Ghon's complex is a lesion seen in the lung that is caused by tuberculosis. The lesions consist of a calcified focus of infection and an associated lymph node. These lesions are particularly common in children and can retain viable bacteria, so are sources of long-term infection and may be involved in reactivation of the disease in later life.

In countries where cow milk infected with "Mycobacterium bovis" has been eliminated (due to culling of infected cows and pasteurization), primary tuberculosis is usually caused by "Mycobacterium tuberculosis" and almost always begins in the lungs. Typically, the inhaled bacilli implant in the distal airspaces of the lower part of the upper lobe or the upper part of the lower lobe, usually close to the pleura. As sensitization develops, a 1- to 1.5-cm area of gray-white inflammation with consolidation emerges, known as the Ghon focus. In most cases, the center of this focus undergoes caseous necrosis. Tubercle bacilli, either free or within phagocytes, drain to the regional nodes, which also often caseate. This combination of parenchymal lung lesion and nodal involvement is referred to as the Ghon complex. During the first few weeks there is also lymphatic and hematogenous dissemination to other parts of the body.

In approximately 95% of cases, development of cell-mediated immunity controls the infection.

A Ghon focus is a primary lesion usually subpleural, often in the mid to lower zones, caused by "Mycobacterium bacilli" (tuberculosis) developed in the lung of a nonimmune host (usually a child). It is named for Anton Ghon (1866–1936), an Austrian pathologist.

It is a small area of granulomatous inflammation, only detectable by chest X-ray if it calcifies or grows substantially (see tuberculosis radiology). Typically these will heal, but in some cases, especially in immunosuppressed patients, it will progress to miliary tuberculosis (so named due to the granulomas resembling millet seeds on a chest X-ray).

The classical location for primary infection is surrounding the lobar fissures, either in the upper part of the lower lobe or lower part of the upper lobe.

If the Ghon focus also involves infection of adjacent lymphatics and hilar lymph nodes, it is known as the Ghon's complex or primary complex. When a Ghon's complex undergoes fibrosis and calcification it is called a Ranke complex.

The Ghon complex undergoes progressive fibrosis, often followed by radiologically detectable calcification (Ranke complex), and despite seeding of other organs, no lesions develop. Although they are often confused, Ranke complex and Ghon complex are not synonymous. The Ranke complex is an evolution of the Ghon complex (resulting from further healing and calcification of the lesion).

The Ghon complex is named after Austrian pathologist Anton Ghon; the Ranke complex is named in honour of German pulmonologist Karl Ernst Ranke.

HIV-infected children less than 12 years of age also develop disseminated MAC. Some age adjustment is necessary when clinicians interpret CD4+ T-lymphocyte counts in children less than 2 years of age. Diagnosis, therapy, and prophylaxis should follow recommendations similar to those for adolescents and adults.

MAI is common in immunocompromised individuals, including senior citizens and those with HIV/AIDS or cystic fibrosis. Bronchiectasis, the bronchial condition which causes unnatural enlargement of the bronchial tubes, is commonly found with MAI infection. Whether the bronchiectasis leads to the MAC infection or is the result of it is not always known.

The "Mycobacterium avium complex" (MAC) includes common atypical bacteria, i.e. nontuberculous mycobacteria (NTM), found in the environment which can infect people with HIV and low CD4 cell count (below 100/microliter); mode of infection is usually inhalation or ingestion.

MAC causes disseminated disease in up to 40% of people with human immunodeficiency virus (HIV) in the United States, producing fever, sweats, weight loss, and anemia. Disseminated MAC characteristically affects people with advanced HIV disease and peripheral CD4+ T-lymphocyte counts less than 100 cells/uL. Effective prevention and therapy of MAC has the potential to contribute substantially to improved quality of life and duration of survival for HIV-infected persons.

Primary inoculation tuberculosis (also known as "Cutaneous primary complex," "Primary tuberculous complex," and "Tuberculous chancre") is a skin condition that develops at the site of inoculation of tubercle bacilli into a tuberculosis-free individual.

The reported incidence of constriction ring syndrome varies from 1/1200 and 1/15000 live births. The prevalence is equally in male and female.

Fetomaternal factors like prematurity, maternal illnes, low birth weight and maternal drug exposure are predisposing factors for the constriction ring syndrome.

No positive relationship between CRS and genetic inheritance has been reported.

An odontoma (also termed odontome) is a benign tumour of odontogenic origin (i.e. linked to tooth development). Specifically, it is a dental hamartoma, meaning that it is composed of normal dental tissue that has grown in an irregular way.

The average age of people found with an odontoma is 14. The condition is frequently associated with one or more unerupted teeth. Though most cases are found impacted within the jaw there are instances where odontomas have erupted into the oral cavity.

Odontomas are thought to be the second most frequent type of odontogenic tumor worldwide (after ameloblastoma), accounting for about 20% of all cases within this relatively uncommon tumor category which shows large geographic variations in incidence.

Cardiac myxomas can be difficult to manage surgically because of recurrence within the heart, often far away from the site of the initial tumor.

Ashman phenomenon, also known as Ashman beats, describes a particular type of wide QRS complex, often seen isolated that is typically seen in atrial fibrillation. It is more often misinterpreted as a premature ventricular complex.

It is named for Richard Ashman (of New Orleans) (1890 –1969), after first being described by Gouaux and Ashman in 1947.

Surgical correction is recommended when a constriction ring results in a limb contour deformity, with or without lymphedema.

Generalized lentiginosis is a cutaneous condition that will occasionally present without other associated abnormalities. It may be caused by carney complex, LEOPARD syndrome or Peutz–Jeghers syndrome.

Sensenbrenner syndrome (OMIM #218330) is a rare (less than 20 cases reported by 2010) multisystem disease first described in 1975. It is inherited in an autosomal recessive fashion, and a number of genes appear to be responsible. Three genes responsible have been identified: intraflagellar transport (IFT)122 (WDR10), IFT43 — a subunit of the IFT complex A machinery of primary cilia, and WDR35 (IFT121: TULP4)

It is also known as Sensenbrenner–Dorst–Owens syndrome, Levin Syndrome I and cranioectodermal dysplasia (CED)

AIDS-related complex, or ARC, was introduced after discovery of the HIV (Human Immunodeficiency Virus) when the medical community became aware of the inherent difficulties associated with treating patients suffering from an advanced case of HIV which gave rise to the term Acquired Immune Deficiency Syndrome (AIDS). The necessity for doctors to quickly and accurately understand the special needs of unknown patients suffering from AIDS in an emergency room situation was addressed with the creation of the term ARC.

ARC is "A prodromal phase of infection with the human immunodeficiency virus (HIV). Laboratory criteria separating AIDS-related complex ( ARC) from AIDS include elevated or hyperactive B-cell humoral immune responses, compared to depressed or normal antibody reactivity in AIDS; follicular or mixed hyperplasia in ARC lymph nodes, leading to lymphocyte degeneration and depletion more typical of AIDS; evolving succession of histopathological lesions such as localization of Kaposi's sarcoma, signaling the transition to the full-blown AIDS."

Clinical use of this term was widely discontinued by the year 2000 in the United States after having been replaced by modern laboratory criteria.

A bile duct hamartoma or biliary hamartoma, is a benign tumour-like malformation

of the liver.

They are classically associated with polycystic liver disease, as may be seen in the context of polycystic kidney disease, and represent a malformation of the liver plate.

Papillary adenocarcinoma is a histological form of lung cancer that is diagnosed when the malignant cells of the tumor form complex papillary structures and exhibit compressive, destructive growth that replaces the normal lung tissue.

Clinically, it is often asymptomatic by itself and considered benign in nature.

X-linked myopathy with excessive autophagy (XMEA) is a rare childhood onset disease characterized by slow progressive vacuolation and atrophy of skeletal muscle. There is no known cardiac or intellectual involvement.

The Mazzotti reaction, first described in 1948, is a symptom complex seen in patients after undergoing treatment of onchocerciasis with the medication diethylcarbamazine (DEC). Mazzotti reactions can be life-threatening, and are characterized by fever, urticaria, swollen and tender lymph nodes, tachycardia, hypotension, arthralgias, oedema, and abdominal pain that occur within seven days of treatment of microfilariasis. The Mazzotti reaction correlates with intensity of infection; however, there are probably multiple infection intensity-dependent mechanisms responsible for mediating this complex reaction.

The phenomenon is so common when DEC is used for the treatment of onchocerciasis that this drug is the basis of a skin patch test used to confirm that diagnosis. The drug patch is placed on the skin, and if the patient is infected with the microfilaria of "O. volvulus", localized pruritus and urticaria are seen at the application site.

A case of the Mazzotti reaction has been reported after presumptive treatment of schistosomiasis and strongyloidiasis with ivermectin, praziquantel and albendazole. The patient had complete resolution of symptoms after intravenous therapy with methylprednisolone.

PPNAD, the endocrine manifestation that comes from Carney Complex (CNC), can be syndromic or isolated. The main cause of isolated PPNAD is a mutation of PRKAR1α, located at 17q22-24, which is the gene encoding the regulatory R1α subunit of protein kinase A. Germline heterozygous PRKAR1α inactivation mutations are present in 80% of CNC patients affected by Cushing's syndrome. There are over 117 mutations of the PRKAR1α gene that can cause CNC, with many of these mutations producing premature stop codons, thus resulting in the complete loss of PRKAR1α protein. CNC patients have also been discovered with an unusually shortened PRKAR1α protein, detected in tumours and leukocytes, following a splice-site mutation, which causes exon-6 skipping. Therefore, both haploinsufficiency and the complete loss of PRKAR1α can lead to the increased PKA activity observed in PPNAD patients, due to the disruption of the cAMP signalling pathway.

Sahut-Barnola et al. used a mouse model to cre-lox knockout the Prkar1a gene specifically from cells of the adrenal cortex and observed that the mice subsequently developed Cushing syndrome that is independent of the pituitary. They also observed that the mutation caused increased PKA activity.

The R1α loss caused the adult adrenal gland became hyperactive and hyperplastic on both sides, as seemingly the foetal adrenal cells within it were not maintained and thus expanded. This established tumoral growths. This mouse KO model phenocopies what happens in human cases of PPNAD.

Inactivation of PDE11A4, located at 2q31-5, has also been identified in PPNAD patients without PRKAR1α mutations. PDE11A4 is the gene encoding phosphodiesterase 11A4, another participant of the cAMP signalling pathway.

, one of the Four Big Pollution Diseases of Japan, occurred in the city of Yokkaichi in Mie Prefecture, Japan, between 1960 and 1972. The burning of petroleum and crude oil released large quantities of sulfur oxide that caused severe smog, resulting in severe cases of chronic obstructive pulmonary disease, chronic bronchitis, pulmonary emphysema, and bronchial asthma among the local inhabitants. The generally accepted sources of the sulfur oxide pollution were petrochemical processing facilities and refineries that were built in the area between 1957 and 1973.

Primary pigmented nodular adrenocortical disease (PPNAD) was first coined in 1984 by Carney et al. it often occurs in association with Carney complex (CNC). CNC is a rare syndrome that involves the formation of abnormal tumours that cause endocrine hyperactivity.

PPNAD arises due to the enlargement of the cortex of the adrenal glands, resulting in Cushing's syndrome that is independent of the pituitary hormone ACTH.

Beginning shortly after the opening of the first complex in 1956, severe cases of chronic obstructive pulmonary disease, chronic bronchitis, pulmonary emphysema, and bronchial asthma rose quickly among the local inhabitants. Taller smokestacks were implemented, but these simply spread the pollution over a wider area and did not help alleviate the reported health issues.

Fish caught in Ise Bay developed a bad taste, causing local fishermen to petition the government for compensation for their unsaleable fish in 1960.

Bare lymphocyte syndrome is a condition caused by mutations in certain genes of the major histocompatibility complex or involved with the processing and presentation of MHC molecules. It is a form of severe combined immunodeficiency.