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(sī′nŭ-skōp″) [sinus + -scope] An endoscope used to look inside the structures of the nose, sinuses, and throat.

sinus histiocytosis with massive lymphadenopathy

Rosai-Dorfman disease.


(sī-nŭs-ī′tĭs) [L. sinus, curve, hollow, + Gr. itis, inflammation] Inflammation of a sinus, esp. a paranasal sinus. It may be caused by various agents, including viruses, bacteria, or allergy. Predisposing factors include inadequate drainage, which may result from presence of polyps, enlarged turbinates, or a deviated septum; chronic rhinitis; general debility; or dental abscess in maxillary bone.

acute suppurative s. Purulent inflammation with pain over the facial sinuses, often accompanied by fever, chills, and headache.

 TREATMENT: Therapy is conservative. Shrinkage in the nasal mucosa is useful to facilitate ventilation and drainage of the sinus. The patient should rest, force fluids, take decongestants, and apply hot packs. If inflammation is due to bacterial infection, antibiotic therapy is indicated.

allergic fungal s. Chronic nasal obstruction with symptoms that include a runny nose and postnasal discharge caused by allergies to soil-based fungi (such as Curvularia or Alternaria). The condition is occasionally diagnosed in patients with an allergic history and nasal polyposis who have failed treatments for other sinus diseases. Tenacious mucus with a large number of eosinophils is often present.

chronic hyperplastic s. Polyps present in sinuses and nose and underlying osteitis of sinus walls.

 TREATMENT: This condition is treated surgically. Conservative surgery involves the removal of polyps and intranasal opening into sinuses for adequate ventilation and drainage. Radical surgery involves the complete removal of sinus mucosa through either the external or the intranasal route.

invasive fungal s. Sinus, ophthalmic, and cerebral invasion by opportunistic fungi. The disease usually occurs in immunosuppressed patients (such as diabetic or neutropenic patients) and is frequently fatal despite aggressive medical and surgical therapies. Aspergillus, Mucor, and Rhizopus are the most commonly implicated causes.


(sī′nŭs-oyd″) [sinus + -oid] 1. Resembling a sinus. 2. A large, permeable capillary, often lined with macrophages, found in organs such as the liver, spleen, bone marrow, and adrenal glands. Their permeability allows cells or large proteins to easily enter or leave the blood. sinusoidal (sī″nŭs-oyd′ăl), adj.

sinusoidal current

Alternating induced electric current, the two strokes of which are equal.

sinusoidal obstruction syndrome

(sī″nŭs-oyd′ăl) ABBR: SOS. A disruption in the normal flow of venous blood from the sinusoids of the liver and the hepatic venules. It occurs primarily after hematopoietic (stem) cell transplantation and is characterized by enlargement of the liver, right upper quadrant pain, jaundice, and massive fluid retention in the peritoneum (ascites) within the ...

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