Central Nervous System
Diffuse Astrocytic Tumors Diffuse Astrocytomas of Each Grade are Now Divided Into One of Two Diagnostic Categories Based Upon the Isocitrate Dehydrogenase (IDH Gene Mutation Status (IDH Mutant or IDH…
Lymph Nodes
Normal Lymph Node Histopathology • A lymph node contains a cortex, a paracortex, a medulla, sinuses, a hilum, and a fibrous capsule • The cortex is a B-cell area, which…
Soft Tissue
Nodular Fasciitis Clinical Features • Primarily affects young adults aged 20 to 40 years; occasionally seen in children • Presents as a rapidly growing solitary mass; may be painful •…
Hepatobiliary System
Viral Hepatitis Clinical Features Hepatitis A Virus • Single-stranded RNA (ssRNA) virus (picornavirus) • Transmission route: fecal-oral • Incubation: 2 to 6 weeks • Self-limited • Not associated with chronic…
Eye and Orbit
Adult Ocular Lesions External Lesions Malignant Melanoma of the Conjunctiva Clinical Features † Deceased • Usually pigmented (may be amelanotic), nodular, elevated lesion with vascularity, anywhere on conjunctiva • Usually…
Bones and Joints
Osteoid Tumors Osteoma Clinical Features • Male predominance (2:1 to 3:1) • Age ranges from second decade to elderly, with most cases occurring in fourth and fifth decades • Occurs…
Heart, Pericardium, and Blood Vessels
Heart Cardiomyopathy Clinical Features Hypertrophic Cardiomyopathy • Myocardial disease characterized by left ventricular hypertrophy in the absence of systemic hypertension, aortic valve stenosis, or overt infiltrative diseases • Associated with…
Lung and Pleura
Non-Neoplastic Conditions Congenital Pulmonary Airway Malformation Clinical Features • Uncommon developmental anomaly predominantly seen in infants that has features of both immaturity and malformation of the airways and distal lung…
