Pagetoid cells
|
100% |
Presence of large, nucleated cells in the epidermis, twice the size of keratinocytes, with dark nuclei and bright cytoplasm (shape not specified) |
Melanocytes in the suprabasal layers of the epidermis |
Polymorphic Pagetoid Cells
|
90% |
Presence of cells in the epidermis that are round and dendritic (variability of the aspect of pagetoid cells) |
Melanocytes in the suprabasal layers of the epidermis |
Round pagetoid cells
|
70% |
Presence of bright nucleated cells with dendritic processes in the epidermis (variability of the aspect of pagetoid cells) |
Melanocytes in the suprabasal layers of the epidermis |
Dendritic Cells
|
100%* |
Presence of nucleated and round cells with dark nucleus and bright cytoplasm in the epidermis (variability of the aspect of pagetoid cells) |
Melanocytes in the suprabasal layers of the epidermis |
Dark Pagetoid Cells
|
70% |
Presence of low refractivity cells characterized as dark structures similar to ‘‘holes’’ in the epidermis (variability of the aspect of pagetoid cells) |
Melanocytes in the suprabasal layers of the epidermis |
Atypical Cells
|
80% |
Presence of atypical/irregular cells in the epidermis without specifying the format |
Melanocytes in the suprabasal layers of the epidermis |
Dendritic Structures
|
80% |
Presence of dendrites in the epidermis - numerous interspersed bright lines originating from dendritic cells, with the cell body not always visible |
Dendritic projections of melanocytes or Langerhans cells in the epidermis |
Atypical cells infiltrating follicular structures
|
80% |
Infiltrating dendritic/round cells in the inner part of the hair follicle |
Infiltration of the hair follicle and adnexal structures by atypical melanocytes - aspect observed in melanomas of the lentigo maligna type |
Atypical Honeycomb Pattern/Architectural disorder of the epidermis
|
50%/50%
100%* for the use of both terms
|
Atypical keratinocytes or keratinocyte disarray |
Keratinocytes with variation in size and shape |
Epidermal Granularity
|
90% |
Presence of bright granular particles in the epidermis, similar to ‘‘dust’’ (‘‘speckled’’ appearance) |
Extracellular melanin granules in the epidermis |
Non-edged papillae
|
90% |
Irregular outline of dermal papillae with no rim of bright cells without bright cell edges |
Enlarged interpapillary spaces with the presence of large atypical melanocytes |
Non-visible dermal papillae
|
100%* |
Loss of papillary contour / papillary architecture or non visible dermal-epidermal transition |
Disordered proliferation of melanocytes determining alteration of the epidermal ridges (flattened epidermis) |
Large dendritic or round nucleated cells, in the DEJ
|
100%* |
Presence of atypical cells in the DEJ -large, bright, round or dendritic (>50 micrometers) nucleated cells with unusual outline
(triangular/star-shaped) or eccentric large nucleus
|
Proliferation of atypical melanocytes as solitary units in the DEJ |
Spindle Cells
|
90% |
Atypical cells with different shapes in the DEJ |
Proliferation of atypical melanocytes in the DEJ |
Focal increase of atypical melanocytes and nests
|
70% |
Presence of atypical cells in the DEJ with additional characteristics such as dense nests, sparse nests, bright cells of varying sizes, etc. |
Proliferation of atypical melanocytes or nests of atypical melanocytes in the DEJ |
Junctional nests
|
90% |
Presence of regular round junctional cellular aggregates |
Typical melanocyte nests in the DEJ |
Junctional Thickening
|
80% |
Presence of tubular/ elongated junctional aggregates |
Elongated junctional melanocyte nests |
‘‘mitochondria-like’’ structures
|
100% |
Dendritic cells that project from the epidermis towards the dermis forming ‘‘bridges’’ |
Structures observed in horizontal histopathological sections: increased atypical melanocytes around the dermal papillae, projecting towards the center of the dermal papillae forming ‘‘bridges’’1111 Braga JC, Macedo MP, Pinto C, Duprat J, Begnami MD, Pellacani G, et al. Learning reflectance confocal microscopy of melanocytic skin lesions through histopathologic transversal sections. PLoS One. 2013;8:e81205.
|
Short Interconnections
|
100% |
Junctional thickening and nests around the papillae |
Elongated nests of junctional melanocytes that can form ‘‘bridges’’ between interpapillary ridges |
Presence of a large amount of bright cells in the DEJ (dendritic and/or round nucleated cells): sheet of cells
|
80% |
Proliferation of cells in the DEJ, distributed on the same plane, in a non-aggregated form, and with blurring of dermal papillae |
Lentiginous proliferation of atypical melanocytes in the DEJ, mainly in melanomas in areas with sun damage |
Medusa head-like structures
|
90% |
Elongated structures that protrude from hair follicles - distributed around the entire follicle perimeter |
|
Nucleated round cells in the dermis
|
100%* |
Presence of solitary melanocytes in the papillary dermis - rounded/oval with well-defined bright cytoplasm and central dark nucleus |
Presence of atypical melanocytes in the papillary dermis |
Dense nests
|
70% |
Presence of cohesive nests of melanocytes in the papillary dermis -well-defined, compact aggregates of monomorphic cells with easily identified individual edges |
Nests of round/oval junctional or dermal melanocytes |
Dense and sparse nests
|
70% |
Presence of irregular/disconnected nests of melanocytes in the papillary dermis |
Nests of atypical melanocytes |
Cerebriform nest
|
80% |
Presence of ‘‘cerebriform’’ aggregates in the dermis |
Nodular aggregates of atypical melanocytes in melanomas with a dermal component |
Melanophages
|
100%* |
Irregularly-shaped bright cells with poorly-defined edges and usually no visible nucleus |
Melanophages in the papillary dermis |
Bright dots / Bright particles
|
50%/50%
100%* for the use of both terms
|
Small bright particles in the dermis |
Inflammatory cells in the dermis, other than melanophages |
Irregular vessels/ Numerous vessels of increased caliber
|
50%/50%
100%* for the use of both terms
|
Presence of prominent vessels in the papillary dermis |
Dilated and increased vascularity in the superficial dermis |
Ringed pattern
|
70% |
Papillae with edges well demarcated by the presence of bright cells, forming ‘‘rings’’ |
Presence of junctional melanocytes arranged side by side or in small nes |
Meshwork pattern
|
100% |
Enlarged interpapillary spaces, predominantly consisting of junctional thickening and/or non-edged papillae |
Irregular proliferation of junctional nests of melanocytes, forming bridges between epidermal ridges |
Clod pattern
|
100% |
Predominance of dense and compact melanocyte nests or aggregates in the superficial dermis |
Proliferation of melanocyte nests in the dermis |
Mixed pattern
|
100% |
Combination of 2 or more patterns seen in melanocytic neoplasms with a junctional and a dermal component |
|
Non specific pattern
|
80% |
Loss of recognizable pattern in the DEJ, usually associated with melanocytic proliferations with abrupt or imprecise epidermal/dermal transition |
|
Asymmetry
|
70% |
The distribution of structures seen on confocal microscopy is different in the two halves of the lesion |
Does not apply |
Nests at the periphery of the lesion
|
90% |
Presence of junctional or dermal nests distributed around the periphery of the lesion |
|
Sharp border cutoff
|
70% |
Precise demarcation between the edge of the lesion and the skin at the periphery, a pattern often seen in Spitz nevi |
Does not apply |