Malignant melanoma developing in an area of palmoplantar keratoderma (Greither's disease)

The tumor genetics of acral melanoma: What should a dermatologist know?

Dermatologists stand at the gateway of individualization of classification, treatment, and outcomes of acral melanoma patients. The acral melanoma genetic landscape differs in vital ways from that of other cutaneous melanomas. These differences have important implications in understanding pathogenesis, treatment, and prognosis. The selection of molecularly targeted therapy must be adapted for acral melanoma. It is also critical to recognize that tumor development is far more complex than an isolated event, reliably treated by a medication acting on a single target. Tumors exhibit intratumor genetic heterogeneity, metastasis may have different genetic or epigenetic features than primary tumors, and tumor resistance may develop because of the activation of alternative genetic pathways. Microenvironmental, immune, and epigenetic events contribute and sustain tumors in complex ways. Treatment strategies with multiple targets are required to effectively disrupt the tumor ecosystem. This review attempts to translate the current molecular understanding of acral melanoma into digestible concepts relevant to the practice of dermatology. The focus is tumor genetics defining potentially treatable cancer pathways, contextualized within the relevant pathologic and molecular features.

[Acral melanoma in a patient with hereditary keratoderma of the palms and soles (mal de Meleda): A chance association?]

INTRODUCTION

Development of acral malignant melanoma in Mal de Meleda is highly unusual. As far as we could ascertain, to date, only 10 previous cases have been published. Herein, we report a new case.

OBSERVATION

A 64-year-old Algerian man was followed for familial Mal de Meleda. The diagnosis was based on clinical presentation as he had a non-syndromic hereditary foul-smelling and yellowish palmoplantar keratoderma transgrediens. After the failure of acitretin, which had not prevented retractile and mutilating progression of the palmoplantar keratoderma, he had undergone surgery with graft excision of both palms. At the age of 59 years, he presented a tumor on the dorsal aspect of the 1^st phalanx of the 3^rd finger of the right hand in a non-grafted area. The diagnosis of acral melanoma was confirmed histologically. The radiological findings showed a specific homolateral axillary adenopathy. He underwent digital amputation of the 3^rd finger, with lymph node dissection and chemotherapy involving dacarbazine. Follow-up at 5 years showed complete remission of the melanoma.

DISCUSSION

Mal de Meleda is a hereditary palmoplantar keratoderma due to mutation of the SLURP1 gene. Clinical diagnosis is based on the typical phenotype in adulthood. The occurrence of acral melanoma, which is a rare form of melanoma (1 to 7%), especially in the fingers, together with an unusual palmoplantar keratoderma in a subject of type IV phototype does not appear to be a chance event. This association seems to be the outcome of immune dysregulation rather than of chronic inflammation.

Olmsted Syndrome—Palmoplantar and Periorificial Keratodermas: Association with Malignant Melanoma

Background:

Olmsted syndrome is a rare congenital disorder with mutilating palmoplantar keratoderma, periorificial keratotic plaques, and other variable features.

Objective:

We describe a 65-year-old woman with Olmsted syndrome complicated by the occurrence of a malignant melanoma inside the plantar keratoderma. To our knowledge, this is the first reported case of such an occurrence in Olmsted syndrome. The published cases of this rare disorder are reviewed.

Conclusion:

An association between malignant epithelial tumors and Olmsted syndrome has already been reported. The association of malignant melanoma with other types of palmoplantar keratodermas has been reported. This may suggest a predisposition to melanocytic as well as squamous cell malignancies in congenital keratodermas. Oral retinoids appear to be the most promising treatment for Olmsted syndrome and for other symptomatic keratodermas.

Genital melanocytic nevus arising in a background of lichen sclerosus in a 7-year-old female: the diagnostic pitfall with malignant melanoma. A literature review

Genital melanocytic nevus represents a distinct form of melanocytic proliferation, which can exhibit significant atypia, both clinically and histologically. In a background of lichen sclerosus (LS), the histologic changes could be misconstrued as indicative of malignant melanoma. We present herein a case of the atypical genital nevus of childhood complicated by LS, and a review of the literature is performed. Tissue was available for routine light microscopy and immunohistochemical evaluation to assess the expression of soluble adenylyl cyclase. Fluorescent in situ hybridization studies were conducted to assess for abnormalities in Myb1, CCND1, RREB1 and CEP6. The specimen showed an atypical compound melanocytic proliferation arising in a background of LS. The lesion exhibited significant architectural atypia based on the high-density confluent nature of the junctional melanocytic proliferation with epidermal effacement, rare areas of pagetoid ascent, and the heavily pigmented epithelioid quality of the melanocytes. Fluorescent in situ hybridization studies were normal. The soluble adenylyl cyclase antibody preparation demonstrated a benign nevus-like pattern. The lesion was felt to represent an atypical genital melanocytic nevus, which can resemble a partially regressed melanoma in a background of LS. It is very important for the pathologist to be aware of this entity to avoid misdiagnosis.

Acral Malignant Melanoma and Striated Palmoplantar Keratoderma (Brunauer-Fohs-Siemens Syndrome): A Fortuitous Association?

BACKGROUND

Striated palmoplantar keratoderma or Brunauer-Fohs-Siemens syndrome is a very rare, focal, nonepidermolytic palmoplantar keratoderma with autosomal inheritance. Unlike other palmoplantar keratodermas, no association with visceral or skin cancer has ever been reported.

OBJECTIVE

We report a case of malignant melanoma arising in the hyperkeratotic lesions on the right heel of a patient with striated palmoplantar keratoderma. The lesion was completely excised; our patient also underwent sentinel lymph node biopsy and then was treated with high-dose interferon adjuvant therapy.

METHODS

Sentinel lymph node biopsy incision was made in elliptical fashion, long enough to harvest a full-thickness skin graft to cover the wide local excision defect. The skin graft was defatted by sharp dissection. Several perforations were made in graft and it was secured in place with sutures and bolster dressing.

RESULTS

At follow-up, the grafted skin showed hyperkeratotic changes but no local or systemic signs of the disease was observed.

CONCLUSION

The association between striated palmoplantar keratoderma and acral melanoma is discussed.

Malignant melanoma developing in an area of hereditary palmoplantar keratoderma (Mal de Meleda)

Palmoplantar keratoderma (PPK) refers to a genetically heterogeneous group of skin diseases, which may be inherited in autosomal dominant or recessive fashion. We observed a case of a 74-year-old man with Mal de Meleda, who developed malignant melanoma inside the hyperkeratotic palmar skin of the right hand. Many authors have reported a higher incidence of cancer in cases affected by palmoplantar hyperkeratosis both for hereditary association and particularly for mechanical damage of the affected areas. The association with melanoma has already been described, but not in a true Mal de Meleda type syndrome as in the case reported in this paper.