Menzies Method

From dermoscopedia

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Introduction:[edit]

The Menzies Method is a simplified dermoscopy method for diagnosing melanomas [1]. In the original series it had a sensitivity of 92% and a specificity of 71% for the diagnosis of melanoma. Subsequent to this it has been repeatedly shown to have the highest sensitivity for the diagnosis of melanoma (incorporating both invasive and in situ 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 algorithm 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 nonmelanocytic lesions, such as seborrheic keratoses, 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 “negative” 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):[edit]

Symmetry of Pigmentation Pattern[edit]

This is symmetry of all pattern structures, including color 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 benign pigmented lesions.

Single Color[edit]

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 malignant melanocytes often retain cellular melanin and can be found at varying depths in the skin. 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 ):[edit]



Menszies Method schematic.jpg



Blue-White Veil[edit]

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 lacunae 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 nevi. Blue-white veil is found in 51% of invasive melanoma and has a specificity of 97%.

Multiple Brown Dots[edit]

These are focal aggregations of dark brown dots, which histopathologically represent intraepidermal (suprabasal) melanoma cells. They have to be distinguished by their small size (dots rather than globules) and should be multiple and focal rather than scattered sparsely. They are found in 30% of melanoma and have a specificity of 97%.

Pseudopods[edit]

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 streaming. 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 nevi.

Radial streaming,[edit]

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 superficial spreading melanomas. Radial streaming is found in 18% of melanoma and has a 96% specificity.

Scar-like Depigmentation[edit]

The final phase of regression may be seen as scarring. Scar-like depigmentation 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/Globules[edit]

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 nevi. 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[edit]

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[edit]

In areas of regression of melanocytic 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 morphology (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[edit]

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 maligna. 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:[edit]

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 pseudopods focal radial streaming scar-like depigmentation peripheral black dots/globules five to six colors multiple blue-gray dots/peppering focally broadened network



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.