  A 30-year-old man with a reported history of prior Bell's palsy developed progressive complete (House–Brackmann VI) right facial paralysis following blunt trauma. Imaging was strongly suggestive of a geniculate ganglion hemangioma. As the patient had no spontaneous improvement in his poor facial function over the course of 9 months, he underwent resection of the facial nerve lesion with great auricular nerve graft interposition via a combined mastoid-middle fossa approach. Histopathology demonstrated disorganized fascicles, with axonal clustering reminiscent of sprouting/regeneration following trauma. No cellular proliferation or vascular malformation was present.

Conclusion  Traumatic facial nerve neuromas can occur following temporal bone trauma and can closely mimic primary facial nerve tumors. Akin to the management of geniculate ganglion hemangioma and schwannoma, preoperative facial function largely dictates if and when surgery should be pursued.

Asymptomatic Pinkish-Red Nodule over the Posterolateral Tongue

A young otherwise healthy male presented with asymptomatic pinkish-red nodule over postero-lateral tongue with the suspicion of having developed oral cancer. Biopsy from the lesion showed multiple circumscribed nodules in the lamina propria comprised of numerous oval and spindle-shaped cells. Abundant lymphatic tissue with germinal centres were also observed. Differentials included mucosal neuroma, traumatic neuroma, subgemmal neurogenous plaque, neurofibroma, and lingual tonsils. This quiz discusses the diagnosis and approach to the differential diagnoses in such a clinical setting.

Orbital rhabdomyosarcoma and traumatic neuroma following enucleation for a uveal schwannoma in a dog: a case report

A 4‐year‐old, female spayed Siberian husky with history of a uveal schwannoma presented for orbital swelling 9 months after enucleation. A second, malignant tumor developed in the same orbit. Therefore, uveal schwannomas may warrant early surgical intervention in the dog.

Histopathological Characterization of Tail Injury and Traumatic Neuroma Development after Tail Docking in Piglets

Tail docking of neonatal pigs is widely used as a measure to reduce the incidence of tail biting, a complex management problem in the pig industry. Concerns exist over the long-term consequences of tail docking for possible tail stump pain sensitivity due to the development of traumatic neuromas in injured peripheral nerves. Tail stumps were obtained post mortem from four female pigs at each of 1, 4, 8 and 16 weeks following tail amputation (approximately two-thirds removed) by a gas-heated docking iron on post natal day 3. Tissues were processed routinely for histopathological examination. Non-neural inflammatory and reparative epidermal and dermal changes associated with tissue thickening and healing were observed 1 to 4 months after docking. Mild neutrophilic inflammation was present in some cases, although this and other degenerative and non-neural reparative changes are not likely to have caused pain. Traumatic neuroma and neuromatous tissue development was not observed 1 week after tail docking, but was evident 1 month after tail docking. Over time there was marked nerve sheath and axonal proliferation leading to the formation of neuromata, which were either localized and circumscribed or comprised of multiple axons dispersed within granulation tissue. Four months after tail resection, neuroma formation was still incomplete, with possible implications for sensitivity of the tail stump.

Imaging Features Associated With Posttraumatic Breast Neuromas

OBJECTIVE

The aim of this study is to review the clinical and imaging features of patients with a histopathologic diagnosis of posttraumatic breast neuromas.

MATERIALS AND METHODS

We report eight biopsy-proven posttraumatic neuromas in six patients with a history of breast surgery. Mammographic, sonographic, and breast MRI examinations were reviewed according to the BI-RADS lexicon. In addition, the tail sign, a specific sign known to be associated with neuromas in other parts of the body, was assessed.

RESULTS

Mammographic, MRI, and sonographic examinations were performed in three, four and all six patients, respectively. The neuromas were occult on the three mammograms performed but all of them were identified on ultrasound as hypoechoic masses with parallel orientation; seven of the eight neuromas (87.5%) had an oval shape with circumscribed margins. Strain elastography performed for two patients (three neuromas) showed benign features (benign elasticity scores and fat-to-lesion ratio). Half of the masses showed a tail sign (focal thickening of the nerve adjacent to posttraumatic neuroma, similar to the dural tail sign). Of five lesions investigated by MRI, two were occult on MRI. The remaining three were visible as isointense foci on T1-weighted images, with a benign type 1 enhancement curve.

CONCLUSION

In patients who underwent breast surgery, a mass with benign features raises the possibility of a neuroma. Although the tail sign was present in half of the posttraumatic neuromas, imaging-guided biopsy remains the standard of care.