Inconclusive could mean that there were not enough cells to test, based on the biopsy sample, or something could have gone wrong during the shipping and handling of the tissue, which hindered the pathologist ability to analyze the cells.
I would recommend asking your physician specifically about the findings:
"¢ Was there enough tissue taken during the procedure to be examined?
"¢ Was there a problem with processing the tissue sample?
"¢ What would his/her recommendation be to support a final diagnosis?