Periscapular mass in a refugee patient: a case of musculoskeletal extrapulmonary tuberculosis

Abstract

This report discusses the case of a male refugee from East Africa who presented with persistent right shoulder pain and was found to have a periscapular mass, whose diagnostic and therapeutic delay was due not only to fragmentation of care, but also a lack of awareness of musculoskeletal manifestations of extrapulmonary tuberculosis. This case underscores the importance of including tuberculosis in the differential diagnosis for a variety of symptoms in patients with risk factors, even if they report previous negative screening.

Background

Tuberculosis (TB) is one of the top causes of death worldwide¹ with an estimated quarter of the human population infected with the causal pathogen, Mycobacterium tuberculosis (MTB).² The global incidence of active TB infection in 2018 was approximately 10 million; most cases are pulmonary, although extrapulmonary TB (EPTB) represented 15% of active cases in 2019.² The majority of people infected with MTB never go on to develop illness from the infection, also called active TB disease. Global public health efforts to reduce the morbimortality of TB primarily focus on the treatment of latent and active TB to prevent further spread. Social determinants such as access to safe housing, good nutrition and living wages must be addressed as well.² Although TB is a global epidemic, 87% of cases are concentrated in 30 countries. In the country of origin of our patient, the incidence of active TB disease is approximately 1.5 per thousand people,² underscoring the importance of routine screening for immigrants and refugees from endemic areas.

Case presentation

The patient is a man in his 60s who had resettled as a refugee from East Africa to the USA in 2011, reporting negative TB testing (unknown type) per Centers for Disease Control and Prevention guidelines at that time. He was seen to establish care at our community health centre primary care. One month prior to this visit, he had been seen at an outside emergency department and another community health centre with the same chief concern of right shoulder pain. He was prescribed a trial of physical therapy which he completed without improvement. His medical history was notable for a hospital admission 7 months prior for pneumonia, treated with levofloxacin, which was followed by readmission for pericardial effusion and new atrial fibrillation, when he received colchicine, vancomycin and piperacillin-tazobactam. At his initial visit in our clinic, the patient reported a chronic cough, pain in his right shoulder associated with a 2 months enlarging mass on his upper back, anorexia, unintentional weight loss of 3 kg over 13 months and nighttime chills. On physical examination, there was a tender to palpation, non-fluctuant 10 cm mass overlying his right scapula. Prior outside evaluation included a normal shoulder radiograph. At this visit, an ultrasound of the mass was ordered, followed by an MRI 1 month later (see interpretation below). He was referred to orthopaedic and general surgery, both of whom declined his referral. Three months after his initial visit, the patient returned to the emergency department with worsening pain and a further 4 kg weight loss, where general surgery drained the collection, yielding 300 mL of purulent fluid and packed the wound. He was treated empirically with doxycycline for 7 days for a bacterial abscess, but in weekly primary care follow-up visits, a copious purulent drainage was seen, without decreasing cavity size or improvement in pain (figure 1).

Figure 1.

Photograph of the patient’s upper back at follow-up after initial incision and drainage shows persistent right periscapular mass.

Investigations

A soft-tissue ultrasound showed a lobular cystic mass 10.0×3.4×12.7 cm of an indeterminate nature. Subsequent MRI demonstrated a 10×10×10 cm fluid collection wrapped around and along the medial scapular border, with lateral extension superficially and deep anterior extension along the chest wall (figure 2). Per the radiologist, the mass was most consistent with an ageing haematoma and not suspicious for malignancy, and osteomyelitis was considered unlikely given the location and appearance.

Figure 2.

Coronal section on a T1-weighted MRI demonstrates the 10×10×10 cm fluid collection that wraps around the medial scapular border, with lateral extension superficially and a deep component that tracks anteriorly between the chest wall and subscapularis muscle. The mass extends from the right lower cervical paraspinal musculature to the level of the scapular tip.

Initial serum studies showed normal cell counts, complete metabolic panel, coagulation studies and haemoglobin A1c, with elevated inflammatory markers—an erythrocyte sedimentation rate (ESR) of 79 mm/hour and a C reactive protein (CRP) of 47.70 mg/L. The drained fluid demonstrated many neutrophils but no organisms on Gram stain, and aerobic cultures were negative. Four weeks after the initial drainage had been performed, bacterial cultures (aerobic, anaerobic and mycobacterial) were repeated, and Gram stain and acid-fast stain revealed no organisms. Cytochemical evaluation and MTB PCR testing were not performed. While these cultures were pending, a limited rheumatologic workup demonstrated a positive anti-nuclear antibody (speckled pattern, 1:160 titre), negative rheumatoid factor and normal cyclic citrullinated peptide antibody IgG. Repeat ESR and CRP were 29 mm/hour and 31.7 mg/L, respectively. Approximately 1 month after repeat cultures were collected, a colony of acid-fast bacilli in mycobacterial cultures was identified and confirmed as pan-susceptible MTB.

Differential diagnosis

The aetiology of the soft-tissue fluid collection identified on imaging was initially unclear. The patient denied any history of trauma that could have led to the development of a haematoma. Periscapular bursitis with associated fluid collection due to mechanical injury or underlying inflammatory or autoimmune condition was considered, though the collection location would have been atypical.³ A malignant effusion was a rare alternate possibility. Given the lack of acute infectious symptoms, overlying erythema, skin breakdown in the affected area and the chronicity, a bacterial abscess was considered unlikely initially, but became the leading diagnosis after purulent fluid drainage, and TB was not considered until several months of symptoms.

Treatment

On notification of positive culture for MTB, an infectious disease specialist was consulted and the patient was admitted to the hospital for expedited evaluation and treatment of EPTB. The studies included radiographs of the spine, chest and shoulder to exclude bony findings consistent with Pott’s disease; a transthoracic echocardiogram to rule out TB pericarditis; serial sputum samples and chest X-ray to eliminate pulmonary TB (PTB) and HIV testing, all of which were negative. Orthopaedic surgery was consulted and declined to perform surgical wash out of the joint. On discharge, he immediately began directly observed therapy with ethambutol, rifampin, pyrazinamide and isoniazid. Because the MTB cultured from his abscess was pan-susceptible, his ethambutol and pyrazinamide were discontinued after 6 and 8 weeks, respectively, and he continued treatment for a total of 9 months.

Outcome and follow-up

Weight stabilisation was seen shortly after starting the antituberculous treatment, and the abscess pocket in the patient’s shoulder began to gradually close. Four months following diagnosis of TB, the patient was evaluated for ongoing right shoulder pain, so he was offered symptomatic treatment with naproxen and Epsom salt soaks and referred to physical therapy, with resolution of symptoms.

Discussion

This patient’s case demonstrates a rare presentation of EPTB, which represents one-fifth of TB diagnoses in the USA,⁴ muscular and soft-tissue manifestations being among the least common subcategories of EPTB. Though the patient was born in a country with high TB prevalence, his clinical presentation did not fit a classic description of TB infection in an immunocompetent person. The unusual characteristics of the periscapular fluid collection without overlying skin changes, and lack of initial response to drainage and antibiotic therapy pointed to an atypical bacterial infection. The broad differential diagnosis for this unusual presentation warranted expanded testing that ultimately revealed a positive MTB culture, and the patient completely recovered with antituberculous medication.

Though it is not fully known what causes some patients to develop EPTB versus PTB, studies that have compared these manifestations suggest that individuals who develop EPTB may have a relative defect in innate immunity.^{5 6} The pathogenesis of muscular manifestations of TB in particular is not well understood, though multiple mechanisms have been proposed: direct traumatic inoculation, haematogenous spread from an undetected primary source or local spread from bony infection.⁷ Similar cases in the published literature are rare, though Elshafie et al⁸ describe a patient with a tuberculous skeletal muscle abscess arising from the erector spinae and Elshafie et al⁸ detail additional cases of primary muscular TB without abscess formation.

Though this patient had a good outcome, delay in detection and treatment of active TB disease can have dire consequences for the individual and the community. Diagnosis requires a high index of suspicion and awareness of the risk factors associated with TB, as well as those that specifically have a higher association with EPTB: female sex, foreign place of birth and positive HIV status.⁴ If EPTB is suspected, the Infectious Diseases Society of America recommends testing serum/aspirate samples for cell count, chemistries, Acid Fast Bacillus smear microscopy, mycobacterial culture and nucleic acid amplification.⁹ In the case of muscular TB, pathological biopsy is considered the gold standard for diagnosis.¹⁰ On diagnosis of EPTB, it is important to evaluate for additional sites of infection, as there can be serious consequences depending on the organ system involved.¹¹ Though not applicable to our patient, musculoskeletal manifestations, particularly adjacent to the thoracic spine, raise the level of concern for Pott’s disease and the possibility of spinal cord compression. Pleural and pericardial EPTB can pose the risk of life-threatening effusions. Furthermore, though there is a very low but documented risk of transmission with muscular TB,¹² EPTB is frequently associated with highly transmissible PTB, and there is a public health responsibility to identify concurrent PTB to ensure appropriate treatment and screening of close contacts.

Despite this patient’s initial negative TB screening, he ultimately developed active TB disease. It is unclear whether he had a false negative initial test result or a new exposure after screening. His reported negative screening result allowed for exposure to fluoroquinolone monotherapy, a TB-active medication reserved for resistant cases, during his prior treatment for pneumonia. This case is emblematic of the disparity in trends in US TB cases, which show a steady decrease in prevalence among US-born individuals with a plateau in prevalence among non-US-born individuals.¹³ There is a need for targeted interventions to further reduce TB cases in this high-risk population.

Though muscular EPTB is a very rare diagnosis, it is important that clinicians include it as part of the differential for high-risk patients. Timely detection and treatment will minimise the risk of complications for the patient and potentially decrease the public health impact.

Patient’s perspective.

The pain and the swelling started around (two months prior to being seen at the clinic). I went (to a local clinic) to see my primary doctor. She examined it and told me to go to the physiotherapy with my own expense which I was unable to cover. I had no chance to do anything except to stay with the pain. After some time, the swelling and the pain increased and started disturbing my sleep and my appetite. I went to the emergency department (of a local hospital). They examined and referred me to physiotherapy. I took the physiotherapy for some weeks and didn't make any difference.

Finally, I searched for information to get another health provider that can help me. I found the information about the (different health system) provider and called the information centre. I was scheduled to see a doctor. By the time I saw the doctor I was almost sick for more than 4 months. The pain and the swelling was increased. I had pain all over my body, chill and burning of the whole body especially during the night and I was unable to sleep. All this time I lost my appetite and lost about 40 lb of weight.

I visited the (clinic of this health system) examined by (one of their doctors).

She referred me to be seen by ultrasound. I took the ultrasound and I was told that the swelling had a (fluid) in it and again referred to be seen by MRI. This was more than a month long scheduled time between these processes. I was suffering during all this time. After the MRI result I was referred to surgery department and my referral was not accepted by the surgery department. Finally I lost hope and went to the emergency department of the (system hospital). I was admitted in and given an outpatient surgery on the same day and removed about 400 cc of fluid from my shoulder blade. They told me to bring one family member the next day to train how to drain the fluid, change the dressing and pack the wound. They gave me all supplies needed for changing and packing.

I suffered for 2 months doing this process. Even though the pain on my body stopped I had the pain of the wound on my shoulder blade and was sleeping on one side of my body that reduced the comfort of my body. After 2 months I was called and admitted to the hospital to be diagnosed for TB. The diagnosis was made with the result of skin TB and I was referred to TB clinic the next day. I was given the necessary medicine and instruction on how to take the medicine. After I started taking this medicine the fluid that drains from the surgery started to reduce from day to day and finally stopped.

After suffering for almost 9 months my wound healed, all my pain stopped and I started to eat food properly, and sleep properly. Even though I still take the medicine I am in good health and my weight also returned to normal. I am very grateful to all those who help me to get my health back.

Learning points.

• Tuberculosis, including latent infection and active disease, affects approximately a quarter of the world’s population and is concentrated in high-risk countries. Patients from these countries should be routinely screened on arrival and again after any high risk exposures, such as travel abroad.

• Extrapulmonary tuberculosis is a rare but serious presentation of Mycobacterium tuberculosis infection that may present nearly anywhere in the body, including musculoskeletal manifestations.

• Tuberculosis should be considered in the differential diagnoses for atypical or ‘cold’ abscesses with purulent drainage but lack of acute infectious signs and symptoms.

Ethics statements

Patient consent for publication

Consent obtained directly from patient(s).