Thymic Cyst Clinical Features Uncommon; constitutes less than 10% of mediastinal cysts May be congenital or acquired Found in the anterior mediastinum but may occur in ectopic locations such as neck, pleura, and posterior mediastinum Invariably benign Age range: 20…
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 parenchyma (formerly congenital cystic adenomatoid malformation [CCAM]) Often detected by antenatal…
Thyroid Gland Granulomatous Thyroiditis (De Quervain Thyroiditis) Clinical Features Also called subacute thyroiditis Presents with clinically marked tenderness of thyroid, fever, sore throat, and malaise most likely related to systemic viral illness Most commonly affects middle-aged women Majority of cases…
Inflammatory Conditions Superficial Perivascular Dermatitis Dermatitis With Minimal Epidermal Changes Superficial Dermatophytosis (Tinea) Clinical Features Caused by three genera of imperfect fungi— Epidermophyton, Trichophyton, and Microsporum —that cause superficial infections involving keratinized tissues such as the cornified layer of epidermis,…
Light Microscopy Tissue Processing Overview Fixation Preserves tissues in situ as close to the lifelike state as possible Ideally, fixation will be carried out as soon as possible after removal of the tissues, and the fixative will kill the tissue…
Liver Transplantation Liver transplantation is performed in patients with liver failure caused by acute or chronic liver disease, selected hepatic tumors, and some metabolic diseases. Approximately 7000 liver transplants (LT) are performed annually in the United States. The graft survival…
The gastrointestinal (GI) tract is the most common site of extranodal lymphoma, which should not be a surprise as the GI system contains approximately 70% of the lymphoid tissue and 80% of the plasma cells (most of those being immunoglobulin…
Primary hepatocellular neoplasms are much less common than metastatic tumors to the liver. The former may arise from either the epithelial or mesenchymal component of the hepatic parenchyma and rarely may also show both lines of differentiation. Hepatocellular neoplasms may…
Major Histologic Patterns of Injury Because the liver presents with a relatively small repertoire of responses to injury, there is significant histologic overlap among liver diseases, making specific diagnosis challenging. A pattern-based approach enables the pathologist to generate a relatively…
Non-Neoplastic Diseases Developmental Anomalies The three most commonly encountered developmental anomalies of the pancreas in routine surgical pathology practice are pancreas divisum, annular pancreas, and ectopic pancreas. Pancreas Divisum Pancreas divisum occurs in 3% to 7% of the population as…