Congenital and under 6 months Under 5 years Mesoblastic nephroma Clear cell sarcoma Rhabdoid tumor Intrarenal neuroblastoma Ossifying renal tumor Older children, adolescents, young adults All pediatric age groups Translocation-associated…

Fig. 3.1 Reactive lymphadenopathy (Diff-Quik stain, medium power). This case of reactive lymphadenopathy shows a follicle-like organization, in which the lymphoid cells cluster together with tingible body macrophages. The lymphoid…

Fig. 4.1 Thyroid cyst fluid (Diff-Quik stain, high power). Hemosiderin-laden macrophages in a background of watery colloid. Note that hemosiderin stains deep blue with Diff-Quik stain. Fig. 4.2 Benign follicular/colloid…

Predominantly neutrophils Predominantly eosinophils Acute pneumonia (empyema) Acute peritonitis Fungal infection Mycobacterial infection Penetrating injury Perforated viscera or intrathoracic rupture of esophagus Neoplasm Mimic: Karyorrhectic debris from high-grade lymphomas or…

Fig. 10.1 Common findings of normal and contaminated CSF. (a) Gross appearance of CSF. Normal (left) and blood-diluted (right) cerebrospinal fluid. (b) (Wright-Giemsa stain, high power). Normal CSF. Normal CSF…

Artifacts Preparation artifacts Preservation, fixation, and/or staining artifacts Smearing or cytospin artifacts Degenerative changes Air and/or water bubbles Procedure-related artifacts Dilution with blood and/or bone marrow Crush artifact Obscuring necrotic…

Location Main differential diagnosis Liver Infection  Cysts  Vascular lesions  Mesenchymal neoplasms  Focal nodular hyperplasia  Hepatic adenoma  Hepatoblastoma  Hepatocellular carcinoma  Metastatic tumors Bile duct Infection  Cholangitis, pancreatitis, or other inflammatory changes …

Feature Benign lesions Malignant lesions Pattern of growth Pushing Infiltrative No extension or penetration into surrounding bone Permeation and destruction of surrounding bone Borders of lesion Well circumscribed Ill-defined, moth-eaten…

Fig. 2.1 Supplies for pediatric FNAs. Multiple supplies are needed during pediatric FNAs because of the variety of ancillary studies that may be required. It is usually helpful to have…