Imagine this. A young teenager, 17, years old, who is fully developed. Now imagine this, the same teenager has a fully developed extra set of limbs and a pelvis. That extra set of pair is attached with chest artery. But, how can this happen?

While it is extremely rare, and has a chance of less than one case occurring per 100,000 births. Such things do happen. This is called parasitic twin.

What Is A Parasitic Twin?

It is an extremely rare type of cojoined twin where a baby is born with an underdeveloped twin attached to its body. This condition is also known as vestigial twins. The condition is very closely related to conjoined twins, where babies are connected at birth and share organs. However, the main difference is that in conjoined twins, there are two developed babies, whereas in parasitic twins, only one is fully developed, other one is underdeveloped and non functional.

In such a case, the twin who is developed is medically known as the autositic or the dominant twin. The dominant twin is healthy in most aspect but may have extra tissue, organs, or limbs from the parasitic twin.

The parasitic twin may be attached with the dominant twin through several places. The common joints are at the head, torso, chest, pelvis, buttocks, or back. In these cases, the parasitic twin is not alive and they die either in the womb or during the childbirth.

Doctors Remove Parasitic Twin

Now, let's go back to the case we referred to, where a young teenager had an extra pair of limbs attached to chest. The teenager who has not been named is from Uttar Pradesh's Unnao neighbourhood, and was treated in AIIMS, Delhi. The team of doctors successfully removed the extra set of limbs from his body.

Dr Asuri Krishna, who led the team of specialist who surgically removed the extra limbs told the BBC that only 40 to 50 cases of parasitic twins have been documented in world medical literature, and in those cases, the surgery had been attempted on children. The doctor said that without much medical literature to guide them, the team of doctors depended on "intuition, skill and knowledge".

The doctor shared that the child had two fully formed legs, buttocks and external genitalia, which weighed around 15kg "protruding from his abdomen".

How Was The Surgery Performed?

The doctor shared that first they identified how interconnected the parasitic and host twins were. The doctors took scans and found that parasitic twin was attached to the teen's breastbone. The blood was being supplied from a vessel in his chest. However, "there wasn't much connection with other main organs like the liver or kidneys," said Dr Krishna. The team also found a large cyst in the teen's abdomen.

Then the surgery was performed in two stages. In the first stage, the parasitic twin was removed. Then the cystic mass was extracted from the surrounded area. The entire surgery was completed in two and a half hours and the team of doctors included radiologists, anaesthetists, and plastic surgeons.

The biggest challenge was when the teen's blood pressure dropped as 30 to 40% of his blood flowed to the parasitic twin, however, the doctors were prepared for it and they stabilized him.

Pope Leo XIV’s lung cancer diagnosis has raised questions about whether a lung nodule always signals cancer.

The 71-year-old pontiff announced in a post on X this week that doctors had detected a small, localized lung nodule during medical examinations. The nodule was detected at a very early stage, and doctors recommended surgery to remove it.

According to Vatican News, surgeons at Gemelli Hospital removed the lower lobe of his right lung using a video-assisted technique. Examination of the tissue confirmed lung adenocarcinoma, the most common subtype of non-small cell lung cancer (NSCLC), accounting for roughly 40% of lung cancer cases.

“An intraoperative histological examination confirmed the diagnosis of lung adenocarcinoma, as suspected from the preoperative examinations,” the statement said.

But does finding a lung nodule always mean cancer? HealthandMe spoke to experts to understand which nodules need further investigation and what warning signs to watch for.

What Is a Lung Nodule?

Also read: Pope Leo XIV Will Undergo Lung Nodule Surgery: When Does Removal Become Necessary

A lung nodule is a small, localized spot in the lung, usually detected during a chest X-ray or CT scan. Most are benign, but some may indicate early lung cancer.

Dr Dipanjan Panda, Senior Consultant, Medical Oncology, Indraprastha Apollo Hospital, Delhi, told HealthandMe, that lung nodules can develop for several reasons, including infections, inflammation and, in some cases, cancer.

Does a Lung Nodule Mean Cancer?

Doctors assess a nodule’s size, shape, density and growth, along with the patient's age, smoking history and other risk factors. Depending on these findings, they may recommend follow-up CT scans, PET-CT imaging or a biopsy.

“A lung nodule is not synonymous with cancer. Most nodules are benign, often related to previous infections or scarring. Their size, appearance, growth, and the patient’s risk factors determine whether surveillance with repeat CT, PET-CT, or biopsy is needed. The key is appropriate risk assessment, not panic or unnecessary testing,” Dr Karn Mehra, Senior Consultant and Unit Head, Advanced Lung Failure and Transplant Pulmonologist, Fortis Hospital, Manesar, told HealthandMe.

When Should You Worry About A Lung Nodule?

Read More: Lung Nodule on CT Scan? Doctors Explain When You Should Worry

Dr Raajit Chanana, Director and Senior Consultant, Medical Oncology, Dharamshila Narayana Superspeciality Hospital, Delhi, highlighted several factors that may raise concern about malignancy:

• Size: Larger nodules generally carry a higher risk of malignancy.
• Growth: An enlarging nodule warrants further evaluation, while stability over time can be reassuring.
• Appearance: Irregular or spiculated edges are more concerning than smooth, well-defined borders.
• Smoking history: Current and former smokers face a higher risk of lung cancer.
• Personal and environmental factors: A previous cancer diagnosis, family history of lung cancer, and exposure to asbestos or radon may increase concern.
• Persistent cough, coughing up blood, unexplained weight loss, chest pain or breathlessness should prompt medical evaluation.

Can Lung Cancer Affect Non-Smokers?

Although tobacco remains a major risk factor, lung cancer can also develop in people who have never smoked.

Dr Mehra noted that lung cancer in never-smokers is increasingly being recognized, including among younger adults. Air pollution, occupational exposures and genetic susceptibility may also contribute to the risk.

However, living in a polluted city alone does not justify annual CT scans. Screening should follow established risk criteria, particularly those based on age and smoking history. Low-dose CT can detect early lung cancer in eligible high-risk individuals, while indiscriminate scanning can lead to radiation exposure, false-positive results and unnecessary procedures.

What Happens After a Lung Cancer Diagnosis?

READ: Dry Cough, Breathlessness May Not Always Be Asthma — Could It Be ILD?

Once lung cancer is confirmed, doctors determine its subtype, stage and molecular profile to guide treatment. Depending on these findings, treatment may include surgery, radiotherapy, targeted therapy, immunotherapy or chemotherapy.

For nodules not confirmed as cancer, management depends on their size, appearance, growth and the patient's risk factors. Small, low-risk nodules may require periodic CT scans, while suspicious ones may need further imaging or a biopsy. Not every nodule requires an invasive procedure.

Why Is Follow-Up Important?

“A lung nodule is not a cancer diagnosis, but it should never be ignored. Completing recommended follow-up scans is crucial. Quitting smoking remains one of the most effective ways to reduce lung cancer risk. Long-term smokers aged 50 and above should discuss whether they qualify for annual low-dose CT screening,” Dr Chanana said.

Short-term exposure to air pollution may increase the risk of hospitalisation for several serious health conditions, including cancers and mental disorders, according to a new landmark multicountry study published in The Lancet Planetary Health.

Researchers analysed 346.5 million hospitalisation records from 949 communities across six countries and territories, which included Australia, Brazil, Canada, Chile, New Zealand and Taiwan.

The study examined the relationship between short-term exposure to fine particulate matter (PM2.5) and hospital admissions between 2000 and 2019.

The findings revealed that every 10 micrograms per cubic metre (μg/m³) increase in PM2.5 concentration was associated with an 8% higher risk of hospitalisation from any cause. It was the strongest for malignant neoplasms, or cancers, followed by mental disorders.

The researchers also found that the increased risks associated with short-term exposure could persist for up to 21 days.

Hospital Admissions Related To Cancer And Mental Health Increased

Also read: Can Delhi’s Air Pollution Increase GI Cancer Risk? Doctors Report Patients As Young As 15

Among the disease categories examined, malignant neoplasms showed the strongest association with short-term PM2.5 exposure, with a 10.8% higher risk of hospitalisation for every 10 μg/m³ increase in particulate matter concentration.

It was followed by mental disorders, which showed a 10% higher risk. Other neoplasms were linked with a 9.6% increase, while nervous system diseases showed an 8.5% increase.

Respiratory diseases, that were commonly prevalent with air pollution, showed a 6.7% increase in hospitalisation risk.

These findings suggest that the health consequences of polluted air may not just be limited to lungs. They could affect people with a wide range of medical conditions.

However, the researchers assessed hospital admissions, not the occurrence of new diseases. Hence, they found that increases in PM2.5 exposure could increase the likelihood of hospitalisation among people affected by these conditions.

Decline In Hospitalisation Risks

Also read: Delhi Smog: Can You Really Tackle Pollution Season With An N95 Mask And Air Purifier?

The researchers found that hospitalisation risks related to pollution were lower during 2010-2019 than in 2000-2009. Using the World Health Organization's daily PM2.5 guideline of 15 μg/m³ as a reference, the estimated proportion of hospitalisations due to exposure declined from 8.9% to 3.9% between the two decades.

Despite this improvement, the associations remained significant across all disease categories. The study had limitations, including substantial differences in effects across different countries and territories. Its findings also cannot automatically be generalised to regions that were not included, including India.

The researchers concluded that reducing PM2.5 exposure remains an important public health measure to lower hospitalisation risks. Cleaner transport, stricter industrial emission controls and lower reliance on polluting fuels could help limit exposure and the significant health burden that comes with it.

The researchers also said that the effects of short-term PM 2.5 exposure on hospital admissions could persist for up to 21 days after exposure.

Effects Of PM2.5

PM2.5 refers to fine particulate matter measuring 2.5 micrometres or less in diameter. These particles can come from vehicle exhaust, industrial emissions, construction activities, power generation and the burning of fuels and biomass.

Because of their small size, PM2.5 particles can penetrate deep into the lungs, with some components entering the bloodstream. Exposure can trigger inflammation and oxidative stress, potentially affecting multiple organs.

Despite the observation, the study does not prove that short-term exposure to air pollution increases the risk of serious diseases like cancer. Stronger air-quality monitoring, improved cancer registries and studies linking data with clinical results could help researchers assess whether pollutants are associated with specific cancer types.

Studies would also need to account for other risk factors and differences in exposure across populations.

India faces a substantial hepatitis C burden, with the World Health Organization (WHO) estimating that 5.5 million to 12 million people are living with chronic hepatitis C virus (HCV) infection.

Untreated chronic HCV infection can lead to liver scarring, cirrhosis and liver cancer. Could shortening treatment by four weeks help more patients access a cure?

A multi-center trial led by researchers from the Indian Council of Medical Research (ICMR) found that an eight-week course of a commonly used antiviral combination was as effective as the standard 12-week regimen in patients without cirrhosis. Published in The Lancet, the findings could have implications for treatment costs and access to care.

The treatment combines sofosbuvir (400 mg) and velpatasvir (100 mg), two direct-acting antivirals that target the hepatitis C virus.

What Did The Indian Trial Find?

Also read: Punjab To Start Screening For HIV, Hepatitis B & C At De-Addiction Centres

The RESOLVE trial, led by researchers from Sanjay Gandhi Postgraduate Institute of Medical Sciences (SGPGIMS), Lucknow, evaluated whether eight weeks of sofosbuvir and velpatasvir could match the effectiveness of the standard 12-week course.

The trial enrolled 880 patients without cirrhosis across five publicly funded hospitals in Lucknow, New Delhi and Varanasi. Half received the combination for eight weeks, while the other half received it for 12 weeks.

Among participants who completed treatment and follow-up, 98.8% in the eight-week group achieved a sustained virological response, compared with 99% in the 12-week group. This means the virus remained undetectable after treatment, indicating a cure.

The researchers found that the shorter regimen was non-inferior to the standard course, meaning it was not less effective beyond the trial's prespecified statistical margin.

The study also reported no drug-related serious adverse events or treatment discontinuations due to adverse events.

How Shorter Treatment Help Reduce Hepatitis C Burden In India?

Direct-acting antivirals transformed hepatitis C treatment nearly a decade ago, making it possible to cure most patients with relatively few side effects. However, treatment costs and access remain important considerations for large public health programmes.

A 12-week course of sofosbuvir and velpatasvir costs approximately ₹15,000. Shortening treatment by four weeks could save around ₹5,000 per patient.

If adopted for a population of 60 lakh people requiring treatment, the shorter regimen could potentially save ₹3,000 crore. However, these are projected savings, and the actual impact would depend on patient eligibility, treatment costs and adoption in clinical practice.

Who Can Receive The Shorter Treatment?

The findings apply to patients without cirrhosis, as the trial excluded those with the condition. Patients with cirrhosis may require different treatment approaches depending on the severity of their liver disease and other clinical factors.

The trial's results do not mean that everyone with hepatitis C can switch to an eight-week course. Further evaluation and changes to relevant clinical guidance may be needed before the shorter regimen becomes routine practice.

Patients should consult their treating physician before making any changes to their prescribed treatment.

How Does Hepatitis C Spread?

Hepatitis C can cause illness ranging from mild infection to serious, long-term liver disease. Although some acute infections resolve spontaneously, chronic infection can progress to cirrhosis and hepatocellular carcinoma, a type of liver cancer.

The virus can spread through infected blood, including via shared needles and unscreened blood transfusions.

Perinatal transmission is an important route of HCV acquisition in children. Early detection can help identify infected infants and ensure appropriate follow-up.