Brief Answer: Either Cushing's or lipoma. Increase in size. ACTH Detailed Answer: Hello, I have gone through the query and understand your concern. First thing you have to know is buffalo hump is some thing different from a simple large lipoma. Lipoma is non-cancerous (benign) growth made up from fat cells that clump together. Buffalo hump is a lump of fat that develops at the top of the back between the shoulders due to the high level of cortisol or glucocorticoid (hormones produced by the adrenal gland) levels in the blood. It is called Cushing syndrome. Usually it is caused by excessive use of corticosteroids. Do you use steroids for any other purpose? As you suspected, it can also be caused by Pitutary or adrenal gland tumour. But it is associated with the symptoms of increased cortisol like easily bruisable skin, excess hair growth, Facial swelling and redness, High blood pressure (hypertension), Menstrual changes, Obesity. If you have these symptoms, then you need further investigation for cortisol excess by measuring the amount of cortisol in blood and urine in your body. Then we have to find the cause of the excess cortisol in your blood. This needs another investigation - level of adrenocorticotropin hormone (ACTH) in your blood. High level indicates tumour in your pituitary gland or, less commonly, in your lungs. Low levels of ACTH would suggest that there is a tumour in one of your adrenal glands. Further MRI scan of the pitutary scan may be needed to identify the tumour. Depending on the cause for cushing syndrome, the treatment varies. Lump at the back of neck and shoulder may be due to simple large lipoma. This can be confirmed by Ultrasound examination and also removed easily by surgery Regardings it increase in size, it may increase in size in both lipoma and cushing syndrome with or without any exercise due to lipomatosis. Waiting for your response.

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