Figure 1
From: Renal cell carcinoma with novel VCL–ALK fusion: new representative of ALK-associated tumor spectrum
Pathology of six cases of pediatric renal cell carcinoma. (a) Case 1. Bivalved kidney showing an irregularly shaped 6.5-cm solid renal mass expanding to the collecting system and ureter with mild hydronephrosis. (b) Case 1. Hematoxylin and eosin (H&E) staining of a tumor with diffuse sheet-like growth of focally poorly adherent cells with large eosinophilic cytoplasm, intracytoplasmic lumina, mildly pleomorphic nuclei with open chromatin, small nucleoli, and occasional groves. Hemosiderosis and lymphoplasmacytic infiltrate are seen. (c) Case 1. Immunohistochemical analyses using anti-TFE3 antibody shows nuclear staining in tumor cells. (d) Case 2. H&E staining of the primary tumor shows diffuse growth of undifferentiated tumor cells with relatively small cytoplasm and round nuclei with prominent nucleoli. (e) Case 3. H&E staining of undifferentiated tumor cells shows small cytoplasm and large round nuclei with prominent nucleoli growing in sheet-like and cribriform patterns with intervening desmoplastic stroma. (f) Case 4. H&E staining shows eosinophilic and clear tumor cells with small uniform nuclei and papillary tumor architecture. (g) Case 5. H&E staining shows eosinophilic and clear tumor cells with large moderately polymorphic nuclei with open chromatin, small nucleoli, and papillary and acinar tumor architecture. (h) Case 6. H&E staining of predominantly clear tumor cells with mildly polymorphic nuclei with open chromatin, small nucleoli, and papillary and acinar tumor architecture with numerous psammoma bodies. Magnification (panels b–h) × 400.
