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MDMHALO

MDMLMM

NEVOIDMDM

MDMhalo, metastasizing

Near-neoplasia

General Index

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PICTORIAL 1

PICTORIAL 2

PICTORIAL 3

PICTORIAL 4

P4-1: Near a margin of the problem lesion, a lentiginous and junctional component is represented. In some nests, the spindle cells of the junctional component are loosely attached to their neighbors. These qualities might be cited as Spitz nevus-like and from this observation, the observer might be led to a parcel of virtual images relevant to the interpretation of Spitz nevus. The two fascicles in the dermis (green arrows) are better characterized as dermal defects containing epithelioid nevus-like cells and lymphocytes. These dermal components are interpreted as zones of cytolysis mediated by the lymphoid infiltrates of the halo nevus-like phenomena; in these areas, pigmented, small nevus cells have undergone cytolysis and the epithelioid cells (a neoplastic descendant of the small cells) have survived. If the pattern of this field were pure without the more significant dermal component as seen in other fields at a lower magnification, the lesion would qualify as ATYPICAL HALO NEVUS.

P4-2: In this field, clusters of epithelioid cells are in intimate contact with nests of pigmented, small nevus cells (red arrows). The pigmented, small nevus cells are representative of a common cytologic variation often encountered in the setting of classic halo nevi. The epithelioid cells (green arrows) are almost as common but have not been as adequately documented as a cytologic variation in the setting of classic, common halo nevus. The lytic defects (blue arrows) are interpreted as the site in which the lymphocytes of the halo nevus-like phenomena have induced cytolysis of packets of pigmented, small nevus cells.  The green, open arrow head near the center of this field points to an epithelioid cell that is outlined by lymphocytes. This cluster of cells form a “rosette” of cell mediated immunity.

P4-3: The sclerosis of a senescent halo nevus-like reaction is represented. In this example, the epithelioid cells focally have survived in the area of sclerosis. The epithelioid cells are individually outlined by a thickened basement membrane in nevus cell-like patterns (type C-like patterns). Some of the epithelioid cells have prominent central nucleoli. Blue arrows outline a rounded nest of small, nevus-like cells.

P4- 4: Epithelioid cells surround irregular nests of pigmented, small nevus cells. It could be argued that the epithelioid cells issue from the nests of pigmented, small nevus cells and do so mostly at the peripheries of such nests. At the bottom of the field, there are lytic defects containing lymphocytes and histiocytes (i.e., markers for halo nevus-like phenomena).