Fish Tank Granuloma Presenting as a Nasal Cavity Mass

Mycobacterium marinumis a free-living nontuberculous mycobacterium that is widely distributed in freshwater and seawateraroundtheworld.GranulomatousskininfectionfromM. marinuminpeoplewhoareexposedtofishoraquaticenvironmentsisarare condition known as fish tank granuloma. 0e granuloma mainly occurs on the skin of the upper limb, in a few cases on theface,andrarelyinthenasalcavity.WedescribeacaseofM. marinuminfectionthatpresentedasanasalcavitymass.A57-year-oldwoman who was receiving infliximab for psoriatic arthritis visited our hospital with a complaint of right nasal obstruction. Agranulomatous mass with an irregular surface was found in the anterior part of the right nasal cavity. Tissue biopsy revealedgranulationtissue.Sincetheapplicationofsteroidointmentdidnotreducethesizeofthemass,thetumorwasresectedunderlocalanesthesia, and the base was cauterized. 0e pathological finding was an inflammatory granuloma with negative Ziehl–Neelsenstaining. 0e granuloma recurred 3 months after resection. 0e interferon-gamma release assay (IGRA) test was positive, andtherefore,amycobacterialtissueculturetestwasperformedbecauseofsuspectednasaltuberculosis,whichidentifiedM. marinum.0e nasal cavity mass disappeared 2 months after the administration of minocycline, followed by clarithromycin, and subsequentdiscontinuationofinfliximab.M. marinuminfectioncancause anintranasalmass. IGRAandthe mycobacterialtissueculture testare useful for diagnosis. As in this case, the nasal lesion may be excised as an inflammatory nasal granuloma, and therefore, theremay be many more “hidden” cases ofM. marinuminfection. If nasal granulation is present, the possibility ofM. marinuminfection should be considered.