Central scar dilemma: Oncocytoma versus RCC

Case courtesy: SDIC, Bangalore

Central stellate non-enhancing scar, has been linked characteristically to oncocytoma. But unfortunately,

1. It is seen only in 1/3rd of oncocytoma cases, and renal cell carcinoma can also show those scars quite often. 
2. This patient was 55 yr old, which is a perfect age group for oncocytoma, yet renal cell carcinoma too have incidences in this age group only. 
3. Lesion appears well-encapsulated, and exophytic, which favour oncocytoma, yet medially capsule doesn't appear quite regular, and lesion appears infiltrative. 
4. Renal vein thrombosis may be seen in both RCC and oncocytoma, although not seen in this case.

In nutshell, radiology can give some good input, yet differentiating both is difficult. 5% of resected renal tumours turn-out to be oncocytoma. Yet, I favour diagnosing these kind of masses as renal cell carcinoma, as treatment of these masses should be surgical resection. Considering stage I renal cell carcinoma, renal sparing surgery may be thought in both the cases. Post-operative histopathology may bring some relief to patient if any, and improve prognosis if proven oncocytoma. Pre-operative prognosis is indeterminate.

(Case courtesy: Sapthagiri digital imaging center, Bangalore)

Aqueductal stenosis. CSF flow study could have proven beneficial.

What observation apart from hydrocephalus favour aqueductal stenosis? 

Flow void across aqueduct on T2 sagittal images, and upward bowing of corpus callosum. Detailed evaluation (not included) showed a dysgenetic corpus callosum, with markedly deficient body of corpus callosum.

Considering a congenital cause, what other morphological finding could have been seen?

Aqueductal web/diaphragm is sometimes seen. I feel there is a thin aqueductal web, even in this case.

Treatment of aqueductal stenosis:
Third ventriculostomy +/- VP shunting.

(Case courtesy: Sapthagiri Digital Imaging Center, Bangalore)

Avascular necrosis of femoral head

Arlet Ficat staging

Stage 0 – Normal

Stage 1 – Only marrow edema

Stage 2- Geographic defect (As seen in this case)

Stage 3- Crescent sign and eventual cortical collapse (Subchondral crescent in case, although no collapse).

Stage4- Secondary degenerative changes.

This case may be labeled Stage 2, progressing to stage 3.

Mitchell staging

CLASS A: Fat (T1 bright T2 intermediate)

CLASS B: Blood (T1 bright T2 bright)

CLASS C: Fluid (T1 hypo T2 hyper)

CLASS D: Fibrosis (T1 hypo T2 hypo)

This case appears class A.

Which bone is most common location of AVN?

Femoral head.

This Indian patient was a chronic alcoholic, travelled recently from middle east, with no history of recent acute trauma. What could be a likely predisposition of AVN in this patient?

Alcoholism is commonly associated with AVN.

Can you specifically guess, which arterial supply may be have been interrupted?

Most common artery involved is ‘lateral epiphyseal artery’, probably in this case too. Anterolateral femoral head is most commonly involved by AVN.

Do you see a ‘double line sign’ in this case?

Yes, at most anterior aspect of involved region.

 

(Case courtesy: Sapthagiri digital imaging center, Bangalore)

Right PICA territory infarct, with probably long-segment disease involving right vertebral artery.

What is a serious complication of these kind of infarcts?

These infarcts may not be clinically evident, and usually present at a later stage. PICA territory infarcts with long-segment involvement may carry a poor prognosis, due to gradual progression in mass effect, and brainstem involvement with hydrocephalus due to territorial progression or mass effect. Many-a-times, it needs a decompression craniotomy.

In the given case, is there an evidence of lateral medullary syndrome?

Yes, right lateral medulla is involved.

Which cerebral artery is most variable in its course, origin and distribution?

PICA is most variable cerebral artery. Approx. 20% arise from extracranial vertebral artery. Approx. 10% arise from basilar artery. In 2% of cases, they are bilaterally absent.

MRI: Myths and truth

Recently, I came across a query from one the patients, “Is it safe to breast-feed after MRI? If no, then how long we should stop?” For the moment, question seemed weird to me, and tried to analyze magnetic susceptibilities of breast milk in my mind, but I was going nowhere. Being a radiologist, never heard of any such contra-indication. But yes, if at all, contrast is to be administered, there is a catch! So, I thought of clearing such myths which exist in our mind, when we go for MRI.

Myth 1: MRI gives a lot of radiation, and may cause undue illness.

Truth: MRI has nothing to do with radiation of any kind. I think we are confusing it with CT scan. It’s the CT scan which is a similar kind of machine and procedure, where we use radiation. MRI can never ever give a radiation, or cause any undue illness just due to the procedure. Sometimes, we do need to give a contrast injection, but it will be pre-informed, and will only be given after assessing renal status. In patients with renal failure of certain degree, contrast can cause reactions and undue illness. But, a non-contrast MRI, which is done more commonly, causes no harm of any kind to anybody.

Myth 2: Breast feeding after MRI is to be avoided for 24 hours.

Truth: There is absolutely nothing like that, and MRI is perfectly safe for breastfeeding mother as well as baby. It has no after-affects. In some cases, when we need to give contrast, then mother should express the breast milk before the study, and keep it for use during next 24 hours. Contrast may be secreted in breast milk. However, contrast won’t be needed in most cases to make the diagnosis. E.g. if you have back pain and need to find out if there is disc prolapse, there is no need of contrast. Even if contrast is needed, patient will be informed in advance, and they can prepare accordingly.

Myth 3: Oh! That black-hole machine, they will leave you in narrow hole in a dark room with nobody around and a lot of noise.

Truth: I do see people sweating before going for MRI and even during the procedure still, but it’s much rare these days. It’s more of pre-feeded notions, which bring fear. It’s usually a well-lit room these days, and the machines are getting wide-bored and sometimes, open MRI machines, where there is no hole at all. But, a machine with a hole has better resolution and gives good images. Technologist team can always see you, through the glass, and you can see him too. A buzzer will be given in your hand, which you can use in any emergency to call the technologist, and immediately stop the examination. Also, any of your friend or relative can sit with you through out the examination. A nice music would be played during the examination, and ear plug will be given to avoid the machine noise. Definitely, its not a fun-game, rather a diagnostic test, which you need urgently to figure out your disease, but there is nothing scary or eerie feeling about it. It can be the most pleasant test you will have.

Myth 4: I cannot have MRI, as I have a metal rod in my leg.

Truth: Almost all the metallic prosthesis or implants these days are MR safe.

However, these implants should not be there –

1. Pacemaker (however, MR safe pacemakers have also come now)

2. External hearing devices (should be taken out outside MRI room before the procedure)

3. Foley’s urinary catheter (especially one with temperature sensor to be avoided. Better to take it out before the procedure. However, there are ways to make it MR safe. http://www.mrisafety.com/safety_article.asp?subject=206 )

4. Penile implants (however, MR safe penile implants are available)

5. Pellets or bullets inside body or spine (better to avoid MRI if possible)

6. Transdermal patches (better to take it out before the procedure, and may be re-implanted, especially if they contain some metallic component like alumunium)

7. Cochlear implants

Which implants are safe:

1. Metal implants in hand, leg, shoulder etc. (Unless it was implanted some 20 yrs back!, when we had magnetic implants)

2. Intrauterine contraceptive devices including MIRENA

3. Artificial lens in eye

4. Denture

5. Screws and plates in spine

6. Prosthetic heart valves (they are mostly safe, but, indication of MRI should be justified)

7. Knee or hip replacement implants

8. I.V. cannula, central line or chemotherapy ports

09. Surgical sutures, especially if done 3 months back.

10. DJ stent

11. Guidewire

Please pre-inform the technician if you have these implants

However, all the information about any implant, will be asked before examination. But, please inform the technologist about these implants, so that he can take certain precautions during study

1. Permanent tattoos in body – sometimes, people may experience some itching or burning sensation, which should be pre-explained to the patient and patient should also inform immediately during the examination.

2. Body piercing jewellery – ideally, they should be removed before the examination. If not possible, then, they should be taped or glued to some fixed part o

TRUS guided biopsy: its simple, harmless and life-saver

Note: This blog is directed mainly to people who actually care about their health.
 
Recently I came across a 55 year old patient, a retired executive, who was having yearly regular check-ups. This time, he came for a MRI of spine, because he was experiencing some back pain. As I looked at the initial images of his MRI, I could see multiple metastases in vertebrae. There was no obvious mass (tumour) in his abdominal scan I did in morning. Prostate was measuring some 30 grams , okay for his age. I looked at his old papers, and only thing that struck me, was his last year PSA was 15 ng/ml (elevated not yet alarming as he was told). Just out of suspicion, I asked the clinician to get repeat PSA...It was whopping 110 now! Next day, I biopsied randomly from all sextants of prostate (TRUS guided), as I could not see any lesion yet. It proved to be prostate cancer.

Dictum is "you should always get TRUS guided biopsy if PSA is above 10 ng/ml, and if digital rectal examination is suspicious, even if PSA is above 4 ng/ml." And above all, whats the harm? whats the contraindication? and whats the radiologist dilemma? Almost all urologists agree with this dictum, but either patients get anxious, or radiologist is not confident enough. This arcane, grand terminology and explanation of procedure - TRUS guided biopsy...whoosh....putting a bulky rod into the rectum, and then a sharp needle over it, and firing many times.....not gonna do it.....is there a way out? Actually, the way out is much worse some times, as seen in the case I mentioned. And the procedure itself is not that traumatic,painful or risky as it seems.

I personally have done many biopsies (no accurate counts but may be close to hundred if not more), and have never ever experience any complications. Never did I witness any serious complications, done by any damn and first-timer radiologist. And almost hundred percent times, it has cleared the air between cancer or no cancer. Even if malignancy (cancer), it did pick at early stages and was well managed afterwards.

In my words, procedure is
 "We do a simple ultrasound of prostate, yes, by putting a probe inside rectum, but it is so well lubricated, it doesn't feel anything. Point is, it will only enter into the rectum, only if patient allows and relaxes, which means, in a painless situation. Else, radiologist would not able to push the probe itself. Its not like older days endoscopies, with a large tube pushed forcefully. Its a two-way thing, and needs some patient co-operation. Almost never did any patient refused to get this done while I was doing the procedure, which means its simple to accept.
Then, we use an accurately single-shot firing biopsy gun. Its not like, we are poking the needle again and again and shearing the hell out of you. Its one shot, like a bee-sting, and that too at a point, where you will never experience pain! Yes, biopsy is always taken when probe is above the dentate line. We can only feel pain if we are shot below this line. Above this line, there can never be any pain by nature of our body. So, its proven painless procedure. Bleeding, yes, when we are actually poking a needle, and that too a few times to get correct number of samples, it would bleed a bit. But, our body is so conditioned, that rectal bleeds of this nature in healthy men (procedure is always done when there is  normal clotting time, PT) would be almost immediately healed. I have never seen a person with continuous bleeding after procedure. In fact, I do it on out-patient basis many-a-times, and patient just walks out and never calls me back that he is having this or that. Though, I always call them back, and just trying to know if the procedure does cause any complications. Even if blood in urine or stool keeps coming, it can be handled with much ease."

There is simply no other way to prove that you definitely have a prostate cancer, or you have not. Biopsy is the only way to go. And last but not the least

PROSTATE CANCER IS THE MOST COMMON CANCER IN MOST COUNTRIES NOW.

Ectopic pregnancy: The grey zone of radiologist

Suspicion and strong instinctive clinical suspicion is the key to diagnosis of ectopic pregnancy. Its usually a combined effort of obstetrician and radiologist, which usually pinpoints the diagnosis. Serum B-HCG markers, which were introduced in early 1980s, can solve this dilemma much easily in almost all instances. However, for some reasons, confusion and lack of emergent management still persists in clinical practice. Few instances I have personally come across -
Case 1:
26 yr old 2 months pregnant female walks into emergency department in night with P/V bleeding. Emergency call was made to sonologist, who found a tiny gestation sac, and a luteal cyst, with no subchorionic collection or sac separation. Case was closed as early pregnancy, and patient was sent home. Patient returns back same very morning, almost fainting, pale in look, hypotensive on examination. Repeat ultrasound was done, which shows similar findings, with an irregular adnexal cystic lesion (discarded as luteal cyst in night) and dirty free fluid in pelvis. He pens down it as possible ruptured ectopic pregnancy, and reviews the gestation sac as 'pseudo-gestational sac'. Obstetrician sees the contradictory reports and does not believe the radiologist. She orders B-HCG, and here was committed a 'sheer crime'. Patient is deteriorating and B-HCG marker is taking its own time. Finally, the verdict comes, with B-HCG of 2500. Patient undergoes laparoscopy, and an ominous ruptured tube is staring at the surgeon, with blood almost in every pocket of abdomen.

Lessons 

• for radiologist - till you see a fetal pole, consider possibility of pseudogestation sac and always correlate with B-HCG. Also, have a close look at the luteal cyst, sometimes 'tubal ring' with 'ring of fire' can be seen.
• for obstetrician - always be suspicious of ectopic pregnancy, and never wait for too many reports if you think it is clinically ectopic. You can always close the laparoscopy wound, but avoid a rupture. One clue can create a suspicion, second can make you sure, don't wait for third one!

 Case 2:
29 year old female was not getting periods since last one year and was diagnosed with polycystic ovaries 6 months back, for which she is on weight-loss schedule. This time it had been 3 months since she got period. She got her urine pregnancy test done twice in last 2 months, and one two days back, all of them came negative. Gynecologist refers her to evaluate for PCOD. Radiologist saw thick endometrium, tiny follicles in ovaries, and some dirty fluid in pelvis. Just before finishing the examination and labelling it as classical PCOD, he was not sure what to say about this dirty fluid. There was no endometriotic cyst, he was having another cursory look, till he sees some weird soft tissue in left adnexa. He puts on doppler, which shows some vague color flow. Patient was not having any probe tenderness. This is what his report said,
"Heterogenous adnexal soft tissue lesion on left side and fluid with coarse internal echoes in pelvis - Possibilities include ectopic pregnancy, endometriosis or tubal inflammatory etiology. To be correlated with Serum B-HCG and MRI if needed."
Patient got her B-HCG done, and radiologist advised to just delay the MRI till B-HCG report comes. B-HCG came out to be 757 (?). Where do we stand now? Obstetrician felt like she is 'sitting on a bomb' and didn't want to wait for it to explode. She operated it immediately, and saw fiery red fallopian tube, with fimbrial abortion as she could see products of conception floating in pool of blood in pelvis. Rupture could be however avoided or rather contained.

Lessons

• for radiologist- suspicion of ectopic is almost always there! Just have a close look, may be some clue is lying somewhere, while you are rotating your torch (TVS probe) in dark woods.
• for gynecologist - Collect the clues, act at your instinct and at the earliest.

 Case 3
27 year old female visits to get an early pregnancy (1st trimester scan), and she had been having spotting since last 2 days. Its already 6 weeks, and radiologist is searching everywhere for the sac, and he sees mildly thick endometrium and thats it! No sac could be seen anywhere. Patient is wincing while the TVS probe is being rotated, not allowing to explore. Well, some pain is expected sometimes in TVS. Radiologist withdraws the probe, however he has limited explanation. He pens down something like this-
"Possibility of recent abortion, very early intrauterine pregnancy, and occult ectopic pregnancy - to be correlated with B-HCG". While patient is better, and gynecologist sends her home. B-HCG comes a magnanimous 10000 IU (!).
Obstetrician feels something fishy, may be she aborted, as we don't see a sac anywhere, and she goes to sleep. She doesn't know, she is 'sleeping on the bomb'. Bomb explodes the next morning, when a collapsed patient is being strolled down on a wheel-chair. And, she commits another crime, when she waits for another scan by a radiologist. Well, he does it and sees blood in pelvis, abdomen, everywhere...declares it as 'ruptured ectopic pregnancy'. Patient gets operated, a mass was also found somewhere in adnexa probably.

Lessons

• for radiologist - if patient is having pain, you may choose to withdraw the probe, however, convey a strong suspicion of ectopic in view of tenderness.
• for gynecologist - Don't wait till you pile up 'n' number of clues! Stick to the definition, "B-HCG >1000/1500, and no intrauterine gestation sac, thats it, that's what we call ectopic". Never sleep on this report.

All said and done, the mystery and confusion still prevails. Blamegame goes on, but its the patients who suffer.