Hand-drawn mapping for bronchoscopic navigation and endobronchial ultrasound-guided transbronchial needle aspiration in a pericardial mass invading the main pulmonary artery

Dear Editor,

A 56-year-old female patient, diagnosed with a case of diffuse large B-cell lymphoma (DLBCL), was given six cycles of chemotherapy, resulting in a complete response 2 years ago. A follow-up whole-body positron emission tomography (PET) scan showed the interval appearance of an 18F-fluorodeoxyglucose (FDG) avid nodular soft tissue pericardial mass, which was invading the main pulmonary artery (MPA), also referred to as the pulmonary trunk [Figure 1a and b]. It was conjectured that the lesion could be accessed via the superior subsegment (LB4) bronchus of the lingula using endobronchial ultrasound (EBUS) bronchoscopy, based on an analysis with the Hierarchical clock-scale hand-drawn mapping for bronchoscopic navigation[1] according to computed tomography (CT) images [Figure 2]. The chest CT slice was rotated 180° to match the spatial structure of the CT image with bronchoscopic observation, allowing identification of the LB4 subsegment bronchus superiorly and the LB5 inferiorly [Figure 2a]. Manual navigation using the flipped CT imaging began from the left upper lobar bronchus, depicted as the outermost circle. The subsequent bronchi were marked as smaller circles within the larger circle and labelled numerically. This process continued until the target pericardial mass lesion, which was adjacent to the LB4 subsegment bronchus, was mapped [Figure 2b]. An EBUS by an Olympus BF-UC180F convex-probe (CP-EBUS) bronchoscope was performed through a laryngeal mask airway under general anaesthesia using a combination of midazolam, fentanyl, and propofol. The EBUS scope was introduced in the superior subsegment (LB4) of the lingula. The EBUS visualised a hypoechoic, irregular mass [Figure 1c] invading the MPA. The mass measured 23.4 mm on linear EBUS. To minimise the potential risk of bleeding, the EBUS scope was oriented to localise an area of the mass outside the MPA to perform the EBUS-guided transbronchial needle aspiration (EBUS-TBNA) using a 22 G needle [Figure 1d and Video 1]. Three passes were made under real-time ultrasound guidance. The adequacy of the specimen was confirmed by rapid on-site cytology. The EBUS-TBNA cytology smears were highly cellular and showed sheets of singly scattered intermediate to large-sized atypical lymphoid cells with a high N: C ratio, irregular nuclear membrane, coarse nuclear chromatin, and multiple small nucleoli, suggestive of a high-grade non-Hodgkin lymphoma [Figure 1e]. Immunohistochemical analysis of the cell block confirmed the recurrence of DLBCL.

Figure 1.

PET scan (a and b) showing an 18F-fluorodeoxyglucose (FDG)-avid nodular soft tissue pericardial mass (white arrows), which is invading the MPA. An EBUS image (c) showing a hypoechoic, irregular mass with invasion of MPA. An area of the pericardial mass identified outside the MPA showing EBUS-guided transbronchial needle aspiration (d). The Giemsa stain (×20) of the EBUS-TBNA cytology showing abnormal cell morphology consistent with high-grade non-Hodgkin’s lymphoma (e). MPA = Main pulmonary artery, PET = Positron emission tomography, EBUS = Endobronchial ultrasound, EBUS-TBNA = EBUS-guided transbronchial needle aspiration

Figure 2.

The chest CT slice flipped 180° (a), showing the LB4 subsegmental bronchus superiorly and the LB5 inferiorly. The manual navigation (b) starting from the left upper lobar bronchus (the outermost circle), subsequently, the next generation of bronchi were marked as a smaller circle located within the upper story (larger circle), to map the target pericardial mass abutting the LB4 subsegment bronchus of the lingula. CT = Computed tomography

The diagnosis of pericardial lesions is challenging, often needing invasive surgical biopsy. This case features the use of EBUS-TBNA as a minimally invasive diagnostic modality for pericardial pathology. The role of EBUS-TBNA in the diagnosis of pericardial lesions has rarely been described in a few case reports only. Ashinuma et al. performed EBUS-TBNA to diagnose a case of pericardial mesothelioma.[2] Hossain and Chawla reported a case of pericardial mass diagnosed as angiosarcoma by EBUS-TBNA.[3] One case of an intrapericardial bronchogenic cyst showing a high CA19-9 level in the fluid sampling by EBUS-TBNA was treated by complete surgical resection.[4] An EBUS-guided pericardiocentesis in a case of a loculated pericardial effusion has also been reported.[5] Endoscopic ultrasound with an EBUS bronchoscope introduced in the oesophagus, often referred to as EUS-B, has also been reported for aspiration of pericardial effusion[6] and diagnosing left atrial tumours.[7] Although EUS-B is a safe and effective diagnostic approach, even for patients in poor general condition,[8] there is a possible higher risk of infection. In our case, the pericardial mass was not accessible via the oesophageal route. To the best available literature search, this is probably the first case reported of convex-probe EBUS-guided sampling of a pericardial mass in India. This is also the first case in which hand-drawn mapping for bronchoscopic navigation was used to guide the CP-EBUS scope to an unusual location in the superior segment of the lingula to sample a pericardial lesion in the mediastinum. This case is also unique as the pericardial mass was invading the MPA, which required careful manoeuvring of the CP-EBUS scope to localise an area of the mass that was outside the MPA to prevent any serious complication while performing TBNA. This report highlights that EBUS-TBNA may be considered as a valuable tool for diagnosing pericardial masses, in a few selected cases, where pericardial lesions are adjacent to the airways, offering a less invasive alternative to surgical biopsies. However, the operator must be experienced, and alternative diagnostic methods should be thoroughly evaluated.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.