Merkel Cell Carcinoma
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Introduction[edit | edit source]
Merkel Cell Carcinoma (MCC) is a rare and aggressive skin cancer typically seen on the facial skin and extremities of elderly Caucasians and immunocompromised people. This neuroendocrine carcinoma accounts for less than 1% of all cutaneous malignancies and is associated with UV exposure and infection with the Merkel cell polyomavirus (MCPyV).[1][2][3]
Epidemiology[edit | edit source]
The worldwide incidence of MCC varies from 0.1 to 1.6 cases per 100,000 people annually with Australia recording the highest rate ranging from 0.82 to 2.5 [1][3][4]. It is then followed by New Zealand (0.88–0.96)[5][6] and United States (0.66–0.79)[1][7][8]. European countries such as France, Spain and Scotland report relatively similar incidence rates of 0.25 to 0.35 while Scandinavian countries have less incidence rates: 0.19 in Sweden and 0.12 in Finland. [1]
Risk factors of MCC[edit | edit source]
Predisposing factors for MCC are as follows:[1]
- Old age. The median age at diagnosis is documented to be 77 years with the highest incidence observed among people over 85 years old.
- UV exposure
- White skin type
- Male sex. The male-to-female ratio of MCC is over 2.5 incidence is over 2.5 in all reported studies.
- Immunosuppression. Approximately 6–12% of all patients with MCC are immunosuppressed.
Mechanism of Injury / Pathological Process[edit | edit source]
add text here relating to the mechanism of injury and/or pathology of the condition
Clinical Presentation[edit | edit source]
The most common sites of MCC are the sun-exposed areas of head and neck (29–43.9%) and the extremities (36.9–45%), whereas less than 5–10% of MCCs develop on partially sun-protected areas (abdomen, thighs and hair-bearing scalp) or highly sun-protected areas (buttocks). Extra-cutaneous sites are rarely affected. [1]
Clinically, MCC is manifested by a rapidly growing, painless, erythematous/violaceous nodule or plaque.[9]
AEIOU acronym for MCC clinical features:[10]
- A = asymptomatic
- E = expanding rapidly
- I = immune suppression
- O = older than50 years of age
- U=UV-exposed site.
Diagnostic Procedures[edit | edit source]
MCC is frequently misdiagnosed initially which can lead to delay in diagnosis. It may be confused with an inflammatory lesion such as acne or other folliculitis or with a benign tumour such as epidermal cyst, lipoma, dermatofibroma, fibroma and angioma. In many other cases, MCC is misinterpreted as another malignant tumour, mainly basal or squamous cell carcinoma and less frequently lymphoma, metastatic carcinoma, nodular or amelanotic melanoma or sarcoma. [1]
A clinically useful recommendation is that any nodule with non-specific morphology, lack of tenderness and fast-growing should be biopsied rather than monitored.
Physical examination[edit | edit source]
- Assessment of the primary tumour and documentation by light photography, palpation of regional lymph node basins, and inspection of the entire skin surface by a dermatologist.[2]
Dermatoscopy[edit | edit source]
Dermatoscopic images of MCC reveals:[1]
- Predominant red colour corresponding either to numerous vessels or generalised erythema
- Milky-red or pink structureless colour. It might be seen either as a pink background or as smaller roundish areas (milky red areas or globules or clods).
- Several morphologic types of vessels may be present, including dotted, glomerular, arborising and linear irregular vessels. Usually, more than one morphologic type of vessel co-exist, resulting in the so-called polymorphous vascular pattern, although lesions with monomorphous vessels have also been described.
- White areas are also frequently described.
Outcome Measures[edit | edit source]
add links to outcome measures here (see Outcome Measures Database)
Management / Interventions
[edit | edit source]
add text here relating to management approaches to the condition
Differential Diagnosis[edit | edit source]
Differential Diagnosis of MCC:[3]
- non-neuroendocrine small cell undifferentiated carcinoma
- small cell melanoma
- cutaneous lymphoma
- small round cell undifferentiated sarcoma
Resources
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add appropriate resources here
References[edit | edit source]
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 Gauci ML, Aristei C, Becker JC, Blom A, Bataille V, Dreno B, Del Marmol V, Forsea AM, Fargnoli MC, Grob JJ, Gomes F. Diagnosis and treatment of Merkel cell carcinoma: European consensus-based interdisciplinary guideline–Update 2022. European Journal of Cancer. 2022 Aug 1;171:203-31.
- ↑ 2.0 2.1 Zwijnenburg EM, Lubeek SF, Werner JE, Amir AL, Weijs WL, Takes RP, Pegge SA, van Herpen CM, Adema GJ, Kaanders JH. Merkel cell carcinoma: New trends. Cancers. 2021 Mar 31;13(7):1614.
- ↑ 3.0 3.1 3.2 Walsh NM, Cerroni L. Merkel cell carcinoma: A review. Journal of Cutaneous Pathology. 2021 Mar;48(3):411-21.
- ↑ Garbutcheon-Singh K, Curchin D, McCormack C, Smith S. Trends in the incidence of merkel cell carcinoma in Victoria between 1986 and 2016. InAUSTRALASIAN JOURNAL OF DERMATOLOGY 2019 May 1 (Vol. 60, pp. 40-40). 111 RIVER ST, HOBOKEN 07030-5774, NJ USA: WILEY.
- ↑ Lee Y, Chao P, Coomarasamy C, Mathy JA. Epidemiology and survival of Merkel cell carcinoma in New Zealand: a population‐based study between 2000 and 2015 with international comparison. Australasian Journal of Dermatology. 2019 Nov;60(4):e284-91.
- ↑ Robertson JP, Liang ES, Martin RC. Epidemiology of Merkel cell carcinoma in New Zealand: a population‐based study. British Journal of Dermatology. 2015 Sep 1;173(3):835-7.
- ↑ Fitzgerald TL, Dennis S, Kachare SD, Vohra NA, Wong JH, Zervos EE. Dramatic increase in the incidence and mortality from Merkel cell carcinoma in the United States. The American surgeon. 2015 Aug;81(8):802-6.
- ↑ Paulson KG, Park SY, Vandeven NA, Lachance K, Thomas H, Chapuis AG, Harms KL, Thompson JA, Bhatia S, Stang A, Nghiem P. Merkel cell carcinoma: Current US incidence and projected increases based on changing demographics. Journal of the American Academy of Dermatology. 2018 Mar 1;78(3):457-63.
- ↑ Becker JC, Stang A, DeCaprio JA, Cerroni L, Lebbé C, Veness M, Nghiem P. Merkel cell carcinoma. Nature reviews Disease primers. 2017 Oct 26;3(1):1-7.
- ↑ Heath M, Jaimes N, Lemos B, Mostaghimi A, Wang LC, Peñas PF, Nghiem P. Clinical characteristics of Merkel cell carcinoma at diagnosis in 195 patients: the AEIOU features. Journal of the American Academy of Dermatology. 2008 Mar 1;58(3):375-81.
