Fig. 2From: Hypermetabolic lymphadenopathy following the administration of COVID-19 vaccine and immunotherapy in a lung cancer patient: a case reportPreauricular lymph node tissue obtained by ultrasound-guided core needle biopsy. Hematoxylin and eosin staining (200Ă—) reveals poorly differentiated carcinoma (a). Immunohistochemical studies show malignant cells are diffusely and strongly positive for cytokeratin 7 (b)Back to article page