case_images: PMC9780374_01
case_images: 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.
case_images: fimmu-13-944810-g001.jpg
case_images: PMC9780374_01_fimmu-13-944810-g001.jpg
case_images: f1
case_images: 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 ).
case_images: 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).
case_images: fimmu-13-944810-g002.jpg
case_images: PMC9780374_01_fimmu-13-944810-g002.jpg
case_images: f2
case_images: In immunohistochemical staining, the histiocytic cells are S100+, CD31+, CD68+, CD163+, CD14+, Fascine+, CD31+, CD1a-, and Langherine- ( Figure 2 ).
case_images: Immunohistochemical staining for cyclin D1 (A, B) and OCT2 (C, D).
case_images: fimmu-13-944810-g003.jpg
case_images: PMC9780374_01_fimmu-13-944810-g003.jpg
case_images: f3
case_images: According to Ravidrant et al., OCT2 and cyclin D1 stain was performed and the lesional cells resulted positive for both antibodies ( Figure 3 ).