Dr. Kumar’s realization hit him like a bolt of lightning. This was no tumor, but a malformed, parasitic twin. The discovery filled him with an odd cocktail of emotions; he was struck with awe, bewilderment, and a chilling sense of horror all at once. This parasitic entity had grown inside Rohan since his birth, a twin sibling that had never seen the light of day. Its form was disturbingly human, equipped with hair, legs, nails, a skeletal structure, and even a jaw armed with teeth. To an untrained eye, it might even have seemed as though Rohan had miraculously given birth.

Initial speculations of his assistants leaned towards the possibility of a peculiar case of vanishing twin syndrome. This phenomenon involves one twin absorbing the other during the early stages of pregnancy, sometimes leading to the surviving twin bearing two sets of DNA. However, such cases rarely resulted in the absorbed twin continuing to grow within the surviving sibling years later.

As the medical team delved deeper into this medical enigma, they concluded that Rohan’s case was an instance of a supremely rare condition known as Fetus-in-fetu. This condition is characterized by the presence of one twin inside the body of the other. Historically, it was a rarity of such magnitude that there had only been one documented case in the late 19th century, where a mother believed she had prematurely given birth to her child, only to discover it was her undeveloped twin. The realization that they were witnessing this extraordinary medical condition firsthand was as astounding as it was unsettling.