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| Year : 2017 | Volume
: 4
| Issue : 1 | Page : 54-55 |
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Hyperpigmented plaque on the sole
Anupam Das1, Dibyendu Basu2, Sunder R Rao3
1 Department of Dermatology, KPC Medical College and Hospital, Kolkata, West Bengal, India
2 Department of Dermatology, Medical College and Hospital, Kolkata, West Bengal, India
3 Dr. Rao’s Pathology and Biopsy Centre, Kanpur, Uttar Pradesh, India
| Date of Web Publication | 19-Jun-2017 |
Correspondence Address:
Anupam Das
Building - “PRERANA,” 19, Phoolbagan, Kolkata - 700 086, West Bengal
India
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/2349-5847.208300
How to cite this article:
Das A, Basu D, Rao SR. Hyperpigmented plaque on the sole. Pigment Int 2017;4:54-5 |
A 65-year-old woman presented with a jet-black colored lesion over her right sole, present for the preceding 5 years. To start with, it was a brown lesion, which gradually darkened and increased in size. A painful ulcer had developed over the lesion approximately 6 months back. The patient could not recall any history of trauma prior to the onset of the lesion. Cutaneous examination revealed a black scaly well-circumscribed plaque over lateral margin of the sole of right foot extending to the plantar aspect of the fourth digit (maximum diameter 5 cm). The ulcer was situated medial to the plaque. It was a superficial ulcer with granulation tissue in the floor [Figure 1]. All the peripheral pulses of right lower limb were palpable. Firm, non-tender mobile, and enlarged inguinal lymph nodes were present over the right side. Routine hematological, renal, and liver function tests, urine and stool examination, X-ray chest, and ultrasonographic examination of the abdomen were within normal limits, except Hb of 7 g/dl. Histopathology revealed irregular acanthosis with asymmetric proliferation of atypical melanocytes at the dermoepidermal junction. Melanin aggregates were present in the stratum corneum as well [Figure 2] and [Figure 3]. | Figure 1: Hyperpigmented plaque with ulceration on the right foot near the toes
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 | Figure 2: Photomicrograph showing irregular acanthosis with asymmetric proliferation of atypical melanocytes at the dermoepidermal junction (Hematoxylin and Eosin, 40×)
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 | Figure 3: Photomicrograph showing melanin aggregates in the stratum corneum (Hematoxylin and Eosin, 40×)
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| Diagnosis | |  |
The clinical scenario and the histopathology clinched the diagnosis of acral lentiginous melanoma. The patient had been referred to oncosurgery for management. The mass was completely excised. In addition, enbloc dissection of the inguinal lymph nodes was performed, and histology was suggestive of metastatic infiltration.
| Discussion | | |
Melanoma is very rare in the Asian population.[1] Acral lentiginous melanoma (ALM) is the most common histological subtype among Asian people. The etiology is uncertain, and unlike other subtypes, sun exposure is not a risk factor for ALM. The most common site of involvement is foot and the prognosis is grave.[2] The term lentiginous is used because majority of the lesional cells are single and located near the dermoepidermal junction. Various molecular markers are on the verge of development to assess the prognosis of ALM. Wide local excision with reconstruction is the primary management. In widespread cases, immunotherapy, biologics such as ipilimumab, BRAF inhibitors (vemurafenib and dabrafenib), and MEK inhibitors (trametinib) have been used. The frequency of BRAF mutation in ALM is lower than other types of melanoma; hence, the therapeutic targets may be different, although there are suggestions that ALM is also likely to be a target of BRAF (B-rapidly accelerated fibrosarcoma) kinase inhibitors due to the constitutively activated RAS (rat sarcoma)/RAF (rapidly accelerated fibrosarcoma)/MEK (mitogen activated protein kinase)/ERK (extracellular signal regulated kinase) pathways.[3] Malignant melanoma is an uncommon disease in India, and it carries a significant burden of morbidity on account of the delay in presentation and diagnosis. Hence, clinicians should remain vigilant in the suspicion of cases for timely management.[4]
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
| References | | |
| 1. | Lee HY, Chay WY, Tang MB, Chio MT, Tan SH. Melanoma: Differences between Asian and Caucasian patients. Ann Acad Med Singapore 2012;41:17-20.  [ PUBMED] |
| 2. | Nam KW, Bae YC, Nam SB, Kim JH, Kim HS, Choi YJ. Characteristics and treatment of cutaneous melanoma of the foot. Arch Plast Surg 2016;43:59-65. [ PUBMED] |
| 3. | Hong JW, Lee S, Kim DC, Kim KH, Song KH. Prognostic and clinicopathologic associations of BRAF mutation in primary acral lentiginous melanoma in Korean patients: A preliminary study. Ann Dermatol 2014;26:195-202. [ PUBMED] |
| 4. | Sharma K, Mohanti BK, Rath GK. Malignant melanoma: A retrospective series from a regional cancer center in India. J Can Res Ther 2009;5:173-80. [ PUBMED] [Full text] |
[Figure 1], [Figure 2], [Figure 3]
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