শেষ আপডেট: আগস্ট 30, 2026
Angiomyolipoma (AML) is one of the commonest incidental findings I discuss in the clinic. It is usually picked up at a health check-up, which means the patient arrives having already been told there is a tumour in the kidney — and is understandably alarmed by the time we meet. So let me start where the conversation always starts.
Angiomyolipoma is a benign renal tumour. It is reported in 0.2–0.6% of the general population and is most common in middle-aged women. Its causes fall into two groups.

- Sporadic — arising on its own with no identifiable cause. This accounts for 80% of cases.
- Genetic — associated with tuberous sclerosis complex (TSC) or pulmonary lymphangioleiomyomatosis (LAM). This accounts for 20% of cases.
That second group is worth pausing on, because it changes the conversation. If several angiomyolipomas are found, if they are in both kidneys, or if the patient is young, the question of an underlying genetic condition is a real one rather than a formality — and it matters, because such conditions involve more than the kidney, run in families, and are followed differently. If your scan describes more than one, ask about it.
Around 85% of angiomyolipomas cause no symptoms at all and are found incidentally on imaging done for another reason. The remaining 15% present with symptoms.

Symptoms of a symptomatic angiomyolipoma
- Spontaneous tumour haemorrhage
- স্পষ্ট ফ্ল্যাঙ্ক ভর
- পার্শ্বদেশ ব্যথা
- Blood in the urine
- মূত্রনালীর সংক্রমণ
Bleeding: the one thing to take seriously
Almost everything about this diagnosis is reassuring, and I do not want the reassurance to bury the one situation that is not. An angiomyolipoma is packed with abnormal blood vessels, and if one of them gives way the bleeding happens behind the abdomen where there is nothing to compress it. That can go from uncomfortable to dangerous quickly — it is the reason larger tumours get treated at all.
If you have a known angiomyolipoma, go to an emergency department the same day — in Thailand call 1669 — for any of these:
- Sudden severe pain in the flank, side or abdomen, particularly if it came on without warning
- Feeling faint, dizzy on standing, unusually pale, sweaty, or with a racing heartbeat — these are signs of blood loss, and they can appear before the pain becomes severe
- Heavy visible blood in the urine, particularly with clots
- New or worsening flank pain that is not settling, even if it is not severe
Tell whoever assesses you that you have a known angiomyolipoma and which side it is on. It changes what they look for immediately, and it is easily missed if nobody says it. This is also a good reason to keep a note or a photo of your scan report on your phone.
How it is diagnosed
Angiomyolipoma can be diagnosed on imaging alone, which is unusual for a tumour. That is because it has a distinctive composition — it contains fat. Once imaging demonstrates a renal tumour containing fat, the diagnosis is effectively made, and no biopsy is needed.

- আল্ট্রাসাউন্ড — the most commonly used modality. Cheap, no radiation, widely available; but operator-dependent and less accurate for small lesions.
- Non-contrast CT — the gold standard, giving a definitive diagnosis; but involves radiation and costs more.
- এমআরআই — an accurate alternative; but slower, expensive, and contraindicated in patients with certain metallic implants.
- Percutaneous biopsy — rarely needed, and reserved for atypical cases, because it carries a risk of bleeding.
The words “atypical cases” are doing real work in that last line, so let me unpack them. The whole diagnosis rests on seeing fat, and a minority of angiomyolipomas contain so little fat that imaging cannot demonstrate it. Those look, on a scan, very much like a kidney cancer — and that is precisely why a lesion which does not show fat is not simply assumed to be a benign angiomyolipoma. It gets investigated properly. If you have been told your tumour is “probably” an angiomyolipoma rather than definitely one, this is usually why, and it is worth asking whether further imaging or a biopsy is planned.

Why 4 cm is the number that matters
The evidence supports reassurance and observation for an angiomyolipoma under 4 cm — no intervention is required. Above 4 cm, the risk of spontaneous rupture and bleeding rises, and treatment enters the discussion. The options are active surveillance, embolization, thermal ablation and surgery; embolization is generally the preferred first-line intervention, with surgery reserved for cases where malignancy cannot be excluded.
Read that as a threshold for a conversation rather than a trigger for an operation. Passing 4 cm does not mean something must now be done; it means the balance between watching and treating is no longer obvious, and depends on your particular tumour, your symptoms, whether you can get to a hospital quickly if something happened, and what you yourself would rather live with. Plenty of people above that size are still simply watched. Ask what your own numbers are and what your urologist is weighing — this is a decision you should be part of rather than have handed to you.

The message I want every patient to leave with is this: angiomyolipoma is a benign tumour, and in most cases an active surveillance programme is all that is needed. Intervention is the exception, not the rule — but knowing what bleeding feels like, and going straight to an emergency department if it happens, is the part of the plan that sits with you rather than with your doctor.
প্রায়শই জিজ্ঞাসিত প্রশ্ন
প্রশ্ন ১: কিডনির অ্যাঞ্জিওমায়োলাইপোমা কি ক্যান্সার?
না। অ্যাঞ্জিওমায়োলাইপোমা (AML) একটি সৌম্য (ক্যান্সারবিহীন) কিডনি টিউমার। এটি চর্বি, মসৃণ পেশি এবং রক্তনালী দিয়ে গঠিত এবং এটি ম্যালিগন্যান্ট নয়। তবে, বড় আকারের AML-এর ক্ষেত্রে স্বতঃস্ফূর্ত ফেটে যাওয়া ও রক্তক্ষরণের ঝুঁকি থাকে, যে কারণে ৪ সেন্টিমিটারের বেশি আকারের টিউমারের জন্য নিয়মিত পর্যবেক্ষণ এবং কখনো কখনো হস্তক্ষেপের পরামর্শ দেওয়া হয়।
প্রশ্ন ২: কিডনির অ্যাঞ্জিওমায়োলাইপোমার কারণ কী?
In 80% of cases, angiomyolipoma occurs sporadically with no identifiable underlying cause. The remaining 20% are associated with genetic conditions, primarily tuberous sclerosis complex (TSC) or pulmonary lymphangioleiomyomatosis (LAM). AMLs are most commonly found in middle-aged women, though they can occur in both sexes. Multiple angiomyolipomas, tumours in both kidneys, or a diagnosis in a young patient all raise the possibility of an underlying genetic condition and are worth asking about.
প্রশ্ন ৩: অ্যাঞ্জিওমায়োলাইপোমার কখন চিকিৎসা প্রয়োজন হয়?
AMLs smaller than 4 cm can generally be safely managed with active surveillance and regular imaging follow-up. Above 4 cm the risk of spontaneous rupture and serious haemorrhage rises and treatment enters the discussion — but crossing that size is a reason to weigh the options, not an automatic instruction to intervene, and many patients above it continue to be watched. Where treatment is chosen, embolization is the preferred first-line minimally invasive option, with surgery reserved for cases suspicious of malignancy.
প্রশ্ন ৪: অ্যাঞ্জিওমায়োলাইপোমা কীভাবে নির্ণয় করা হয়?
AML can be diagnosed by imaging alone due to its characteristic fat content. Non-contrasted CT scan is the gold standard, as it can reliably detect fat within the tumor. Ultrasound is widely used at health check-up clinics as an initial screening tool, while MRI is an alternative for patients who cannot undergo CT. Percutaneous biopsy is rarely needed and reserved for atypical cases — most often a lesion containing too little fat for imaging to demonstrate, which can look like a kidney cancer and therefore has to be investigated rather than assumed benign.
প্রশ্ন ৫: অ্যাঞ্জিওমায়োলাইপোমা কী কী উপসর্গ সৃষ্টি করে?
Approximately 85% of AMLs are asymptomatic and discovered incidentally during routine health check-up imaging. The remaining 15% may present with symptoms including flank pain, a palpable flank mass, bloody urination, urinary tract infection, or spontaneous tumor hemorrhage.
Q6: What does bleeding from an angiomyolipoma feel like, and what should I do?
Typically sudden severe pain in the flank, side or abdomen, coming on without warning. Because the bleeding occurs behind the abdomen where nothing compresses it, blood loss can become significant, so feeling faint, dizzy on standing, unusually pale or sweaty, or noticing a racing heartbeat matters as much as the pain — and those signs can appear before the pain is at its worst. Heavy visible blood in the urine, especially with clots, is also a reason to act. Go to an emergency department the same day rather than waiting for an appointment; in Thailand you can call 1669. Tell whoever assesses you that you have a known angiomyolipoma and which side, because it changes what they look for immediately.
Q7: Can I discuss an angiomyolipoma by video consultation?
Yes, and it suits this situation well, because the main task is reading the imaging report you already have and agreeing a plan. Bangkok Hospital Headquarters offers a Telemedicine service, arranged in advance by email to the Urology department at bhquro@bdms.co.th. Send the actual radiology report rather than a summary, since the exact wording — whether fat was demonstrated, the size, how many lesions, which side — is what determines the advice. Samitivej Sriracha is in-person only, booked through the Urology department line 088-022-1445. Sudden severe pain, faintness or heavy bleeding should never wait for a video appointment.
আপনাকে যদি বলা হয়ে থাকে যে আপনার কিডনি টিউমার বা অ্যাঞ্জিওমায়োলাইপোমা আছে এবং আপনি বিশেষজ্ঞের মূল্যায়ন চান, তাহলে ডাঃ সোআরাবী বীরাসোপোন ব্যাংকক হসপিটাল হেডকোয়ার্টার্স-এ পরামর্শ প্রদান করেন। পরামর্শ বুক করুন. Appointments at Samitivej Sriracha Hospital can be arranged by calling the Urology department on 088-022-1445. Questions about the cost of a consultation, scan or procedure should go to the hospital directly — for Bangkok Hospital, by email to bhquro@bdms.co.th.
Reference
- Review of renal angiomyolipoma: presentation, diagnosis and management. PubMed 30039053
দাবি পরিত্যাগ This content is written and reviewed by Dr. Soarawee Weerasopone, a board-certified urologist at Bangkok Hospital Headquarters. It is intended for educational purposes only and does not constitute medical advice, and it cannot substitute for a reading of your own imaging report. No medical advice, diagnosis or prescription is provided through personal messaging channels or social media. Always consult a qualified healthcare professional before starting any medical treatment. In an emergency, attend the nearest emergency department — in Thailand the emergency number is 1669.
মেডিকেল লেখা এবং পর্যালোচিত: ডাঃ সোয়ারাউই উইরাসোপোন (ডাঃ পম) — বোর্ড-সার্টিফাইড ইউরোলজিস্ট, ব্যাংকক হাসপাতাল হেডকোয়ার্টার্স, ২০১৬ সাল থেকে ইউরোলজিক্যাল চিকিৎসায় নিয়োজিত। ফেলোশিপ: রোবোটিক সার্জারি, চ্যাং গুং মেমোরিয়াল হাসপাতাল, তাইওয়ান (২০১৯) · অবজার্ভারশিপ: এন্ডোইউরোলজি, জুনতেন্দো ইউনিভার্সিটি হাসপাতাল, টোকিও (২০২২) · রিসার্চ স্কলার ও ক্লিনিক্যাল অবজার্ভার, স্কট ডিপার্টমেন্ট অফ ইউরোলজি, বেলর কলেজ অফ মেডিসিন, ইউএসএ (২০২৫–২০২৬)।.

Dr. Soarawee Weerasopone (Dr. Pom) is a board-certified urologist at Bangkok Hospital Headquarters, specializing in Men’s Health, Robotic Surgery (da Vinci Xi) and Kidney Stone treatment. He is currently a Research Scholar and Clinical Observer at the Scott Department of Urology, Baylor College of Medicine (2025–2026), under Prof. Mohit Khera. He completed a Robotic Surgery Fellowship at Chang Gung Memorial Hospital, Taiwan (2019) and an Endourology Observership at Juntendo University Hospital, Tokyo (2022).

