Spot the diagnosis161-165

(161) An emaciated patient of twenty comes with a depressed scar in the neck . Spot the diagnosis?
(162) A kashmiri patient of sixty comes with a chronic ulcer all around the umbilicus .
(163) A boy of fifteen has come with a swelling in the metaphysis of tibia with  variable consistency . Spot the diagnosis?
(164) A patient has come with the swelling in the metaphysis of tibia . His x-ray shows a cavity in the bone and the cavity is surrounded by a thick , sclerosed bone . There is one sequestrum inside the cavity . Spot the diagnosis?
(165) A patient consulted a surgeon for a swelling in the diphysis of tibia . The doctor says that his x-ray picture is most diagnostic and the tumor is highly radio-sensitive . This tumor melts like snow  in sunshine . Spot the diagnosis?
Answers.
(161) Tuberculosis .
(162) Carcinoma skin (khangri cancer) .
(163) Osteogenic sarcoma .
(164) Brodies abscess .
(165) Ewing's tumor.