The inclusion criteria were strict in this study. The 8 TB-HLH patients were admitted to the hospital with FUO and with clear evidence of TB. Cases with other secondary HLH were excluded. All of these patients received ATT, and 6 of them received specific treatment for HLH. However, the mortality rate was significantly higher than that for other TB-HLH cases reported domestically and abroad. The reason might be related to their FUO background. In our country, patients diagnosed with TB usually go to specialized TB hospitals for treatment. Our hospital is a center for diagnosis and treatment of rare and tough diseases nationwide. These patients were hospitalized with FUO, representing patients who received more than 3 weeks of treatment before admission with unclear diagnosis, suggesting that this group of patients had atypical clinical manifestations, symptoms, and severe organ damage.