Introduction <p>This article presents a case study of invasive pulmonary aspergillosis (IPA) characterized by atypical symptoms, specifically pain in the left upper limb. It delineates the clinical manifestations exhibited by the patient, the diagnostic procedures undertaken, and the therapeutic interventions experienced.</p> Case presentation <p>A 75-year-old male patient has been afflicted with spontaneous discomfort in the scapular region, medial aspect of the upper arm, and ulnar aspect of the forearm since March 2023. The initial diagnosis was myofascial pain syndrome with neuropathic involvement. Therapeutic interventions encompassed scapular shock wave therapy, administration of oral pregabalin, and a regimen of acetaminophen-tramadol; however, these measures failed to mitigate the pain. Subsequently, the patient underwent multiple visits to various hospitals. Ultimately, a lung biopsy confirmed the presence of aspergillosis infection, co-occurring with a gram-negative bacilli infection. The patient was administered intravenous voriconazole and piperacillin-tazobactam sodium for anti-infective therapy; however, due to the emergence of severe hallucinations, voriconazole was discontinued and substituted with micafungin sodium.</p> Result <p>The patient’s pain gradually subsided. After symptoms improved, the patient was discharged from the hospital but refused further treatment and ultimately died.</p> Summary <p>The diagnostic intricacies of IPA are characterized by the heterogeneity of its clinical presentations and the absence of distinctive clinical markers. Patients may repeatedly seek medical intervention due to the non-specific nature of their symptoms, resulting in a protracted diagnostic process. A comprehensive multidisciplinary evaluation is imperative in complex pain scenarios to devise optimal diagnostic and therapeutic strategies, thereby enhancing diagnostic precision and augmenting the probability of patient recuperation.</p>