Question

Bobby, a 72-year-old retired male went to his doctor, complaining of leg pain that started in his lower back, ran across the side of his thigh and over the front of his knee. Next, he developed pain that radiated from his back to his front at the chest through the level of his nipples and also at the umbilicus.

A physical and laboratory tests showed hard nodule on his prostate and an elevation in several of the blood tests. His PSA (prostate specific antigen), an enzyme secreted by normal prostate tissue was very high. Alkaline phosphatase was also elevated, an indication of bone involvement.

A bone scan was ordered to visualize the bone involvement.

Usually prostate cancer's growth is initially influenced by the presence of testosterone. If testosterone is removed by castration, the cancer will often shrink for some period of time before the remaining fraction of testosterone-independent cancer cells grow.

Bobby was not interested in castration and asked if there was another form of treatment. He was treated was a single shot of a drug which is slowly released into the body over a three month time period. Within that time the patient noticed marked relief in his pain.

Why would the scan show bone abnormalities? What would cause it?

Answer 1

This is a case of prostate cancer which has metastasized to the bones. The clinical history of 72 years old male named Bobby with a hard nodule on his prostate gland and lower back pain radiating to the thighs and knee as well back pain radiating to the chest along with elevation of prostate specific antigen (PSA) and serum alkaline phosphatase in the blood count points towards the diagnosis of a prostatic cancer metastasized to the bones.

Prostate gland is an important gland of the male reproductive system which helps in the formation and secretion of seminal fluid. Cancer developing in the cells of prostate gland is prostatic cancer. A nodule is appreciated on the physical examination which suggests a prostatic tumour along with elevation of prostate specific antigen (PSA) in the blood which is an enzyme normally secreted by the prostate but elevated in prostatic tumour. Prostate cancer generally affects elderly males over the age of 60 years.

Prostate cancer generally spreads to the bones through bloodstream by invading the blood vessels. Hence bone scans in this patient show abnormalities as the prostate cancer has metastasized to the bones. Due to the metastatic bone lesions from the primary cancer in the prostate gland, the serum alkaline phosphatase enzyme which is a marker of bone activity has also increased. Thus, the primary cancer in the prostatic gland of 72 years old patient named Bobby has caused the bone abnormalities (due to metastasis from prostate cancer) which is evident in his bone scans.