Diffuse Splenic Lesions
Normal Variants and Congenital Anomalies The spleen begins to develop during the fifth week of embryogenesis when mesenchymal cells aggregate between the two leaves of the dorsal mesogastrium to form…
Diffuse Renal Parenchymal Diseases
Renal failure may be classified as prerenal when secondary to a reduction in the renal perfusion pressure gradient, renal when the result of intrinsic disease of the renal parenchyma, and…
Abdominal Wall Hernias
Etiology Abdominal wall hernias, or external hernias (where abdominal contents protrude beyond the abdominal cavity), include inguinal, femoral, umbilical, incisional, spigelian, epigastric, lumbar, and obturator hernias. All abdominal wall hernias…
Renal Vascular Diseases
Renovascular Hypertension Etiology The most common cause of renovascular hypertension is renal artery stenosis, which may be caused by atherosclerosis (70% to 90%) or less commonly by fibromuscular dysplasia (10%…
Penile Trauma and Miscellaneous Penile Lesions
Etiology Penile lesions can be categorized by cause ( Box 76-1 ). Box 76-1 Penile Pathologic Processes • Trauma • Blunt trauma • Penetrating or sharp trauma • Acute bending…
Erectile Dysfunction
Etiology Erectile dysfunction manifests clinically most commonly as impotence and less commonly as priapism. The causes of impotence can be psychogenic, endocrinologic, neurogenic, anatomic, infectious, pharmacologic, or vasogenic. Vasogenic causes…
Focal Splenic Lesions
Splenic Cysts Non-Neoplastic and Nonparasitic Splenic Cysts Etiology Non-neoplastic and nonparasitic splenic cysts are classified into primary (i.e., epithelial, true) and secondary (i.e., pseudocysts, false) cysts, depending on the presence…
Benign and Malignant Bladder Lesions
The urinary bladder is composed of the following four layers: 1. Urothelium: Transitional epithelium 2. Lamina propria: Vascular layer of connective tissue deep to the urothelium 3. Muscularis propria: Detrusor…
Enlarged Adrenal Glands
Recent technical advances in computed tomography (CT) and magnetic resonance imaging (MRI) have resulted in improved detection of subtle changes in adrenal gland morphology. The different morphologic patterns of adrenal…
Miscellaneous Pancreatitis
Autoimmune Pancreatitis Etiology Autoimmune pancreatitis (AIP) is a peculiar form of chronic pancreatitis characterized by a fibroinflammatory process involving multiple organs with characteristic histopathologic and serologic features, association with other…
