Case 125

1. Prepared by Dr. Olanrewaju Oni, visiting Howard University pathology resident and reviewed by Dr. Karen Carroll and Dr. Nikki Parrish.

A patient presented to the emergency department with headache, lip twitching, jaw pain, eye pain and drainage from a surgical site following microvascular decompression and craniotomy surgeries, done 9 weeks and 9 days prior to presentation, respectively. The patient had been on continuous follow up for intermittent post-surgical wound drainage despite being placed on topical and oral antibiotics.

The patient at admission was afebrile, with normal vital signs. The drainage was non-purulent and the incision site was hyperemic. Laboratory investigations revealed normal findings. Follow-up CT head revealed decreasing fluid collection compared to previous CT scans. Wound discharge was sent for culture and patient was discharged on amoxicillin clavulanate.
The direct Gram stain of the wound drainage revealed no polymorphonuclear leukocytes or organisms; the aerobic culture grew Mycobacterium abscessus. Antimicrobial susceptibility testing demonstrated susceptibility to amikacin and imipenem. The patient was placed on imipenem/cilastatin, and relebactam and tigecycline. Subsequent trigeminal neuralgia surgery was scheduled. On follow up, the patient reported significant improvement in his symptoms.

Which one of the following features best describes Mycobacterium abscessus?