<unk>  is relatively nonspecific in clinical presentation. Therefore, more common skin conditions, like cellulitis, foreign body reaction, skin cancer, and fungal or parasitic infections, are often explored first. Overall, diagnosis and treatment of this rare skin infection is often delayed because of a lack of suspicion. Lab tests for finding M. marinum include cultures where a swab or sample is taken and grown in the laboratory. Cultures of M. marinum are fairly difficult to grow, and results may take several weeks. The culture may be negative, even if there is an active infection. Treatment may still be considered even if the test results are negative, especially if the patient's history supports past fish or fish-tank exposure. In the absence of positive culture results, a skin or tissue biopsy may be a helpful test to render a microscopic diagnosis. Another technique that can be used to detect the bacteria is Polymerase Chain Reaction (PCR). A biopsy sample itself is sufficient to detect the exact type of bacteria by means of PCR.
Aquarium granuloma
Dentigerous cyst
Papillary hidradenoma
Rhinoscleroma
Tornwaldt cyst
Paradental cyst
Nevus of Ota
Actinic granuloma