Menzies Method

From dermoscopedia

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Introduction:

The Menzies Method is a simplified dermoscopyDermoscopy is a non invasive diagnostic method. method for diagnosing melanomas [1]. In the original series it had a sensitivity of 92% and a specificity of 71% for the diagnosisis the identification of the nature and cause of a certain phenomenon. Diagnosis is used in many different disciplines with variations in the use of logic, analytics, and experience to determine "cause and effect". In systems engineering and computer science, it is typically used to determine the causes of symptoms, mitigations, and solutions of melanomaThis glossary term has not yet been described.. Subsequent to this it has been repeatedly shown to have the highest sensitivity for the diagnosis of melanoma (incorporating both invasive and in situThis glossary term has not yet been described. lesions) compared to other published methods [2][3][4][5][6] It has also been shown to improve the sensitivity for the diagnosis of small diameter melanoma [7]. The Menzies method is based on 11 features which are scored as present or absent. This reduces the intra- and interobserver errors. This algorithmIn mathematics and computer science, an algorithm (Listeni/ˈælɡərɪðəm/ AL-gə-ri-dhəm) is a self-contained sequence of actions to be performed. Algorithms can perform calculation, data processing and automated reasoning tasks. has been shown to enable primary care physicians to increase their sensitivity for the diagnosis of melanoma by 38% compared with standard clinical visualization. It was developed based on a training set of 62 invasive melanomas and 159 clinically atypical pigmented nonmelanomas were scored for 72 surface microscopic features. Unlike in some other methods, the nonmelanoma set included nonmelanocyticThis glossary term has not yet been described. lesions, such as seborrheic keratosesThis glossary term has not yet been described., hemangiomas, and dermatofibromas. To create the model, individual features were selected with low sensitivity (0%) for melanoma, defining the two “negative features” for melanoma, and high specificity (>85%) for melanoma, defining the 9 “positive features.” This diagnostic method was tested on an independent set comprising 45 invasive melanomas (median Breslow thickness <0.7 mm) and 119 atypical nonmelanomas. The model gave a sensitivity of 92% and specifi city of 71% for invasive melanoma. It should be emphasized that most of the nonmelanomas used to determine specificity were clinically atypical, leading to the decision to perform a biopsy. The use of the model would have avoided excision of 71% of those lesions. Clearly, the true specificity of the method in the field is likely to be much greater. the method

This medthod uses so called “negativeThis glossary term has not yet been described.” and “positive” features. For a melanoma to be diagnosed, none of the two “negative features” should be found and at least 1 of the 9 “positive features” must be present.

Negative Features (both features must be absent):

Symmetry of Pigmentation Pattern

This is symmetry of all pattern structures, including colorColor (American English) or colour (Commonwealth English) is the characteristic of human visual perception described through color categories, with names such as red, yellow, purple, or blue. along any axis through the center (of gravity) of a lesion. It does not require symmetry of shape. The presence of symmetry of the pigmentation pattern is often the immediate defining feature of benignis any condition that is harmless in the long run pigmented lesions.


Single ColorColor (American English) or colour (Commonwealth English) is the characteristic of human visual perception described through color categories, with names such as red, yellow, purple, or blue.

The colors scored are black, gray, blue, red, dark brown, and tan. White is not scored. A single color excludes the diagnosis of melanoma. Melanomas usually manifest more than one color because malignantThis glossary term has not yet been described. melanocytes often retain cellular melanin and can be found at varying depths in the skinThis glossary term has not yet been described.. Melanin at the level of the stratum corneum appears black and at the level of the midepidermis it appears dark brown. Both black and dark brown colors are often seen in melanoma with pagetoid invasion of the epidermis. Melanin at the dermoepidermal junction (DEJ) appears as tan, melanin in the upper dermis as gray, and melanin in the middermis as blue. In summary, most melanomas are asymmetric and have more than one color.

Positive Features (at least one feature must be found ):



Menszies Method schematic.jpg


Blue-White Veil

This is an irregular confluent blue pigmentation with an overlying “ground glass” white film or “veil”. Histologically it represents melanin in the middermis (melanoma cells, dense collections of melanophages, or free melanin) with compact orthokeratosis of the overlying epidermis. It cannot be associated with red-blue lacunaeThis glossary term has not yet been described. found in hemangiomas or well-defined structures, such as large ovoid nests seen in pigmented basal cell carcinomas. It can never occupy the entire lesion, as occurs with many blue neviThis glossary term has not yet been described.. Blue-white veil is found in 51% of invasive melanoma and has a specificity of 97%.


Multiple Brown DotsDots are small, round structures of less than 0.1 mm in diameter that have a red color when corresponding to blood vessels; however, when due to melanin, their color ranges from black, brown, to blue-gray depending on the depth and concentration of the melanin in the skin (Tyndall effect).

These are focal aggregations of dark brown dotsDots are small, round structures of less than 0.1 mm in diameter that have a red color when corresponding to blood vessels; however, when due to melanin, their color ranges from black, brown, to blue-gray depending on the depth and concentration of the melanin in the skin (Tyndall effect)., which histopathologically represent intraepidermal (suprabasal) melanoma cells. They have to be distinguished by their small size (dots rather than globulesThis glossary term has not yet been described.) and should be multiple and focal rather than scattered sparsely. They are found in 30% of melanoma and have a specificity of 97%.


PseudopodsBulbous and often kinked projections seen at the lesion edge, either directly associated with a network or solid tumor border.

These are bulbous “foot-like” projections present at the edge of a lesion. They can arise from a pigmented network or from the border of a solid pigmented tumor. They are morphologically highly variable. They have the same histologic correlate as radial streamingRadial linear extensions at the lesion edge. Pseudopods are found in 23% of invasive melanoma and have a specificity of 97%. Pseudopods should never occupy a uniform circumferential position in melanoma, as seen in Spitz neviThis glossary term has not yet been described..


Radial streamingRadial linear extensions at the lesion edge,

Finger-like projections focally present at the edge of the lesion. These projections include linear extensions emanating from an existing network or, more often, they arise from a solid tumor. Histologically they represent confluent radial nests of melanoma at an intraepidermal or DEJ position, which is classically seen in some superficialThis glossary term has not yet been described. spreadingThis glossary term has not yet been described. melanomas. Radial streaming is found in 18% of melanoma and has a 96% specificity.


Scar-like Depigmentation

The final phase of regressionThis glossary term has not yet been described. may be seen as scarring. Scar-like depigmentationArea of white that is whiter than surrounding normal skin (true scarring). It should not be confused with hypo- or depigmentation due to simple loss of melanin. Shiny white structures and blood vessels are not seen in areas of regression. is seen as well-defined areas that are pure white in color. It is seen in 36% of invasive melanomas and has a specificity of 93%. Scarlike depigmentation should be distinguished from hypomelanotic areas commonly found in nevi; the former’s pure white color and well-defined irregularly shaped borders helps in distinguishing it from benign hypopigmented areas.


Peripheral Black Dots/GlobulesThis glossary term has not yet been described.

These are found at or near the edge of the lesion. They are truly black in color in contrast to brown globules commonly found in benign lesions. They should also be distinguished from central black dots/ globules, which are found in some dysplastic neviThis glossary term has not yet been described.. They are found in 42% of invasive melanoma and have a specificity of 92%. Histologically they represent accumulation of pigment in the stratum corneum, arising from pagetoid spread of malignant melanocytes.


Multiple (Five to Six) Colors

In invasive melanoma melanin is often found at different levels from the stratum corneum to the middermis. Due to the melanin distribution in melanoma and due to the presence of increased vasculature in melanoma, most melanomas display multiple colors. To be a significant positive feature there must be at least five colors from a possible total of six (red, tan, dark brown, black, gray, and blue). Multiple (five to six) colors are found in 53% of invasive melanoma and have a specificity of 92%.


Multiple Blue-Gray Dots

In areas of regression of melanocyticThis glossary term has not yet been described. lesions, melanin-laden macrophages (melanophages) can be found in the acute phase. These are seen as partly aggregated blue-gray dots often described as “pepper-like” in morphologyThis glossary term has not yet been described. (Fig. 6d.15). When abundant, melanophages may form areas of bluewhite veil. Because regression is a common feature of superficial spreading melanoma, multiple blue-gray dots are found in 45% of invasive melanoma and have a specificity of 91%. They are also a common feature of lentigo maligna (in situ melanoma).


Broadened Network

This is an increase in the width of the “grids” or “cords” of the pigmented net found in melanocytic lesions. This broadening of the network is usually found focally in melanoma, rather than uniformly throughout the lesion. It is found in 35% of invasive melanoma with a specificity of 86%. Broadened network is also a common feature of lentigo malignaThis glossary term has not yet been described.. It correlates histologically with expansion of melanocytic nests found at the dermo-epidermal junction (DEJ).

Menzies method gives a sensitivity of 92% and specificity of 71% for the diagnosis of melanoma.



Menzies method schematics 2.jpg


Summary:

A lesion is suspicious of melanoma if it has more than one color and is asymmetric in pattern. Suspect lesions displaying any of the 9 positive features for melanoma are considered to be melanoma unless proved otherwise. The positive feature for melanoma are: blue-white veil multiple brown dots focal pseudopodsBulbous and often kinked projections seen at the lesion edge, either directly associated with a network or solid tumor border. focal radial streaming scar-like depigmentationArea of white that is whiter than surrounding normal skin (true scarring). It should not be confused with hypo- or depigmentation due to simple loss of melanin. Shiny white structures and blood vessels are not seen in areas of regression. peripheral black dots/globules five to six colors multiple blue-gray dots/peppering focally broadened networkwidening of the network lines



References:
  1. Menzies et al.: Frequency and morphologic characteristics of invasive melanomas lacking specific surface microscopic features. Arch Dermatol 1996;132:1178-82. PMID: 8859028.
  2. Argenziano et al.: Dermoscopy of pigmented skin lesions: results of a consensus meeting via the Internet. J. Am. Acad. Dermatol. 2003;48:679-93. PMID: 12734496. DOI.
  3. Blum et al.: Digital image analysis for diagnosis of cutaneous melanoma. Development of a highly effective computer algorithm based on analysis of 837 melanocytic lesions. Br. J. Dermatol. 2004;151:1029-38. PMID: 15541081. DOI.
  4. Dolianitis et al.: Comparative performance of 4 dermoscopic algorithms by nonexperts for the diagnosis of melanocytic lesions. Arch Dermatol 2005;141:1008-14. PMID: 16103330. DOI.
  5. Henning et al.: CASH algorithm for dermoscopy revisited. Arch Dermatol 2008;144:554-5. PMID: 18427058. DOI.
  6. Carrera et al.: Validity and Reliability of Dermoscopic Criteria Used to Differentiate Nevi From Melanoma: A Web-Based International Dermoscopy Society Study. JAMA Dermatol 2016;152:798-806. PMID: 27074267. DOI.
  7. Bono et al.: Micro-melanoma detection: a clinical study on 206 consecutive cases of pigmented skin lesions with a diameter < or = 3 mm. Br. J. Dermatol. 2006;155:570-3. PMID: 16911283. DOI.