Scrofula due to Mycobacterium Avium Complex Lymphadenitis

Allexa Hammond, MD and Nilum Rajora, MD

Published March 1, 2020

A 45 year old male with AIDS (CD4 109 cells/microliter, viral load 5573 copies/milliliter, recently started on anti-retroviral therapy) presented with a one month history of an enlarging, non-tender, right-sided neck mass associated with fevers.  He had been treated with doxycycline without improvement. On admission, the patient was febrile (100.4° F) and tachycardic with a ten centimeter, erythematous and fluctuant right-sided neck abscess (Image 1). Cervical, retropharyngeal and supraclavicular lymphadenopathy were confirmed on CT imaging (Image 2).  A lymph node biopsy obtained via fine needle aspiration in addition to two out of three acid fast bacilli sputum cultures were positive for Mycobacterium avium-intracellulare complex (MAC).  The patient was diagnosed with MAC lymphadenitis with pulmonary involvement and started on rifabutin, ethambutol and azithromycin.  The patient was discharged in stable condition. Upon follow-up in clinic, there was a noted decrease in the size of the abscess with ongoing active drainage, indicative of appropriate response to therapy.

Image 1

 
  Image 2

Questions:

Lymphadenitis due to mycobacterial infection usually presents with which of the following symptoms?

1. Painful, rapidly progressing enlargement of the affected lymph node(s) underneath the axilla
2. Painless, gradually progressing enlargement of the affected cervical lymph node(s), usually asymmetric 
3. Painless, rapidly progressing enlargement of the affected cervical lymph node(s)
4. Blistering rash with subsequent development of a painless abscess on the neck

Scrofula can arise due to infection with which organism?

1. Mycobacterium avium complex
2. Mycobacterium tuberculosis
3. Mycobacterium scrofulaceum
4. Any of the above

Answers and explanations:

Question1
Answer 2. 

Found in soil- and water-rich environments, MAC is an opportunistic infection often affecting HIV/AIDS patients1.  Also known as scrofula, mycobacterial lymphadenitis characteristically presents as a painless and violaceous mass with slow growth over a period of several weeks2. The mass typically involves the cervical lymph nodes, eventually becomes fluctuant and may start to openly drain; the patient may also experience low grade fevers. Treatment options typically include medical management using multiple anti-microbial agents, such as rifabutin in combination with ethambutol and a macrolide such as azithromycin or clarithromycin1.

Question 2
Answer 4.

Mycobacterial lymphadenitis, although historically associated with infection due to Mycobacterium tuberculosis, can also be caused by other mycobacteria such as Mycobacterium avium complex (as noted in this case) and Mycobacterium scrofulaceum. Given the relatively non-specific physical examination findings, the provider may be inclined to consider more commonly diagnosed conditions before considering mycobacterial infection, such as lymphoma or pyogenic abscess due to S. aureus or Streptococcus species; however, this may lead to a misdiagnosis and delay in proper treatment2.  Clinicians should take note that mycobacterial infections may imitate many of the clinical features associated with other pathologies. To avoid a misdiagnosis, there should be a very low threshold to evaluate for mycobacterial infection in HIV/AIDs and other immunocompromised patients, particularly in the appropriate clinical context.

References:

1. Corti M, Palmero D, 2008. Mycobacterium avium complex infection in HIV/AIDS patients. Expert Review of Anti-infective Therapy;6(3):351-363.

2. Levin-Epstein AA, Lucente FE, 1982. Scrofula- the dangerous masquerader. Laryngoscope; 92:938-944.

Author Bios:

1. Allexa Hammond, M.D. is an Internal Medicine resident at the University of Texas Southwestern Medical Center in Dallas, Texas. 

2. Nilum Rajora, M.D. is a Nephrologist and General Internist who currently practices at the University of Texas Southwestern Medical Center in Dallas, Texas.