Dissemination of cholangiocarcinoma as pulmonary tumour embolism

A 65-year-old man with stable non-small cell lung cancer presented a hepatic mass during the follow-up. The biopsy revealed cholangiocarcinoma. In the following controls, the patient presented filling defects in pulmonary artery branches and pulmonary thromboembolism was diagnosed, the patient being asymptomatic. The patient received chemotherapy and anticoagulation. In subsequent controls, the lesions in the pulmonary arteries increased and changed morphology.

The first CT scan revealed filling hypodense defects in arterial branches of the middle lobe (ML) and left upper lobe (LUL), especially in lingula, that were compatible with bilateral pulmonary thromboembolism (Figures 2a and 2b).

In the LUL, some new hypodense nodules that were not visible in the previous scans appeared, the largest measuring 8 mm, and several of them were very close to each other. Two other nodules appeared in the left lower lobe (LLL).

In addition, a lesion localized in the left hepatic lobe with peripheral enhancement and a hypodense central area was revealed, with other smaller lesions suggestive of metastasis (Figure 1a). A filling defect of the portal vein and intrahepatic vena cava was seen, which was compatible with thrombosis (Figures 1b and 1c).

The following CT scan done 5 months later revealed an increase in the size of the nodular lesions with a beaded appearance, where hypodense images suggestive of thrombosis were previously described, and which, given the current context, suggested intravascular tumour progression of cholangiocarcinoma (Figures 2c and 2d).

Furthermore, a significant increase in the size of the multiple bilateral nodules was seen, predominantly in the left lung, and new ones appeared, the largest forming a 30 mm conglomerate in the LUL.

Tumour pulmonary embolism (TPE) represents a diagnostic challenge in oncology patients. The reason for this is that both radiological findings and clinical features often resemble those of pulmonary embolism (PE) and the vast majority of PE in this context are of thrombotic origin [1,2]. This is why TPE must be taken into account in the differential diagnosis when subacute dyspnoea appears in oncology patients [3]. It is observed in just a few autopsies [3,4], especially in solid tumours that infiltrate systemic veins such as hepatocellular carcinoma, kidney, breast, chondrosarcoma or lung [2,4,5]. TPE can be macroscopic or microscopic [1,2]. Macroscopic TPE, as the case we presented, can affect the main, lobar or segmentary pulmonary arteries [1], and can produce an acute pulmonary hypertension syndrome due to occlusion of proximal branches [6].

Clinical features are similar to PE of thrombotic origin and include pleuritic chest pain, cough, haemoptysis, and weight loss. It rarely presents with severe shock due to acute massive tumour embolism. Physical examination reveals tachypnoea, tachycardia, fever, signs of right heart failure, cyanosis, and auscultation of superimposed respiratory sounds is unusual [7].

The radiological findings of TPE are dilatation, beaded, lobulated and heterogeneous appearance of the pulmonary arteries, tumour enhancement in the arterial filling defect, transmural extension, the presence in the thrombus of some specific component of the tumour and the lack of resolution after anticoagulant treatment [2,3,5]. Lymphadenopathy and lymphangitic carcinomatosis may also suggest the diagnosis of TPE [6].

PET/CT can be useful for differentiating from thromboembolism [2]. In any case, the final diagnosis will be made by biopsy – being something exceptional – which is indicated in cases with therapeutic options [6].

Given the infrequent presentation of tumour embolism in oncological patients and subtle but characteristic radiological findings, the description of this case is considered essential to make an adequate approach to the differential diagnosis of pulmonary thromboembolism with a lack of response to anticoagulant treatment in these patients.

All patient data have been completely anonymised throughout the entire manuscript and related files.