Reporting regression in primary cutaneous melanoma. Part 1: history, histological criteria and pathogenesis.

Regression is an important histopathological parameter reported for the diagnosis of primary cutaneous melanoma. Histological regression is defined by The College of American Pathologists as the replacement of tumour cells by lymphocytic inflammation, with attenuation of the epidermis, and nonlaminated dermal fibrosis with inflammatory cells, melanophagocytosis and telangiectasia. Histological regression may be reported as absent versus present and, if present, as complete, partial or segmental. The stages of histological regression are early, intermediate and late, depending on the extent of histological inflammation and fibrosis. Regression occurs when the host's immune system attacks primary melanocytic tumour cells via tumour-infiltrating lymphocytes, resulting in fibrosis. The immunological mechanisms driving complete, partial and segmental regression may vary. In this first part of this two-part review, we review the history, histological criteria and pathogenesis of regression in primary cutaneous melanoma, while in Part 2 we will review the effect of histological regression on prognosis, evaluation and management.

Reporting regression in primary cutaneous melanoma. Part 2: prognosis, evaluation and management.

The effect of histological regression on patient prognosis for primary cutaneous melanoma is controversial. Some authors hypothesize that regression indicates a robust systemic immune response and may decrease risk of metastasis. Others argue that histological regression calls into question a T0 diagnosis because there may have been an invasive component of the melanoma that is no longer visible but is still active. The literature to date does not suggest that histological regression is associated with increased risk of positive sentinel lymph node status, metastasis or increased risk of mortality. Thus, the presence of histological regression should not change patient staging, evaluation or management. The criteria used for reporting regression have varied dramatically across studies, and standardized reporting is needed to foster evidence-based practices in the future.

Acral melanoma foot lesions. Part 2: clinical presentation, diagnosis, and management.

Acral melanoma (AM) is a rare subtype of cutaneous malignant melanoma found on acral skin, primarily on the soles of the feet. Although rare, it is the most common subtype of melanoma found in patients of African or Asian ethnicity and has a poor prognosis, often because of the more advanced stage of presentation at diagnosis. In the second of this two-part series, we review the clinical presentation, histopathology, diagnosis and management of AM. Clinically, AM presents as a variegated lesion with blue-black pigment and irregular borders on acral skin. A parallel-ridge pattern is a very specific dermoscopic finding for AM. The differential diagnoses of AM include acral naevus, pyoderma gangrenosum, pyogenic granuloma, verrucous carcinoma and peripheral neuropathy-induced foot ulcers. If there is a clinical suspicion of AM, an excisional biopsy should be taken. Once diagnosis is confirmed by histology, surgical excision is the standard treatment. Overall, dermoscopy and histopathology are key tools in the diagnosis of AM. A greater emphasis on melanoma screening and awareness is essential in minority populations to improve survival outcomes in AM.

Acral melanoma foot lesions. Part 1: epidemiology, aetiology, and molecular pathology.

Acral melanoma (AM) is a rare subtype of cutaneous malignant melanoma (MM) found on acral skin, primarily on the soles of the feet. Although rare, it is the most common subtype of MM found in patients of African or East Asian ethnicity and has a poor prognosis, often because of the more advanced stage of presentation at diagnosis. The pathogenesis of AM is unclear, but genetic alterations, including mutations in BRAF, NRAS, and KIT have been implicated. Early diagnosis of AM is important for a better prognosis, but its identification is often challenging, leading to easy misdiagnosis. In the first of this two-part review, we review the history, epidemiology, aetiology and molecular pathology of AM; in part 2 we will review diagnosis and management.

Vitamins and cutaneous wound healing.

BACKGROUND: Vitamins have long been thought to modulate the various stages of wound healing through a variety of proposed mechanisms. Our goal was to investigate relevant studies examining the role of different vitamins in wound healing. METHODS: MEDLINE, Cochrane Database of Systematic Reviews, and Google Scholar were searched for basic science and clinical studies examining the role of vitamins as adjuncts in wound healing. RESULTS: Mechanisms of action for each of the vitamins are reviewed. It was suggested by many of the studies that the major vitamins A, C, E, D, K, and B have demonstrated utility as adjuncts in wound care in basic science and clinical trials. CONCLUSION: There is a vast amount of literature on the effect of vitamins on wound healing at the basic science level. Further understanding and controlled trials will help better understand how to utilize vitamins in wound care. DECLARATION OF INTEREST: None.

Trigeminal trophic syndrome.

Trigeminal trophic syndrome (TTS) is a rare cause of facial ulceration, which is believed to develop after insult to the trigeminal ganglia or other parts of the peripheral/central nervous system in the trigeminal pathway. The pathogenesis of TTS is poorly understood. Developing a better understanding of TTS will allow early recognition and improved treatment. Although the ulcers develop predominantly on the ala nasi, the literature on ulcer locations is limited. In this article, we review the epidemiologic aspects of TTS, expand on our knowledge of the anatomic location of the ulcers, and discuss current theories for its aetiology and briefly review the approaches to its management.

Naevus comedonicus: a spectrum of body involvement.

Naevus comedonicus (NC) is a rare developmental anomaly, with < 200 cases reported in the literature. It usually occurs on the face, neck or chest, appearing as groups of closely arranged dilated follicular openings with keratin plugs. Several associations have been made in the literature. We review the current literature, emphasizing the clinical features, associated conditions and therapeutic options.

Tunga penetrans: a stowaway from around the world.

Tungiasis is a cutaneous ectoparasitic infestation by the female sand flea Tunga penetrans. It is predominantly a health problem in sub-Saharan Africa, the Caribbean, Latin America and South America. However, increasing numbers of returning travellers, immigrants, and adopted children are also affected in non-tropical countries. It is a cause of substantial morbidity, with prevalence rates as high as 76% in certain endemic areas. To date, the early extraction of the flea is still the first line therapy.

Current treatment options in psoriasis.

Much has been learned about the pathophysiology of psoriasis during the last decade, and as a result, traditional treatments such as coal tar have been joined by immunosuppressive agents. Patients can be offered a variety of therapies keyed to the type and severity of disease.