Vitamin A

What Are Extraintestinal Lymphomas? Extraintestinal lymphomas (non-Hodgkin’s) are malignancies that arise in peripheral lymphatic tissue outside the intestinal tract from B-cell and T-cell lymphocytes. Q: What is peripheral lymphatic tissue? A: Peripheral lymphatic tissue includes lymph vessels, lymph, lymph nodes, and ...

What Is Refractory Celiac Disease? Refractory celiac disease, formerly called refractory sprue, is a severe complication characterized by persistence of symptoms and intestinal inflammation despite gluten free diet after 12 months.1 Refractory celiac disease appears in two forms, ulcerative jejunitis (RCD ...

What Is B-Cell Non-Hodgkin’s Lymphoma? Bcell non-Hodgkin’s lymphoma is a malignant, monoclonal (arising from a single cell) proliferation of lymphocytes that is preceded by lymphadenopathy and characterized by varying, less predictable spread than Hodgkin’s disease. Lymphadenopathy is enlargement of lymph ...

What Is Pruritic Skin? Pruritic skin is a symptom of a primary disease that may involve only the skin or a systemic disorder with other features and is characterized by chronic itching. Q: What part of skin is affected by ...

What Is Pityriasis Rubra Pilaris? Pityriasis rubra pilaris (PRP) is a chronic generalized exfoliative dermatitis (sloughing skin) characterized by erythema (redness), scaling, dilated plugged hair follicles, and keratoderma (thickened skin) of the hands and feet that is often associated with ...

What Is Follicular Hyperkeratosis? Follicular hyperkeratosis is an abnormal skin condition characterized by disordered overgrowth of the horny layer of the epidermis with horny plugs filling the openings of hair follicles. The plugs look like bumps in hair follicles. Follicular ...

What Is Acquired Cutis Laxa? Acquired cutis laxa is an uncommon skin disorder characterized by abnormal reduction and degeneration of elastic fibers of the skin that can appear simply as thick, saggy skin with loose folds to severe involvement showing ...

What Is Cancer Of The Esophagus? Cancer of the esophagus is a malignancy arising in the stratified squamous cell lining of any part of the esophagus and having a poor prognosis. This tumor first invades the deeper layers of the ...

What Is Post-Cricoid Carcinoma? Post-cricoid carcinoma is a rare malignancy arising in the hypopharynx. Q: What is the hypopharynx? A: The hypopharynx is the lower portion of the pharynx that opens into the larynx. It is comprised of the postcricoid ...