This was investigated with magnetic resonance imaging resulting in an incidental finding of mediastinal mass and pulmonary infiltrates. the patient in compliance with ethical guidelines. Case presentation A 23-year-old Asian female initially offered to rheumatology with over a one-year history of neuropathic pain, alongside abnormal white cell count and inflammatory markers. This was investigated with magnetic resonance imaging resulting in an incidental obtaining of mediastinal mass and pulmonary infiltrates. An initial diagnosis of TB was made despite testing unfavorable for acid-fast bacilli and anti-tubercular treatment was commenced. Four months later, following clinical deterioration and further investigations, a mediastinal biopsy assisted in diagnosing Stage IV HL. Conclusions Lymphoma is usually often misdiagnosed as TB, prolonging time to treatment and may adversely impact Gatifloxacin hydrochloride patient prognosis due to disease progression. Existing TB guidelines for smear-negative cases are not obvious when to consider option diagnoses. In smear-negative TB, lymphoma should be considered as a differential and definitive diagnostic assessments such as molecular screening and histological examination of biopsies should be considered earlier in the diagnostic work-up to prevent diagnostic delay. In this case, as MRI findings did not reveal any neurological abnormalities, it is unlikely this occurred. Open in a separate windows Fig. 5 Timeline of case statement. This timeline summarises the historical information and clinical interventions and management of this case On further review of the MRI, mediastinal and pulmonary pathology were incidentally found and were confirmed by contrast-enhanced CT scan. The top differential based on clinical-radiological diagnosis was TB. TB is one of the leading causes of mortality worldwide, affecting approximately 10 million people globally, with highest incidence in South East Asia and Africa [7]. In the western world, the UK is usually a key hotspot with over 5000 cases per year [8]from multiple samples of bodily fluids or tissue using AFB smear assessments, cultures and/or quick nucleic acid amplification assessments for example GeneXpert? [9, 10]. In this case, blood was tested for TB with ELIspot /T-SPOTblood test, and BAL smears were tested for AFB, which were all unfavorable for TB prior commencing treatment. TB Gatifloxacin hydrochloride culture results received 6?weeks later were also negative. Investigations such as blood assessments and sputum samples are not usually able to identify the presence of TB. Swai [11] exhibited the typical diagnostic work-up for smear-negative TB used in clinical practice experienced poor sensitivity and specificity of 38.1% and 74.5% respectively. Therefore, due to the importance of controlling disease spread, current guidelines from your National Institute of Clinical Superiority (Good) recommend if active TB is usually suspected, anti-tubercular therapy should be started without waiting for culture results and courses should be continued with close monitoring of response despite unfavorable SLC39A6 results if TB is still considered likely [10]In this case there was no history of recurrent cough, chest pain and heat on presentation. Despite Gatifloxacin hydrochloride continuing anti-TB treatment, the patients condition worsened. Repeated TB-focused assessments were negative, and finally the diagnosis of HL was confirmed with an anterior mediastinal biopsy. We inquire at what point should an alternative diagnosis be considered in a work-up for TB and when should we consider performing a biopsythe definitive diagnostic test which can identify both TB and lymphoma? Current Good guidelines for TB do not clearly specify at what stages should option diagnoses be considered, nor do they provide details of important distinguishing factors that could assist in differentiating these conditions [10, 12]. The challenging nature of diagnosing lymphomas has been previously reported. Both TB and lymphoma can have similar non-specific systemic symptoms (fever, excess weight loss and night sweats), as well as lymphadenopathy, and granulomatous inflammation on cytology and histology [13]. The non-specific symptoms can often make it difficult for patients to seek medical help or prompt appropriate referral from main care to diagnose patients in early stages of disease [14]. Raising awareness of important differences between TB and lymphoma could help improve diagnostic accuracy in earlier stages of disease. Features suggesting non-TB pathology include: no known exposure to TB or previous TB infection, involvement of supraclavicular lymph nodes, unfavorable first-line TB investigations [for example tuberculin skin test (TST), sputum samples for AFB smears], and lack of response to anti-tubercular treatment within the first 2?months [13]. However, TST.