Chronic upper back and rib pain in a healthy man: re-examining the cause

Back and rib pain is a common presentation that prompts patients to seek medical help. The differential diagnoses (Table 1) range from non-specific musculoskeletal pain occurring in most patients, to life-threatening pathologies in fewer patients.¹ Although it is uncommon for patients to present with life-threatening pathologies, it is essential for clinicians to identify patients presenting with ‘red flags’.^2–4 This case report describes the care of a patient who was initially treated for non-specific musculoskeletal pain, but his pain persisted for 10 weeks and was eventually attributed to a life-threatening pathology.

Table 1.  Differential diagnoses of upper back and rib pain and their clinical manifestations^2–4

A previously healthy 44-year-old Indian male presented to a Sydney General Practitioner (GP) in late 2017 with a 2-week history of a sudden onset, localised, sharp, constant lower right rib and left upper back pain. He also visited his regular GP at that time from his workplace in Bowral. The pain was worse at night and on movement and was not relieved by analgesia. He denied any preceding trauma to the area. There were no complaints of bladder and bowel dysfunction, paraesthesia, and weakness. He did not experience rash, fever, night sweats and weight loss. The patient denied any past medical and family history of cancers. In his initial history, there was no known recent travel. The patient was born in India and migrated to Sydney in 2009.

His vitals and gait were normal. There was no erythema, swelling and overlying skin changes on his chest. Localised tenderness was elicited on the right posterior 11^th rib and left paraspinal muscles in the T4 region. Full range of motion was elicited in the cervical, thoracic, and lumbar spine. Heart sounds were dual and lung sounds were clear. His Bowral GP did an ECG a day earlier, which revealed normal sinus rhythm and ordered a chest X-ray and soft tissue ultrasound of his ribs and back, which were normal. As the initial impression was a non-specific musculoskeletal pain, the patient was treated conservatively.

The patient re-presented to his Bowral GP 1 month later with ongoing pain unrelieved by analgesia. A CT chest scan ordered by his Bowral GP revealed no abnormalities. He later re-presented to his Sydney GP a month later for his persistent pain. As his pain had been ongoing for 10 weeks, he was referred to a rehabilitation specialist for further assessment. Uncertain of the diagnosis, the specialist sent the patient for a bone scan.

The patient’s bone scan (Figure 1) revealed an osteolytic process in the right 11^th rib. As the initial CT scan had insufficient views visualising the patient’s ribs, a repeat CT chest, abdomen and pelvis scan (Figure 2) was performed; this demonstrated lytic lesions in T2 vertebral body and right posterolateral 11^th rib, with no primary identified and prompted an urgent referral to an oncologist. The patient’s serological results for cancers were unremarkable. As the diagnosis was unclear, he was referred to a second oncologist. On detailed questioning by the second oncologist, the patient stated that 2 months before his presentation, he was in India, his home country, for a month. India is tuberculosis (TB)-endemic. Knowledge about his recent visit to India reminded the specialist of the risks of TB associated with the patient’s background. A provisional diagnosis of skeletal TB was made and the patient underwent a bone biopsy of his lytic lesions.

Figure 1.  Whole body bone scan revealed an osteolytic process in the right 11^th rib (red arrow).

Figure 2.  A computed tomography (CT) chest, abdomen and pelvis, coronal (left) and sagittal (right) plane, completed 1 week after a bone scan (Figure 1), revealed an osteolytic process in the right 11^th rib (CT coronal plane) and T2 vertebrae (CT sagittal plane).

Results of his bone biopsy revealed Mycobacterium tuberculosis. The patient completed 9 months of anti-TB treatment and his pain improved significantly.

Revisiting the initial diagnosis of non-specific musculoskeletal pain is essential when patients’ pain fails to improve. Clinicians should derive clues from the patient’s history to identify alternative pathologies causing pain. Despite being reviewed by two GPs and three specialists over a period of 2 months, only the last specialist made the association between the patient’s background and his risk of acquiring skeletal TB.

Most cases of extrapulmonary TB seen in Australia are from countries and regions outside Sydney.^5,6 As Sydney is not an endemic region for TB, there was initially a low suspicion for skeletal TB with respect to the patient’s presentation, which accounted for the delayed diagnosis. However, this patient’s persistent pain should have prompted exploration of more obscure pathologies in relation to his background. As the patient was from India, skeletal TB should have been prioritised as a likely differential diagnosis.

Magnetic resonance imaging (MRI) is the best modality for characterisation of soft tissue extent of infection, including encroachment of adjacent organs and spinal cord. MRI is superior to imaging with CT.

Nuclear medicine bone scan is the most sensitive test for determining extent of active skeletal disease, as the entire skeleton is imaged; however, specificity is low, so areas of abnormal uptake on a bone scan need to be further assessed with other imaging modalities.

Computed tomography (CT) is the best modality for detecting and characterising infective bone lysis. CT can characterise extension of infection into the soft tissues including TB-associated calcification.

X-ray of the spine and ribs can demonstrate bone lysis from infection. Chest X-rays are good for looking for features of previous TB infection, but do not predict skeletal involvement.

The diagnosis of skeletal TB is challenging because there is no evidence of active chest disease in most patients, as in this case where a clear chest X-ray was reported. Other imaging modalities can be used to assist in the diagnosis of skeletal TB (Table 2).^7,8 Suspicion of skeletal TB is usually derived from history focusing on the patient’s TB contacts.⁹ By focusing on the patient’s frequency of visiting India, skeletal TB would have been suspected much earlier.

Table 2.  Different imaging modalities to assist in the diagnosis of skeletal TB^7,8

The authors declare no competing interests.

This case report did not receive any specific funding.