Bone Metastasis As the Initial Presentation of a Hidden Bronchogenic Carcinoma

Abstract

Primary malignant bone tumours are on the whole rare, while secondary bone tumours are much more common. Up to 40% of bone metastases are associated with lung cancer. This case report highlights a rare presentation of metastatic bone disease as the initial presentation of a primary lung malignancy and only very few cases were mentioned in literature with the same presentation of no clinical signs of the primary lung pathology, except for an unexpected radiological finding of a suspicious lung lesion. An 85-year-old gentleman presented with a progressive lower backache radiating to both lower limbs over a period of 4 weeks associated with difficulty in walking, significant weight loss, and decreased appetite. A skeletal survey showed only spondylolisthesis. However, no clinical improvement was noticed with conventional therapy. Examination of the respiratory, gastrointestinal, and genitourinary systems was normal. Ultrasonography of the abdomen and pelvis, and the findings of the colonoscopy did not add anything. During the third week of follow-up, the patient reported unbearable severe pain in the left arm. A plain radiograph revealed a pathological fracture of the humerus. Secondary bone metastasis was suspected. Although the patient was a non-smoker and there were no clinical signs of underlying lung disease, a simple plain chest radiograph, unexpectedly, showed a suspicious right lower lobe lesion. Therefore, a contrast-enhanced computerized tomography (CT) scan for the chest, abdomen, and pelvis was done which revealed a right lower lobe lesion of bronchogenic carcinoma with distant metastasis. Unfortunately, the patient died after 3 weeks of palliative therapy when he was admitted to the hospital with acute renal failure and septic shock. Bone metastases in lung cancer predict a poor prognosis and short-term survival. The diagnosis of such a challenging presentation requires a high index of suspicion. If the patient had been sent for a plain chest radiograph at first, lots of time and effort could be saved in reaching the diagnosis without the need for further sophisticated or invasive diagnostic procedures.

Keywords: advanced malignant tumour; bone metastasis; bronchogenic carcinoma; chest x ray; diagnostic approach; lung carcinoma; oncology; palliative therapy; pathological fracture.

Figure 1. Plain lumbo-sacral radiograph showing L4-5 spondylolithesis and signs of osteoarthropathy.

Figure 2. (A) and (B) images showing different MRI parasagittal sections of the spine with myelography representing abnormal signal intensity with anterior wedge compression in D11 and D12.

Figure 3. Plain radiograph showing pathological fracture in the left humeral shaft.

Figure 4. Plain chest radiograph showing right lower lobe lung lesion.

Figure 5. Contrast enhanced CT scan of the chest showing right lower lobe partly spiculated partly lobulated lung lesion in coronal section (A) & transverse section (B).