AP Chest radiograph of a patient with a history of prostate cancer. Which classical sign is demonstrated in the vertebra and in which vertebra is it demonstrated ? Hint
Ans: Winking Owl sign Discussion Spinal metastases are common in oncology patients. One of the most reliable signs of osteolytic spinal metastases on conventional radiographs is the loss of vertebral pedicle contours on AP views of the thoracic or lumbar spine. This sign of the absent pedicle has also been termed the winking owl sign, where the missing pedicle corresponds to the closed eye, the contralateral pedicle to the other open eye, and the spinous process to the beak of the animal. You can imagine the spine looking like a stack of owl heads. In the image, the left pedicle of T9 (the left eye of T9) is not visible, suggesting destruction of the cortical bone of this pedicle. This is classically an osteolytic process like metastatic disease. This particular person had prostate cancer. How do you know it’s T9?: by counting ribs from the bottom. Credit to bb100..this required somebody really intelligent. Hats off Brother (Y)
Related Self Assessment Questions Question 1 of 3 A 72-year-old man with a diagnosis of prostate cancer was recently seen in the clinic for restaging and re-evaluation. His bone scan showed development of widespread osseous metastases and his PSA was rising. He was started on leuprolide acetate, a gonadotropin releasing-hormone (GnRH) agonist. He now returns to the clinic complaining of new severe mid-thoracic back pain, which is worse with recumbency and worse with Valsalva maneuver. He also reports that he has a brief but intense electric shock sensation in his lower extremities when he bends over to tie his shoes. On physical exam, he had localized tenderness over the mid-thoracic spine, but his motor strength, sensation, and deep tendon reflexes are all intact. What is the most appropriate next step? A. Obtain an MRI of the thoracic spine. B. Refer for neurosurgical evaluation. C. Initiate radiation therapy to the affected thoracic spine. D. Start the patient on scheduled narcotics for relief of the back pain and follow up in 1 week. E. Stop the leuprolide and schedule the patient to return to clinic in 1 week for re-evaluation. The answer is A. Question 2 of 3 A 72-year-old man with a diagnosis of prostate cancer was recently seen in the clinic for restaging and re-evaluation. His bone scan showed development of widespread osseous metastases and his PSA was rising. He was started on leuprolide acetate, a gonadotropin releasing-hormone (GnRH) agonist. He now returns to the clinic complaining of new severe mid-thoracic back pain, which is worse with recumbency and worse with Valsalva maneuver. He also reports that he has a brief but intense electric shock sensation in his lower extremities when he bends over to tie his shoes. On physical exam, he had localized tenderness over the mid-thoracic spine, but his motor strength, sensation, and deep tendon reflexes are all intact. What is the most important prognostic factor regarding this patient's ultimate neurological outcome? A. patient's age and co-morbid conditions at time of diagnosis B. degree of neurological impairment at time of diagnosis and initiation of therapy C. number of vertebral bodies affected by metastatic disease D. tumor sensitivity to androgen stimulation or inhibition E. patient's overall functional status before the development of the spinal cord injury The answer is B. Question 3 of 3 A 72-year-old man with a diagnosis of prostate cancer was recently seen in the clinic for restaging and re-evaluation. His bone scan showed development of widespread osseous metastases and his PSA was rising. He was started on leuprolide acetate, a gonadotropin releasing-hormone (GnRH) agonist. He now returns to the clinic complaining of new severe mid-thoracic back pain, which is worse with recumbency and worse with Valsalva maneuver. He also reports that he has a brief but intense electric shock sensation in his lower extremities when he bends over to tie his shoes. On physical exam, he had localized tenderness over the mid-thoracic spine, but his motor strength, sensation, and deep tendon reflexes are all intact. What is the most likely explanation for the rapid onset of back pain and neurological difficulty after the initiation of leuprolide? A. The patient's tumor was likely androgen-independent and so did not respond to hormonal therapy, with rapid progression of his cancer. B. The patient likely experienced vasomotor symptoms such as hot flashes and discontinued the therapy, leading to the tumor progression. C. The GnRH agonist produced a transient rise in serum testosterone, causing a "tumor flare." D. The patient's response was an unpredictable idiopathic drug reaction. E. There is no plausible mechanism by which the medication could cause the development of spinal cord compression, and so it is likely unrelated to the patient's symptoms. The answer is C. EXPLANATION: The patient has symptoms of spinal cord compression and needs an urgent MRI to establish the diagnosis. Spinal cord compression usually develops when patients have metastases to the vertebral body with epidural extension of the tumor, displacing the underlying thecal sac, and causing cord edema and injury. Patients with cord compression usually experience new or worsening pain symptoms days or weeks before the development of motor weakness below the level of compression. Loss of sensation and loss of bowel or bladder control occur even later. Clues that the pain symptoms may represent cord injury include pain that is worse with recumbency or Valsalva and the occurrence of Lhermitte's sign, an electric sensation down the back and into the extremities with extension or flexion of the neck or spine. Initiation of therapy, such as radiation therapy or neurosurgical intervention, might be necessary later but would be premature before the diagnosis is established with an imaging study. If the patient's history or physical exam suggests spinal cord compression, initiation of corticosteroids should be started immediately while diagnostic imaging is pending. Pain control with adequate narcotic analgesia is important and may be instituted while the appropriate diagnostic studies are being obtained. Delay of 1 week would be inappropriate due to the urgent nature of the problem and risk of neurological compromise. The patient's neurological status at the time of diagnosis is the most important prognostic factor: 75”“80% of patients who are ambulatory at the time of diagnosis will retain locomotion. But, if already paraplegic, only 10% will regain the ability to walk. While this patient appeared neurologically intact, the development of neurological deficits can progress over a period of days, making rapid diagnosis and institution of appropriate therapy such as corticosteroids and radiotherapy an urgent consideration. Other factors such as age, presence of co-morbid medical conditions, functional status, and tumor androgen-sensitivity are important to the patient's overall cancer prognosis. Standard therapy for patients with metastatic prostate cancer is to block testosterone action or decrease its production to inhibit tumor stimulation. Surgical orchiectomy would be the most definitive anti-androgen therapy, but most patients favor medical therapy. Leuprolide is a gonadotropin-releasing hormone (GnRH) analogue, which produces a transient rise in luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which is then followed by downregulation of pituitary receptors and subsequent "chemical castration." The transient LH and FSH rise causes an initial rise in serum testosterone concentration, and may produce a "tumor flare," with worsening of symptoms during the first 1”“2 weeks of therapy, including bone pain and bladder outlet obstruction, and for patients with epidural tumor, can precipitate spinal cord compression. When the level of testosterone falls, patients may experience side effects such as testicular atrophy, loss of libido, and vasomotor symptoms. (Y)
