Special pathogen infections presenting with neck mass as the initial manifestation

The etiology of neck masses is complex. Infections caused by Talaromyces marneffei (TM) and nontuberculous mycobacteria (NTM) are uncommon but often present with insidious clinical manifestations, leading to frequent misdiagnosis.

We collected and analyzed data from 13 patients with TM/NTM infections presenting with neck masses at The First Affiliated Hospital of Guangxi Medical University and The Second Affiliated Hospital of Guangxi Medical University. Clinical manifestations, laboratory findings, infection sites, pathogen types, treatments, and outcomes were described and analyzed.

Of the 13 patients, six were male and seven female, with a median age of 57 years (range, 27-73 years). All patients were residents of Guangxi and tested positive for anti-interferon-γ autoantibodies (AIGAs), with titers of 1:2500 in 12 patients and 1:500 in one. The median time from symptom onset to diagnosis was 5 months (range, 1-19 months). Common clinical features included lymphadenopathy (13/13), fever (11/13), respiratory symptoms (10/13), and rash or skin ulceration (8/13). Frequent laboratory abnormalities included leukocytosis (11/13), neutrophilia (11/13), elevated erythrocyte sedimentation rate (12/13), and elevated C-reactive protein (13/13). Coinfection with two or more pathogens was observed in 12 patients. The lungs and lymph nodes were involved in all 13 patients, followed by bone (11/13), skin or soft tissue (8/13), bloodstream or bone marrow (3/13), and nasopharynx (3/13). Neck mass specimens yielded NTM in nine cases and TM in four. NTM was most frequently identified by metagenomic next-generation sequencing (mNGS), whereas TM was detected by culture. The median follow-up duration was 28 months (range, 1-86 months). During follow-up, 6 patients (46.2%) experienced disease exacerbations. Among the 13 patients, 12 achieved clinical improvement after pathogen-directed antimicrobial therapy, while one patient died.

Neck masses have diverse etiologies. TM and NTM infections presenting initially as neck masses are rare and easily misdiagnosed as tuberculosis, malignancy, or lymphoma. Culture and mNGS are crucial diagnostic tools for TM and NTM, respectively. Clinicians should maintain a high index of suspicion for these infections, particularly in immunocompromised patients in endemic regions.