Hello and welcome to HCM, A lump or swelling in the buttock region needs to be investigated. The swelling is most probably a soft tissue swelling since soft tissue swellings are common in this region. certain investigations are required to know the nature of the lesion. An aspiration cytology of the swelling needs to be done to know the exact nature of the swelling. In aspiration cytology, a needle is inserted into the swelling, cells are aspirated, spread on a slide and stained with appropriate stains. The stained cells are studied microscopically to know the nature and character of the lesion. Thus, consult your primary healthcare provider for clinical assessment, investigations and thus management. Thanks and take care Dr Shailja P Wahal