Neurofibroma of External Ear: The Updates.

Dear Editor,

I would like to resubmit this article for the kind consideration for publication in your esteemed journal. I am happy to inform you that I have thoroughly gone through the literature to address the issues raised by the reviewers with evidences. I give a point wise reply to the reviewers’ comments.

Which histopathologic variant is common among external ear neurofibroma (NF)?

Of three histopathological types, that is, localized, plexiform, and diffuse;[1] diffuse variant involves skin and subcutaneous tissues of head neck region.[23456 Among head neck region, periauricular area is the most common site.[1] So diffuse variant is common among external ear NF.

How long the patients need follow-up?

Follow-up is mainly to identify an early recurrence in operated cases. If we are planning observation only, wait and watch at regular intervals with radiological evaluation and radical excision if there is an evidence of tumor growth.[7]

As we know that diffuse NFs recur frequently.[8] Follow-up should depend on the age of the patient, extent and location of tumor, and partial or complete excision status.

We can expect a less recurrence and hence increase the follow-up duration when there is a gross total resection and low residual tumor volume.[9] Proper counseling regarding early follow-up is needed, if there is rapidly enlarging mass, neurogenic pain/motor weakness, or disfiguring.[10]

Literature does not mention the exact duration for follow-up. van Zuuren and Posma[2] advised yearly follow-up in their article.

Is magnetic resonance imaging (MRI) necessary in all these patients?

Imaging is done to know the characteristic, extent, and deeper extension of a soft tissue lesion. Although NFs are superficial lesions, which can be evaluated clinically, but it is always better to carry out radiology before histopathological confirmation. Ultrasonography (USG) and computed tomography (CT) can assess the nature but cannot demarcate between the vascularity of the lesion. USG has the advantages of no radiation exposure, cost-effectiveness, and early reports; it also carries limitations of not assessing the extent and depth of larger lesions. CT can help to know the extent when bony external auditory canal starts getting involved.

MRI is the investigation of choice as it demarcates the tumor with the surrounding structures; it also differentiates between all three varieties, that is, local, plexiform, and diffuse. USG and CT scans are less reliable as diffuse NF resembles lipoma or hemangioma.[11]

If MRI suggests a highly vascular lesion, consider a preoperative angiogram, and if necessary, a preoperative intra-arterial embolization, if hemorrhage is anticipated.[12]

Therefore, in resourceful settings, we should consider MRI as a necessary investigation in these patients.

What are the long-term complications of surgery in these patients?

The long-term complications of surgery are recurrence, hypertrophic scarring,[13] permanent neurological deficit, functional impairment, wound healing abnormalities,[1415] and rarely malignant transformation.[1617]

Age <10 years at surgery, head-neck-face-trunk lesion, and incomplete resection take shorter relapse time.[918]

Several authors advised for wide meatoplasty to prevent reobstruction.[19] We have a case that reports wide external auditory canal after 5.5-year follow-up.[20] Therefore, the major concerns to be kept in mind during surgery are the extent of resection in balance to the likelihood of recurrence and loss of function.

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