​Differential diagnosis of ACTH production are : 
-lung carcinoid 
-gut carcinoid 
-thymus carcinoid 
-pancreas carcinoid 
-ovarian carcinoid 
-pancreatic islet cell carcinoma 
-small cell carcinoma of the lung 
-pheochromocytoma 
-medullary thyroid carcinoma 

​Differential diagnosis of central Cushing are : 
-hypothalamic hyperfunction 
-pituitary ACTH secreting adenoma / microadenoma 

​Differential diagnosis of ACTH dependent Cushing are :
-central Cushing
-ectopic corticotropin releasing hormone secreting tumour
-ectopic ACTH production 

​Differential diagnosis of ACTH independent Cushing are : 
-long term glucocorticoid therapy 
-alcoholism 
-depression 
-Adrenal adenoma 
-adrenal carcinoma 
-adrenal hyperplasia 
-severe acute illness
-severe chronic illness
​

​Differential diagnosis of struvite crystal is: 
-urinary tract infection

​Differential diagnosis of leucine and tyrosine crystals is 
-severe liver disease

​Differential diagnosis of cystine crystals is : 
-cystinuria 

​Differential diagnosis of cholesterol crystals is : 
-chylous urine 

​Differential diagnosis of calcium oxalate are : 
-oxalosis 
-food containing oxalate

​Differential diagnosis of drugs causing uric acid crystal and urates are : 
-pyrazinamide 
-chemotherapeutics