Mulberry like growth in the right ear.

A 68 year old male agriculturist presented with asymptomatic growth over his right ear for the past three years. The growth was insidious in onset and started as a small firm pigmented papule three years back. The lesion was aymptomatic and gradually increased in size. He gives history of occasional bleeding on touch. No history of similar skin lesion in the past or in family members. No history of any type of ear trauma or ear surgery in the past. Examination revealed 3 × 4 cm, mulberry like pigmented growth [Figure 1], soft to firm in consistency, mobile with no tenderness on palpation seen in the groove between helix and anti-helix of right ear. Excission biopsy was done and histopathology of the tumor showed hyperkeratosis, parakeratosis, acanthosis and papillomatosis with sharp horizontal demarcation from the dermis. The epidermal cells are composed of squamous and basaloid cells with abundant melanin pigment and keratohyaline granules. Squamous eddies and several horncysts are seen [Figures 2 and 3]. Non-specific lymphocyitc inflammatory infiltrate was seen in upper dermis.

Figure 1

Mulberry like pigmented growth seen over right ear

Figure 2

Histopathology shows hyperkeratosis, parakeratosis, acanthosis, papillomatosis with multiple squamous eddies and horncysts seen. Dermis showing non-specific inflammatory infiltrate seen (H and E stain, 10×)

Figure 3

Higher magnification showing squamous eddies and horncysts (H and E stain, 40×)

Question

What is your diagnosis?

Answer

Synonym

Basosquamous cell acanthoma, Inflamed seborrhiec keratosis.

Asymptomatic pigmented growth in an elderly man in sun exposed area with histopathology showing squamous and basaloid cells with squamous eddies and several horncysts confirms the diagnosis irritated seborrheic keratosis.

Discussion

The seborrhiec keratoses (also known as “seborrhiec verruca”, “brown wart”, “basal cell papilloma” and “senile wart”) are noncancerous benign skin growth that originates from keratinocytes. They usually involve sun exposed areas like face, scalp, upper trunk, and upper limbs. Their morphology is varied and multiple. They begin as brown pigmented macules and develop gradually in to slightly raised, brown to black, oval or polypoidal papules with a ‘stuck-on’ appearance. The surface of the lesion can be uneven, verrucous, and dull. They may be pedunculated resembling skin tags, but with a rough surface. Clinical variants include dermatosis papulosa nigra, stucoo keratosis, and melanoacanthoma.

Etiology of seborrhiec keratosis is not known. There is a possible role of epidermal growth factors or its receptors in the development of seborrhiec keratosis.[12] BCL 2 (B cell lymphoma 2), an apoptosis suppressing oncogene, has a low expression in seborrhiec keratosis in contrast to high values seen in squamous and basal cell carcinoma.[3] A high frequency of mutations of tyrosene kinase receptor FGFR3 (fibroblast growth factor receptor 3) has been found in certain types of seborrhiec keratosis.[4-6] Mutations were identified in 39% of seborrhies kearatosis. Chronic exposure to sun is the main etiological factor in the development of seborrhiec keratoses. Generalized and eruptive presentation is associated with malignant conditions like gastrointestinal malignanacy, breast carcinoma, lymphoma, leukemia, and melanoma. It may also be associated with palmoplantar keratoderma, and acanthosis nigricans.

There are many histological types of seborrhiec keratoses which are seen like most common acanthotic, adenoid, hyperkeratotic, irritated, clonal, melanoacanthoma, pigmented, and inverted follicular keratoses. Uncommonly, there may be bowenoid transformation or carcinoma in situ within the lesion and rarely, basal cell carcinoma may develop. In the irritated or activated type of seborrhiec keratoses, squamous cells outnumber basaloid cells, shows the presence of ‘squamous eddies’ (eosinophilic, flattened squamous cells arranged in ‘onion peel’ fashion) in the epidermis, resembling poorly differentiated horn pearls. These squamous eddies are differentated from the keratin pearls of squamous cell carcinoma by their small size, large number and well circumscribed configuration. Squamous cells are the predominated variant seen in epidermis. The pathogenesis of squamous eddies is the result of activation of resting basaloid cells into squamous cells. These squamous eddies are also seen in inverted follicular keratoses and follicular poroma.[78]

Konishi E et al, have reported irritated type of seborrhiec keratosis from right external ear canal in an elderly male.[9] Lee JP et al, reported a case of irritated seborrhiec keratosis from a previous incision site.[10]

A treatment option for seborrhiec keratosis includes simple curettage, cautery or cryotherapy. Often they tend to recur; patients should be advised regarding the benign nature of the condition with reassurance.