Whithers 1

Whithers 2

Whithers 3

Desmomela

BWEEMS

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MDMLMM

Nevoid MDM

MDMhalo

Nearneoplasia

MDMhalo, metastasizing

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Pictorial 1

Pictorial 2

Pictorial 3

Pictorial 4

C7P4-1: To the right side of the field, a portion of lymph node is partially preserved. To the left of the center of the field, an expansile tumor has displaced the normal nodal architecture. The lesion is outlined by a condensation of fibrous tissue.

C7P4-2: Large tumor cells are arranged in sheets and in closely spaced, poorly defined fascicles. The cells have pale, amphophilic cytoplasm and plump nuclei with marginated chromatin and prominent nucleoli. The green arrow points to an atypical mitotic figure.

C7P4-3: An area of degeneration is represented in the upper part of the field. In this area, cells are loosely spaced in a loosely fibrillated, fibrous matrix. The green arrows point to a large, melanogenic tumor cell. Some of the neighboring cells form thin fascicles that contribute a neuroid quality. There are spotty infiltrates of lymphocytes and plasma cells. There are also extracellular pigment deposits.

C7P4-4: With an immunoreaction for HMB45, some of the tumor cells are positive. This would appear to correspond to the area that showed degenerative changes on the H&E stained section. In the same general area, rare tumor cells contained melanin in their cytoplasm. See C4P7-3.

C7P4-5: The tumor cells are uniformly immunoreactive for S-100 protein. Some of the cells have a dendritic quality.