Q: 28 year old male is admitted to hospital with shortness of breath. Lab. workup showed elevation of alkaline phosphatase. Further lab. inquiry for specific isozyme showed it of placental type. What is the diagnosis?

Answer:  Seminoma

In humans, alkaline phosphatase is present in all tissues but is particularly concentrated in intestine, liver, bone and the placenta.  Following are the alkaline phosphatase isozymes:

• ALPI – intestinal
• ALPL – liver/bone/kidney
• ALPP – placental

Placental alkaline phosphatase is elevated in seminomas and active form of Rickets.