Seborrheic keratosis of the nasal tip-an unusual case report

Seborrheic keratosis is a benign tumour of skin, a common hyperkeratotic lesion of the epidermis,that usually occurs in the trunk and less frequently in the extremities, face and the scalp. A 65-year old farmer presented with a long standing, slowly growing, firm, redbrown, polypoidal mass about 2×2.5 cm in size, located at the skin mucosa interfare of the tip of nose. The lesion was excised under general anesthesia and histopathologic examination showed seborrheic keratosis. Diagnosis is made on the basis of clinical & histopathological examination. Here, we discuss the clinical presentation, differential diagnosis, pathological diagnosis and management of such a case. There was no recurrence during a year follow-up.


Introduction
Seborrheic keratosis is a common hyperkeratotic lesion of the epidermis that usually appears in the mid-life or older age.The trunk is the most common site, but lesions may also be found on the extremities, face and the scalp [1][2][3] .Seborrheic keratosis (seborrheic wart, senile wart) is usually small and multiple.But large solitary lesions are very rare.Men and women are affected equally and most patients have multiple lesions that are often distributed symmetrically 3 .
The exact cause of seborrheic keratosis is unknown 3, 4. Predisposing factors are ageing, physical trauma, irritation, infection and host response [4][5] .Seborrheic keratosis should be included in the differential diagnosis of nasal lesions, but this fact has not been made adequately clear in the otolaryngologic literature 6 .We will report a case in which a large solitary lesion affected the tip of nose.

Case Report
A 65-year old,male,farmer from a village in Jamalpur, for the last 12 years, has suffered from a blackish mass on the tip of nose, which has gradually increased in size.There were no other associated symptoms, such as pain or itching.On local examination there was a single, firm, blackish mass with a warty surface of 2× 2.5 cm in size was present on the tip of nose.The mass was pedunculated and with a broad base.

Fig-1: Bloody discharge & central ulceration of nasal growth with maggots.
Mass was sent for histopathological examination, report of which revealed seborrheic keratosis .Haematoxylin -Eosin stained sections showed basal cells of normal epidermis with variable amount of melanin pigment.The marked keratosis with keratin filled cyst and invagination of keratin in mass are suggestive of seborrheic keratosis .

Discussion
Seborrheic keratoses are flat, verrucous, polypoid or pedunculated lesions that measure generally 0.5 cm to 1 cm and vary in color, from tan-brown to black.The majority of the lesions are asymptomatic and have a well-circumscribed border 7 .The Leser-Trélat sign is the sudden onset of seborrheic keratoses or an increase in the number of lesions and may be associated with an underlying internal malignancy, usually adenocarcinoma of the stomach, colon or breast 3 .The clinical differential diagnosis It was not tender.It was centraly ulcerated and bloody discharge due to maggots' formation with well defined margin and no other site involvement of body.Other otorhinolaryngologic examination was within normal limits.Excisional biopsy under general anaesthesia was done with full thickness skin graft from right supraclavicular region.Based on all these findings, the diagnosis was made as seborrheic keratosis with an inverted growth pattern.

Figt-2,3: After excision of nasal growth
Due to good glycemic control, the post operative healing was adequate with the approximation of margins.Pt was followed in the immediate post operative period of 3,6,12 months.The course was uneventful.includes acrochordon, verruca vulgaris, follicular adnexal tumors, melanocytic tumors, and squamous or basal cell carcinoma 2,8,9 .Therefore, histopathologic examination is critical to confirm clinical presentation.Removal of seborrheic keratosis may be necessary because of cosmetic choices or for associated symptoms such as pruritus, bleeding, inflammation or confirmation of clinical impression.Treatment options are cryosurgery, electrodesiccation, shave excision, carbon dioxide laser vaporization or surgical removal.Topical steroids can be used for irritated lesions for symptomatic relief 2,10 .Surgical removals should be reserved for lesions that are suspicious for malignancy.To our knowledge, seborrheic keratosis occurring in the nasal tip has not been reported previously in the literature.Clinicians should be aware of such unusual location of this lesion.