Pathology is the study of the causes and effects of disease or injury. The word pathology also refers to the study of disease in general, incorporating a wide range of bioscience research fields and medical practices. However, when used in the context of modern medical treatment, the term is often used in a more narrow fashion to refer to processes and tests which fall within the contemporary medical field of "general pathology," an area which includes a number of distinct but inter-related medical specialties that diagnose disease, mostly through analysis of tissue, cell, and body fluid samples. Idiomatically, "a pathology" may also refer to the predicted or actual progression of particular diseases, and the affix path is sometimes used to indicate a state of disease in cases of both physical ailment and psychological conditions. A physician practicing pathology is called a pathologist.
Cytopathology is a branch of pathology that studies and diagnoses diseases on the cellular level. The discipline was founded by George Nicolas Papanicolaou in 1928. Cytopathology is generally used on samples of free cells or tissue fragments, in contrast to histopathology, which studies whole tissues.
A biopsy is a medical test commonly performed by a surgeon, interventional radiologist, or an interventional cardiologist involving extraction of sample cells or tissues for examination to determine the presence or extent of a disease. The tissue is generally examined under a microscope by a pathologist, and can also be analyzed chemically. When an entire lump or suspicious area is removed, the procedure is called an excisional biopsy. An incisional biopsy or core biopsy samples a portion of the abnormal tissue without attempting to remove the entire lesion or tumor. When a sample of tissue or fluid is removed with a needle in such a way that cells are removed without preserving the histological architecture of the tissue cells, the procedure is called a needle aspiration biopsy. Biopsies are most commonly performed for insight into possible cancerous and inflammatory conditions.
A granuloma is a structure formed during inflammation that is found in many diseases. It is a collection of immune cells known as macrophages. Granulomas form when the immune system attempts to wall off substances it perceives as foreign but is unable to eliminate. Such substances include infectious organisms including bacteria and fungi, as well as other materials such as keratin and suture fragments.
Interstitial lung disease (ILD), or diffuse parenchymal lung disease (DPLD), is a group of lung diseases affecting the interstitium. It concerns alveolar epithelium, pulmonary capillary endothelium, basement membrane, and perivascular and perilymphatic tissues. It may occur when an injury to the lungs triggers an abnormal healing response. Ordinarily, the body generates just the right amount of tissue to repair damage, but in interstitial lung disease, the repair process goes awry and the tissue around the air sacs (alveoli) becomes scarred and thickened. This makes it more difficult for oxygen to pass into the bloodstream. The term ILD is used to distinguish these diseases from obstructive airways diseases.
Neuropathology is the study of disease of nervous system tissue, usually in the form of either small surgical biopsies or whole-body autopsies. Neuropathologists usually work in a department of anatomic pathology, but work closely with the clinical disciplines of neurology, and neurosurgery, which often depend on neuropathology for a diagnosis. Neuropathology also relates to forensic pathology because brain disease or brain injury can be related to cause of death. Neuropathology should not be confused with neuropathy, which refers to disorders of the nerves themselves.
Fine-needle aspiration (FNA) is a diagnostic procedure used to investigate lumps or masses. In this technique, a thin, hollow needle is inserted into the mass for sampling of cells that, after being stained, will be examined under a microscope (biopsy). The sampling and biopsy considered together are called fine-needle aspiration biopsy (FNAB) or fine-needle aspiration cytology (FNAC). Fine-needle aspiration biopsies are very safe minor surgical procedures. Often, a major surgical biopsy can be avoided by performing a needle aspiration biopsy instead, eliminating the need for hospitalization. In 1981, the first fine-needle aspiration biopsy in the United States was done at Maimonides Medical Center. Today, this procedure is widely used in the diagnosis of cancer and inflammatory conditions.
Hypersensitivity pneumonitis (HP) is an inflammation of the alveoli within the lung caused by hypersensitivity to inhaled organic dusts. Sufferers are commonly exposed to the dust by their occupation or hobbies.
Cryptogenic organizing pneumonia (COP), also known as bronchiolitis obliterans organizing pneumonia (BOOP), is an inflammation of the bronchioles. It should not be confused with bronchiolitis obliterans, a form of non-infectious pneumonia.
Thoracoscopy is a medical procedure involving internal examination, biopsy, and/or resection of disease or masses within the pleural cavity and thoracic cavity. Thoracoscopy may be performed either under general anaesthesia or under sedation with local anaesthetic.
Gastrointestinal pathology is the subspecialty of surgical pathology which deals with the diagnosis and characterization of neoplastic and non-neoplastic diseases of the digestive tract and accessory organs, such as the pancreas and liver.
Usual interstitial pneumonia (UIP) is a form of lung disease characterized by progressive scarring of both lungs. The scarring (fibrosis) involves the supporting framework (interstitium) of the lung. UIP is thus classified as a form of interstitial lung disease. The term "usual" refers to the fact that UIP is the most common form of interstitial fibrosis. "Pneumonia" indicates "lung abnormality", which includes fibrosis and inflammation. A term previously used for UIP in the British literature is cryptogenic fibrosing alveolitis (CFA), a term that has fallen out of favor since the basic underlying pathology is now thought to be fibrosis, not inflammation. The term usual interstitial pneumonitis (UIP) has also often been used, but again, the -itis part of that name may overemphasize inflammation. Both UIP and CFA have been described as synonymous with idiopathic pulmonary fibrosis.
Malignant pleural effusion is a condition in which cancer causes an abnormal amount of fluid to collect between the thin layers of tissue (pleura) lining the outside of the lung and the wall of the chest cavity. Lung cancer and breast cancer account for about 50-65% of malignant pleural effusions. Other common causes include pleural mesothelioma and lymphoma.
Non-specific interstitial pneumonia (NSIP) is a form of idiopathic interstitial pneumonia.
Diffuse alveolar damage is a histological pattern in lung disease. It is seen in acute respiratory distress syndrome (ARDS), transfusion related acute lung injury (TRALI) and acute interstitial pneumonia (AIP).
Heck's disease is an asymptomatic, benign neoplastic condition characterized by multiple white to pinkish papules that occur diffusely in the oral cavity. Can present with slightly pale, smooth or roughened surface morphology. It is caused by the human papilloma virus types 13 and 32. It exhibits surface cells with vacuolated cytoplasm around irregular, pyknotic nuclei and occasional cells with mitosis-like changes within otherwise mature and well-differentiated epithelium. A distinguishing histologic feature is elongated rete ridges with mitosoid bodies present. It was first identified in the Aboriginal population of North America.
Anti-synthetase syndrome is an autoimmune disease associated with interstitial lung disease, dermatomyositis, and polymyositis.
A lung biopsy is an interventional procedure performed to diagnose lung pathology by obtaining a small piece of lung which is examined under a microscope. Beyond microscopic examination for cellular morphology and architecture, special stains and cultures can be performed on the tissue obtained.
Interventional pulmonology is a maturing medical sub-specialty from its parent specialty of pulmonary medicine. It deals specifically with minimally invasive endoscopic and percutaneous procedures for diagnosis and treatment of neoplastic as well as non-neoplastic diseases of the airways, lungs, and pleura. Many IP procedures constitute efficacious yet less invasive alternatives to thoracic surgery.
