Nodular regenerative hyperplasia is a form of liver hyperplasia associated with portal hypertension.

Nodular regenerative hyperplasia (NRH) is a rare liver condition characterized by a widespread benign transformation of the hepatic parenchyma into small regenerative nodules. NRH may lead to the development of non-cirrhotic portal hypertension. There are no published systematic population studies on NRH and our current knowledge is limited to case reports and case series. NRH may develop "via" autoimmune, hematological, infectious, neoplastic, or drug-related causes. It is associated with rheumatoid arthritis, Felty syndrome, myeloproliferative disorders, liver, kidney and bone marrow transplantation, cytotoxic drugs like azathioprine, mercaptopurine, thioguanine, antiretroviral drugs for HIV like didanosine and vitamin A. The disease is usually asymptomatic, slowly or non-progressive unless complications of portal hypertension develop. Accurate diagnosis is made by histopathology, which demonstrates diffuse micronodular transformation without fibrous septa. Lack of perinuclear collagen tissue distinguishes NRH from typical regenerative nodules in the cirrhotic liver. While the initial treatment is to address the underlying disease, ultimately the therapy is directed to the management of portal hypertension. The prognosis of NRH depends on both the severity of the underlying illness and the prevention of secondary complications of portal hypertension. In this review we detail the epidemiology, pathogenesis, diagnosis, management, and prognosis of NRH.

It can be a complication of azathioprine therapy.

To date, no treatment has been proven to effectively reverse or prevent the progression of PAM. Lung transplantation is an option for end stage disease, but is typically only recommended as a last resort when quality of life is significantly impaired.

Etidronate is a bisphosphonate and can reduce the formation of calcium hydroxyapatite crystals. It has led to clinical and radiological improvements in few cases.

PAM is one of the rare lung diseases currently being studied by the Rare Lung Diseases Consortium (RLDC). Pulmonary Alveolar Microlithiasis patients, families, and caregivers are encouraged to join the NIH Rare Lung Diseases Consortium Contact Registry. This is a privacy protected site that provides up-to-date information for individuals interested in the latest scientific news, trials, and treatments related to rare lung diseases.

As the number of published cases of AIP has increased, efforts have been focused on defining AIP as a distinct clinical and pathologic entity and toward developing some generally agreed upon diagnostic criteria and nomenclature. Terms frequently encountered are autoimmune or autoimmune-related pancreatitis, lymphoplasmacytic sclerosing pancreatitis, idiopathic tumefactive chronic pancreatitis, idiopathic pancreatitis with focal irregular narrowing of the main pancreatic duct, and non-alcoholic duct destructive chronic pancreatitis. There are also a large number of case reports employing descriptive terminology such as pancreatitis associated with Sjögren’s syndrome, primary sclerosing cholangitis, or inflammatory bowel disease. Some of the earliest cases were reported as pancreatic pseudotumor or pseudolymphoma.

AIP often completely resolves with steroid treatment. The failure to differentiate AIP from malignancy may lead to unnecessary pancreatic resection, and the characteristic lymphoplasmacytic infiltrate of AIP has been found in up to 23% of patients undergoing pancreatic resection for suspected malignancy who are ultimately found to have benign disease. In this subset of patients, a trial of steroid therapy may have prevented a Whipple procedure or complete pancreatectomy for a benign disease which responds well to medical therapy. "This benign disease resembles pancreatic carcinoma both clinically and radiographically. The diagnosis of autoimmune pancreatitis is challenging to make. However, accurate and timely diagnosis may preempt the misdiagnosis of cancer and decrease the number of unnecessary pancreatic resections." Autoimmune pancreatitis responds dramatically to corticosteroid treatment.

If relapse occurs after corticosteroid treatment or corticosteroid treatment is not tolerated, immunomodulators may be used. Immunomodulators such as azathioprine, and 6-mercaptopurine have been shown to extend remission of autoimmune pancreatitis after corticosteroid treatment. If corticosteroid and immunomodulator treatments are not sufficient, rituximab may also be used. Rituximab has been shown to induce and maintain remission.

The first cases of NSF were identified in 1997, but NSF was first described as an independent disease entity in 2000. While skin involvement is on the foreground, the process may involve any organ and resembles diffuse scleroderma or systemic sclerosis. In 2006, the link between NSF and gadolinium-containing contrast agents was made. As a result, gadolinium-containing contrast is now considered contraindicated in patients with an estimated glomerular filtration rate (a measure of renal function) under 60 and especially under 30 ml/mn. One retrospective study of the Veterans Affairs Electronic Medical Record found no cases of NSF among 141 patients receiving hemodialysis for chronic kidney disease who received gadoteridol.

NSF has also developed in patients with acute kidney injury, even if renal function subsequently returned to normal following GBCM administration [15]. In one series, up to 20% of NSF cases were diagnosed in patients who had been in some element of transient acute renal failure (often, but not always, superimposed upon chronic kidney disease) at the time of GBCM administration.

This classification was released after another proposition would have left the safest category (ionic cyclical structure) with only one agent ("Dotarem"). The intermediate category would have been both ionic linear structure and non-ionic cyclical structure. The third category most at risk was unchanged (linear non-ionic).

The goal of treatment is the induction and maintenance of remission so as to prevent progression of fibrosis and organ destruction in affected organ(s).

An international panel of experts have developed recommendations for the management of IgG4-RD. They concluded that in all cases of symptomatic, active IgG4-RD that treatment is required. Some cases with asymptomatic IgG4-RD also require treatment, as some organs tend to not cause symptoms until the late stages of disease. Urgent treatment is advised with certain organ manifestations, such as aortitis, retroperitoneal fibrosis, proximal biliary strictures, tubulointerstitial nephritis, pachymeningitis, pancreatic enlargement and pericarditis.

Following a successful induction of remission, maintenance therapy might be given in some cases, for example when there is a high risk of relapse or in patients with organ-threatening manifestations. Common maintenancy therapy is prednisolone 2.5–5 mg per day, or use of a steroid-sparing agent instead.

Progressive nodular histiocytoma is a cutaneous condition characterized by generalized, discrete yellow papules and nodules with prominent facial involvement.

Prurigo nodularis is very hard to treat, but current therapies include steroids, vitamins, cryosurgery, thalidomide and UVB light. In the event that staphylococcus or other infection is present, antibiotics have proven effective, but tend to cause more harm than good for this particular disease.

A physician may administer a strong dose of prednisone, which will almost immediately stop the itch/scratch cycle. However, cessation of steroids allows relapse to occur, usually within a few weeks. Horiuchi "et al" recently reported significant improvement in PN with antibiotic therapy.

Another drug a physician may administer is Apo-Azathioprine. Azathioprine, also known by its brand name Imuran, is an immunosuppressive drug used in organ transplantation and autoimmune diseases and belongs to the chemical class of purine analogues.

Focal nodular hyperplasia (FNH) is a benign tumor of the liver (hepatic tumor), which is the second most prevalent tumor of the liver (the first is hepatic hemangioma). It is usually asymptomatic, rarely grows or bleeds, and has no malignant potential. This tumour was once often resected because it was difficult to distinguish from hepatic adenoma, but with modern multiphase imaging is usually now diagnosed by strict imaging criteria and not resected.

Nodular fasciitis, also known as nodular pseudosarcomatous fasciitis, pseudosarcomatous fasciitis, and subcutaneous pseudosarcomatous fibromatosis, is a benign soft tissue lesion most commonly found in the superficial fascia. The lesion commonly occurs in the first three decades of life. Upper extremities and trunk are the most common affected anatomical sites. Previous history of trauma may be present. Clinically and histologically, nodular fasciitis may be mistaken for a sarcoma.

ILD is not a single disease, but encompasses many different pathological processes. Hence treatment is different for each disease.

If a specific occupational exposure cause is found, the person should avoid that environment. If a drug cause is suspected, that drug should be discontinued.

Many cases due to unknown or connective tissue-based causes are treated with corticosteroids, such as prednisolone. Some people respond to immunosuppressant treatment. Patients with a low level of oxygen in the blood may be given supplemental oxygen.

Pulmonary rehabilitation appears to be useful. Lung transplantation is an option if the ILD progresses despite therapy in appropriately selected patients with no other contraindications.

On October 16, 2014, the Food and Drug Administration approved a new drug for the treatment of Idiopathic Pulmonary Fibrosis (IPF). This drug, Ofev (nintedanib), is marketed by Boehringer Ingelheim Pharmaceuticals, Inc. This drug has been shown to slow the decline of lung function although the drug has not been shown to reduce mortality or improve lung function. The estimated cost of the drug per year is approximately $94,000.

In terms of possible treatment for the condition of idiopathic sclerosing mesenteritis, medications such as corticosteroids, tamoxifen and thalidomide have been used.

Until recently, nodular fasciitis have been considered a reactive process of uncertain cause. However, recent findings indicate that nodular fasciitis is a self-limited clonal neoplastic process (see below). Clinically, nodular fasciitis presents as a subcutaneous "growth" over a period of 3–6 weeks that eventually regresses. The lesion usually reaches a size of 2–3 cm. Larger lesions are unusual. Local recurrence has been described after simple surgical excision but it is rare.

Equine multinodular pulmonary fibrosis is a chronic lung disease of horses. There is evidence that the disease is caused by infection with a gammaherpesvirus, equine herpesvirus 5. The disease affects adult (usually older) horses, causing weight loss and reduced ability to exercise as a result of the formation of nodular lesions in the lungs.

Once tuberculosis has been excluded, treatment is with steroids. All exposure to coal dust must be stopped, and smoking cessation should be attempted. Rheumatoid arthritis should be treated normally with early use of DMARDs.

FNH is not a true neoplasm; it is believed to result from localized hyperplastic hepatocyte response to an underlying congenital arteriovenous malformation. It consists of normal liver constituents in an abnormally organized pattern, grows in a stellate pattern and may display central necrosis when large. Additionally evidence suggests that the incidence of FNH is related to oral contraceptive use.

Mortality is indirect and caused by complications. After cholangitis occurs, patients typically die within 5–10 years.

Benign nephrosclerosis refers to the renal changes most commonly occurring in association with long-standing hypertension. It is termed benign because it rarely progresses to clinically significant renal insufficiency or renal failure.

Superficial spreading melanoma (also known as "superficially spreading melanoma") (SSM) is usually characterized as the most common form of cutaneous melanoma in Caucasians. The average age at diagnosis is in the fifth decade, and it tends to occur on sun-exposed skin, especially on the backs of males and lower limbs of females.

Many conditions affect the human integumentary system—the organ system covering the entire surface of the body and composed of skin, hair, nails, and related muscle and glands. The major function of this system is as a barrier against the external environment. The skin weighs an average of four kilograms, covers an area of two square meters, and is made of three distinct layers: the epidermis, dermis, and subcutaneous tissue. The two main types of human skin are: glabrous skin, the hairless skin on the palms and soles (also referred to as the "palmoplantar" surfaces), and hair-bearing skin. Within the latter type, the hairs occur in structures called pilosebaceous units, each with hair follicle, sebaceous gland, and associated arrector pili muscle. In the embryo, the epidermis, hair, and glands form from the ectoderm, which is chemically influenced by the underlying mesoderm that forms the dermis and subcutaneous tissues.

The epidermis is the most superficial layer of skin, a squamous epithelium with several strata: the stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, and stratum basale. Nourishment is provided to these layers by diffusion from the dermis, since the epidermis is without direct blood supply. The epidermis contains four cell types: keratinocytes, melanocytes, Langerhans cells, and Merkel cells. Of these, keratinocytes are the major component, constituting roughly 95 percent of the epidermis. This stratified squamous epithelium is maintained by cell division within the stratum basale, in which differentiating cells slowly displace outwards through the stratum spinosum to the stratum corneum, where cells are continually shed from the surface. In normal skin, the rate of production equals the rate of loss; about two weeks are needed for a cell to migrate from the basal cell layer to the top of the granular cell layer, and an additional two weeks to cross the stratum corneum.

The dermis is the layer of skin between the epidermis and subcutaneous tissue, and comprises two sections, the papillary dermis and the reticular dermis. The superficial papillary dermis with the overlying rete ridges of the epidermis, between which the two layers interact through the basement membrane zone. Structural components of the dermis are collagen, elastic fibers, and ground substance. Within these components are the pilosebaceous units, arrector pili muscles, and the eccrine and apocrine glands. The dermis contains two vascular networks that run parallel to the skin surface—one superficial and one deep plexus—which are connected by vertical communicating vessels. The function of blood vessels within the dermis is fourfold: to supply nutrition, to regulate temperature, to modulate inflammation, and to participate in wound healing.

The subcutaneous tissue is a layer of fat between the dermis and underlying fascia. This tissue may be further divided into two components, the actual fatty layer, or panniculus adiposus, and a deeper vestigial layer of muscle, the panniculus carnosus. The main cellular component of this tissue is the adipocyte, or fat cell. The structure of this tissue is composed of septal (i.e. linear strands) and lobular compartments, which differ in microscopic appearance. Functionally, the subcutaneous fat insulates the body, absorbs trauma, and serves as a reserve energy source.

Conditions of the human integumentary system constitute a broad spectrum of diseases, also known as dermatoses, as well as many nonpathologic states (like, in certain circumstances, melanonychia and racquet nails). While only a small number of skin diseases account for most visits to the physician, thousands of skin conditions have been described. Classification of these conditions often presents many nosological challenges, since underlying etiologies and pathogenetics are often not known. Therefore, most current textbooks present a classification based on location (for example, conditions of the mucous membrane), morphology (chronic blistering conditions), etiology (skin conditions resulting from physical factors), and so on. Clinically, the diagnosis of any particular skin condition is made by gathering pertinent information regarding the presenting skin lesion(s), including the location (such as arms, head, legs), symptoms (pruritus, pain), duration (acute or chronic), arrangement (solitary, generalized, annular, linear), morphology (macules, papules, vesicles), and color (red, blue, brown, black, white, yellow). Diagnosis of many conditions often also requires a skin biopsy which yields histologic information that can be correlated with the clinical presentation and any laboratory data.

Caroli disease is typically found in Asia, and diagnosed in persons under the age of 22. Cases have also been found in infants and adults. As medical imaging technology improves, diagnostic age decreases.

The nodules may pre-date the appearance of rheumatoid arthritis by several years. Otherwise prognosis is as for RA; lung disease may remit spontaneously, but pulmonary fibrosis may also progress.