medicine Medicine is the science and Praxis (process), practice of caring for patients, managing the Medical diagnosis, diagnosis, prognosis, Preventive medicine, prevention, therapy, treatment, Palliative care, palliation of their injury or disease, ...

, a targetoid object is a structure or

lesion A lesion is any damage or abnormal change in the tissue of an organism, usually caused by injury or diseases. The term ''Lesion'' is derived from the Latin meaning "injury". Lesions may occur in both plants and animals. Types There is no de ...

that has the appearance of a

target Target may refer to: Warfare and shooting * Shooting target, used in marksmanship training and various shooting sports ** Bullseye (target), the goal one for which one aims in many of these sports ** Aiming point, in field artille ...

or is target-like. Targetoid lesions are distinguished by a concentric ring-like appearance that resembles a target or bull's-eye. Classic target lesions with three concentric zones are commonly associated with

erythema multiforme Erythema multiforme (EM) is an immune-mediated inflammatory skin condition associated with several viral infections, that appears with red patches evolving into target lesions, typically on both hands. It is typically associated with infection ...

(a type of skin rash), while targetoid lesions with only two zones can appear in various dermatological conditions. Such lesions can be critical in diagnosing numerous skin disorders, ranging from infectious and inflammatory diseases to drug reactions and some

neoplasm A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...

s. Recognizing differences in morphology, distribution, and symptoms of targetoid lesions is important for accurate diagnosis and management of these distinctive skin lesions. The differential diagnosis of targetoid lesions is broad and includes conditions such as

hives Hives, also known as urticaria, is a kind of skin rash with red or flesh-colored, raised, itchy bumps. Hives may burn or sting. The patches of rash may appear on different body parts, with variable duration from minutes to days, and typically ...

(urticaria), fixed

drug eruption In medicine, a drug eruption is an adverse drug reaction of the skin. Most drug-induced cutaneous reactions are mild and disappear when the offending drug is withdrawn. These are called "simple" drug eruptions. However, more serious drug eruptions ...

s, and

lupus erythematosus is a collection of autoimmune diseases in which the human immune system becomes hyperactive and attacks healthy tissues. Symptoms of these diseases can affect many different body systems, including joints, skin, kidneys, blood cells, heart, ...

Michaelis-Gutmann bodies

The concept of targetoid structures applies not only to macroscopic skin lesions but also to microscopic features. For instance, the Michaelis-Gutmann body, a characteristic histological finding in

malakoplakia Malakoplakia (from Greek ''Malako'' "soft" + ''Plako'' "plaque") is a rare inflammatory condition which makes its presence known as a papule, plaque or ulceration that usually affects the genitourinary tract. However, it may also be associated wit ...

, exhibits a targetoid or "bull's-eye" appearance under light microscopy. These intracellular and extracellular inclusions, composed of mineralized bacterial debris, illustrate how the targetoid pattern can manifest at both clinical and histopathological levels. Michaelis-Gutmann bodies are generally 1–10 μm in size and appear as laminated or targetoid basophilic inclusions containing iron and calcium salts. Under light microscopy, they often exhibit a concentric "bird's-eye" or "owl-eye" (targetoid) appearance due to a central

hydroxyapatite Hydroxyapatite (International Mineralogical Association, IMA name: hydroxylapatite) (Hap, HAp, or HA) is a naturally occurring mineral form of calcium apatite with the Chemical formula, formula , often written to denote that the Crystal struc ...

core. This targetoid structure results from mineralization of the matrix cores and the peripheral accumulation of phospholipids and microvesicles representing incompletely digested debris.

Examples

Examples of targetoid lesions include: * Target lesion * Targetoid hemosiderotic hemangioma * Targetoid Michaelis-Gutmann bodies * Targetoid

calcification Calcification is the accumulation of calcium salts in a body tissue. It normally occurs in the formation of bone, but calcium can be deposited abnormally in soft tissue,Miller, J. D. Cardiovascular calcification: Orbicular origins. ''Nature M ...

References

External links

Targetoid Michaelis-Gutmann bodies
- granuloma.homestead.com.
Targetoid nevus
- pbase.com. Dermatologic terminology Oncology {{Dermatology-stub}