ABCDE of a pigmented caruncular lesion

Case

A 59-year-old Caucasian woman was referred for a pigmented lesion in the left medial canthus that was present for approximately 2 years. The lesion had become darker with central elevation in the past 6 months. A photograph shows areas of dark pigment extending over the medial one-third of the upper and lower lids as well as the caruncle. She is a one package a day smoker. But she had no known medical problems and had no surgery in the past.

The vision was 20/20 in each eye and the rest of the ocular exam was normal.

Next step

The next step would be:

1. Send a consult to the medical oncology service

2. Do a CT scan of the chest and abdomen

3. Biopsy of the lesion

4. Do complete blood work including melanoma tumor markers

Findings

Histopathological analysis reveals a malignant process harboring atypical pigmented cells with high nuclei to cytoplasmic ratio encompassing the whole thickness of the epithelium. Subepithelial clusters of heavily pigmented cells and transitioning to nevoid cells with nuclear pseudo-inclusion and then to individual fusiform cells deeper in the dermis were observed; a nesting-maturation pattern characteristic to nevi. The immunohistochemical panel shows diffuse MART1-MelanA positivity, whereas HMB-45 revealed superficial positivity and low immunoreactivity in the deep portion of the lesion, confirming the presence of a subepithelial nevus. The malignant cells, confined to the epithelium, were also positive for MART1-MelanA and HMB-45.

Diagnosis

Melanoma in-situ arising from a nevus

Correct answer

C – Biopsy of the lesion

Discussion

Malignant melanoma or melanoma in situ of the eyelid or canthus is a rare disease that represents less than 1% of all skin melanomas [Fig. 1]. To evaluate pigmented lesions of the eyelid, the ABCDE guidelines for skin melanocytic lesions are applicable (A: asymmetry, B: Border, C: color, D: diameter, E: evolution).[1,2] A biopsy is required for suspicious lesion. In this case, a melanoma was diagnosed, and the lesions are suspected to have arisen from a preexisting nevus that became darker and thicker (ABCDE). The patient will require wide excision of the lesion with clear margins either with frozen section or Mohs micrographic surgery followed by eyelid reconstruction. In this particular case, Mohs micrographic surgery was the chosen approach. A close follow-up is necessary to detect any recurrence of the lesion.

Figure 1.

(a) Clinical image showing areas of dark pigment extending over the medial one third of the upper and lower lids as well as the caruncle. (b) Low magnification image of the biopsy sample showing subepithelial clusters of pigmented cells transitioning to less pigmented, uniform nevoid cells in the deep dermis. (c) MART1-MelanA immunohistochemistry showing the melanocytic nature of the lesions. (d) HMB-45 immunohistochemistry showing strong positivity in the epithelium and low immunoreactivity in the deep portion of the lesion. (e) Higher magnification of the mid-deep portion of the lesion showing typical nevoid cells with intranuclear pseudoinclusions (arrowheads). (f) High magnification of the epithelial and subepithelial space, revealing melanocytic proliferation with high nuclei to cytoplasm ratio and atypia, replacing the whole epithelial thickness, consistent with melanoma in situ

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.