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

Traumatic Neuroma in the External Auditory Canal

Traumatic neuroma is the reparative proliferation of axons and Schwann cells at the proximal end of a severed nerve following injury or surgery. Traumatic neuromas with or without clinical symptoms have rarely been reported in the external auditory canal. A 50-year-old woman with a history of trauma visited our otorhinolaryngology clinic with a 7 × 5-mm mass localized on the anterior wall of the external auditory canal. The mass was easily removed via surgical excision and was histopathologically diagnosed as a neuroma. No signs of recurrence were observed after excision. Herein, the authors present this case, along with a review of the literature.

Mechanosensitive Ion Channel TMEM63A Gangs Up with Local Macrophages to Modulate Chronic Post-amputation Pain

Post-amputation pain causes great suffering to amputees, but still no effective drugs are available due to its elusive mechanisms. Our previous clinical studies found that surgical removal or radiofrequency treatment of the neuroma at the axotomized nerve stump effectively relieves the phantom pain afflicting patients after amputation. This indicated an essential role of the residual nerve stump in the formation of chronic post-amputation pain (CPAP). However, the molecular mechanism by which the residual nerve stump or neuroma is involved and regulates CPAP is still a mystery. In this study, we found that nociceptors expressed the mechanosensitive ion channel TMEM63A and macrophages infiltrated into the dorsal root ganglion (DRG) neurons worked synergistically to promote CPAP. Histology and qRT-PCR showed that TMEM63A was mainly expressed in mechanical pain-producing non-peptidergic nociceptors in the DRG, and the expression of TMEM63A increased significantly both in the neuroma from amputated patients and the DRG in a mouse model of tibial nerve transfer (TNT). Behavioral tests showed that the mechanical, heat, and cold sensitivity were not affected in the Tmem63a^-/- mice in the naïve state, suggesting the basal pain was not affected. In the inflammatory and post-amputation state, the mechanical allodynia but not the heat hyperalgesia or cold allodynia was significantly decreased in Tmem63a^-/- mice. Further study showed that there was severe neuronal injury and macrophage infiltration in the DRG, tibial nerve, residual stump, and the neuroma-like structure of the TNT mouse model, Consistent with this, expression of the pro-inflammatory cytokines TNF-α, IL-6, and IL-1β all increased dramatically in the DRG. Interestingly, the deletion of Tmem63a significantly reduced the macrophage infiltration in the DRG but not in the tibial nerve stump. Furthermore, the ablation of macrophages significantly reduced both the expression of Tmem63a and the mechanical allodynia in the TNT mouse model, indicating an interaction between nociceptors and macrophages, and that these two factors gang up together to regulate the formation of CPAP. This provides a new insight into the mechanisms underlying CPAP and potential drug targets its treatment.

Trigeminal Traumatic Neuroma: a Comprehensive Review of the Literature Based On a Rare Case

PURPOSE OF REVIEW

Traumatic neuromas in general, and trigeminal traumatic neuromas in particular, are relatively rare entities originating from a damage to a corresponding nerve or its branches. This manuscript is a comprehensive review of the literature on trigeminal traumatic neuromas based on an interesting and challenging case of bilateral intraoral lesions.

RECENT FINDINGS

The diagnosis for this patient was bilateral trigeminal traumatic neuromas. It is possible that these patients have a genetic predisposition to the development of these lesions. It is a neuropathic pain condition and may mimic dental and other trigeminal pain entities. Topical treatment with lidocaine gel, utilizing a custom-made neurosensory stent, rendered the patient significant and sustained pain relief. Trigeminal traumatic neuromas present a diagnostic challenge even to a seasoned clinician, due to the complex clinical features that may mimic other entities. Topical medications such as local anesthetics may be a good viable alternative to systemic medications to manage the pain associated with the condition. Early identification of the lesion and the associated pain helps in the succinct management of symptomatic trigeminal traumatic neuromas.

Traumatic neuroma at the mastectomy site, unusual benign lesion, mimicking tumor recurrence: A report of two cases

Traumatic neuroma is not a true neoplasm but a reparative proliferation of axons, Schwann cells, and fibroblasts at the proximal end of transected or injured nerves resulting from trauma or surgery. Breast traumatic neuroma after breast surgery, with or without clinical symptoms, has rarely been reported. Once found, it should be differentiated from tumor recurrence, and tissue confirmation is necessary, although it is small in size and demonstrates a benign appearance in imaging studies. Herein, we present two cases of traumatic neuroma at the mastectomy site. They were incidentally encountered during ultrasound evaluation of mastectomy beds given concerns for potential recurrence or malignancy, and pathologic confirmation by ultrasound-guided core needle biopsy was sufficient for the diagnosis.