PMC9780374_01
At hematoxylin and eosin (H&E), inguinal lymph node presented an almost normal architecture with a marked expansion of the sinuses occupied by a histiocytic element proliferation. The histiocytic elements appeared voluminous, with a round nucleus and vesicular chromatin, evident but not prominent nucleoli, and abundant eosinophilic cytoplasm. The follicles show aspects of activation and involution and appear depleted in lymphocytes.
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f1
The histiocytic elements appeared voluminous, with a rounded nucleus, open, vesicular chromatin, evident but not prominent nucleoli, and abundant eosinophilic clear cytoplasm frequently containing vacuoles with intact inflammatory cells (emperipolesis) ( Figure 1 ).
On immunohistochemical staining, the histiocytic cells are S100+, CD31+, CD68+, CD163+, CD14+, Fascine+, CD34 nonspecific, CD1a- and Langherine-. (A, C: 5x magnification; B, D: 10 x magnification).
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f2
In immunohistochemical staining, the histiocytic cells are S100+, CD31+, CD68+, CD163+, CD14+, Fascine+, CD31+, CD1a-, and Langherine- ( Figure 2 ).
Immunohistochemical staining for cyclin D1 (A, B) and OCT2 (C, D).
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f3
According to Ravidrant et al., OCT2 and cyclin D1 stain was performed and the lesional cells resulted positive for both antibodies ( Figure 3 ).