It also sounds like it could imply secondary disease, but acquired disease can be primary disease. Acute disease
An acute disease is one of a short-term nature (acute); the term sometimes also connotes a fulminant nature
Chronic condition or chronic disease
A chronic disease is one that persists over time, often characterized as at least six months but may also include illnesses that are expected to last for the entirety of ones natural life. Congenital disorder or congenital disease
A congenital disorder is one that is present at birth. It is often a genetic disease or disorder and can be inherited. It can also be the result of a vertically transmitted infection from the mother, such as HIV/AIDS. Genetic disease
A genetic disorder or disease is caused by one or more genetic mutations. It is often inherited, but some mutations are random and de novo. Hereditary or inherited disease
A hereditary disease is a type of genetic disease caused by genetic mutations that are hereditary (and can run in families)
Iatrogenic disease
An iatrogenic disease or condition is one that is caused by medical intervention, whether as a side effect of a treatment or as an inadvertent outcome. Idiopathic disease
An idiopathic disease has an unknown cause or source. As medical science has advanced, many diseases with entirely unknown causes have had some aspects of their sources explained and therefore shed their idiopathic status. For example, when germs were discovered, it became known that they were a cause of infection, but particular germs and diseases had not been linked.
A hibernoma is a benign neoplasm of vestigial brown fat. The term was originally used by the French anatomist Louis Gery in 1914. Signs and symptoms
Patients present with a slow-growing, painless, solitary mass, usually of the subcutaneous tissues. It is much less frequently noted in the intramuscular tissue. It is not uncommon for symptoms to be present for years. Benign neoplasm with brown fat is noted. Diagnosis
Imaging findings
In general, imaging studies show a well-defined, heterogeneous mass, usually showing a mass which is hypointense to subcutaneous fat on magnetic resonance T1-weight images. Serpentine, thin, low signal bands (septations or vessels) are often seen throughout the tumor. Pathology findings
From a macroscopic perspective, there is a well-defined, encapsulated or circumscribed mass, showing a soft, yellow tan to deep brown mass. The size ranges from 1 to 27 cm, although the mean is about 10 cm. The tumors histologically resemble brown fat. There are four histologic types recognized, but one is the most frequently seen (typical). There is a background of rich vascularity. Lobular type: Variable degrees of differentiation of uniform, round to oval cells with granular eosinophilic cells with prominent borders, alternating with coarsely multivacuolated fat cells (pale cells). There are usually small centrally placed nuclei without pleomorphism. The cells have large cytoplasmic lipid droplets interspersed throughout.