case_images: PMC11066175_01
case_images: Imaging of a patient with systemic manifestation of ALK-positive Histiocytosis. (A) Magnetic resonance imaging (T1-weighted imaging) displays a cauliflower-like soft tissue mass measuring approximately 2.0cm x 2.1cm x 1.9cm, exhibiting clear margins situated at the posterior lower wall of the bladder. (B) Magnetic resonance imaging (T2-weighted imaging) illustrates numerous small nodular lesions within both testes, revealing fatty suppression on T2WI and measuring approximately 0.8cm in diameter. (C) Multiple nodular distributions lacking capsules are observed under low magnification, scattered within the testicular parenchyma, displaying relatively clear boundaries of the nodules. (D) Lesions resemble xanthoma-like structures with the proliferation of foam-like tissue cells characterized by large cell volumes, irregularly folded or lobulated nuclei, and fine nuclear chromatin. (E) Immunohistochemical examination of the testicular mass displays positivity for ALK1 (cytoplasmic positivity). (F) Fluorescence In Situ Hybridization testing was conducted on the testicular and bladder masses, revealing ALK1 gene rearrangement.
case_images: fonc-14-1366766-g001.jpg
case_images: PMC11066175_01_fonc-14-1366766-g001.jpg
case_images: f1
case_images: MRI examination indicated a cauliflower-like soft tissue mass, about 2.0cm x 2.1cm x 1.9cm in size, with clear margins, located at the bladder's posterior lower wall (bladder neck) ( Figure 1A ). T2WI, measuring about 0.8cm in diameter, and hydrocele in the bilateral scrotum ( Figure 1B ). Small nucleoli were visible with fine chromatin, without significant cellular atypia, rare mitotic figures, and interstitial infiltration of lymphocytes, plasma cells, and histiocytes ( Figures 1C, D ).