Bull’s Eye

A common adjective referring to a rounded appearance, lesion, mass or pattern that is circumferentially rimmed by 2+ distinct densities or colours; the inner circle is often dark—or radiopaque—rimmed by a lighter—or radiolucent—ring that in turn is surrounded by a third, dark or radiopaque circle; the opposite—light-dark-light—has been called a doughnut pattern
Dermatology A bull’s eye pattern—of discrete, irregular, flat, dark red, purpuric macules with a central vesicle—is a characteristic finding in erythema multiforme, which is mediated by circulating immune complexes, and triggered by infections, drugs, or connective tissue disease. A bull’s-eye lesion is also a classic finding in Lyme disease and seen 1–3 weeks before the onset of arthritic symptoms
Endoscopy A finding in the gastrointestinal lumen, in which oedematous folds surround a central depression—mass lesion—with a central ulcer, a non-specific finding seen in solitary amebomas, actinomycosis, amyloidosis, appendiceal disease, and tuberculosis; single bull’s-eyes include submucosal carcinoid, primary carcinoma, Kaposi sarcoma, leiomyoma, leiomyosarcoma, lipoma, and lymphoma; multiple bull’s-eyes occur in metastases from primary breast, lung, and renal carcinoma, lymphoma, and mastocytosis
Herbal medicine, Homeopathy Calendula, see there, Calendula officinalis
General bull’s eyes Bull’s-eyes similar to those seen by endoscopy are caused by centrally ulcerated lesions, suggestive of cancer, in which the central zone is hypodense—i.e., necrotic—implying a rapidly proliferating lesion that has outgrown its vascular supply and typically occur in metastastic foci of lung or colorectl cancer in the liver; multifocal bull’s-eyes are suggestive of melanoma; unifocal bull’s-eyes occur in cancers metastatic to the GI tract, benign or malignant smooth muscle tumours of the intestinal wall, Kaposi and other sarcomas, eosinophilic granuloma, and ectopic pancreatic tissue.
GI tract A bull’s eye appearance with the lumen of the intestine may indicate intussusception
Elasticity imaging Benign single cysts and multicystic lesions of the breast have a bull’s eye appearance, which is regarded as a relatively reliable indicator of benignancy
Ophthalmology Bull’s eye maculopathy A fundoscopic finding seen in chloroquine-induced retinopathy, in which a depigmented lesion surrounds the macula, surrounded by another ring of relative hyperpigmentation, with possible permanent loss of visual acuity. The term bull’s eye has also been used in reference to the ocular fundus in a case of pseudoexfoliation glaucoma
Pathology An uncommon histologic finding in breast carcinoma, in which vacuoles have a central spot that variably stains with Giemsa, H&E, or PAS, possibly a processing artifact