Disease with two distinct phases
A biphasic disease is a disease which has two distinct phases or components. In clinically biphasic diseases, the phases are generally chronologically separated. In histopathologically biphasic tumors (also called biplastic tumors), there is neoplastic tissue which contains two different cellular elements.
Examples
Clinically biphasic diseases
| Disease |
Typical first phase |
Typical second phase
|
| European (or "Western") subtype of tick-borne encephalitis virus
|
Relatively mild flu-like illness |
Affecting some cases, generally presenting with high fever and neurologic disease (encephalitis), meningitis and/or meningoencephalitis)
|
| Leptospirosis
|
4–9 days of abrupt onset of flu-like illness |
Fever, jaundice, abdominal pain and diarrhoea. Organ failure in severe cases.
|
| Anthracosis
|
After approximately 4 days, patients develop flu-like illness with fever, nonproductive cough, and myalgias lasting approximately 4 days |
Without timely treatment, a second fulminant phase follows, characterized by hypotension and dyspnea. This phase may progress to death within 24 hours of its onset
|
Tumor biplasia
| Disease |
Cellular elements
|
| Fibroadenoma
|
Epithelium |
Stroma
|
| Ceruminous adenoma
|
Inner luminal secretory cells |
Myoepithelial cells
|