Cryodebulking of endobronchial hamartoma via fibreoptic bronchoscopy and literature review

Abstract

Endobronchial hamartoma is a rare tumour. We report a 65-year-old woman with a history of recurrent pneumonia. Bronchoscopy revealed a 1 cm endobronchial mass obstructing the left upper lobe bronchus. Histopathological examination was consistent with a pulmonary hamartoma. This lesion was successfully debulked endoscopically with the use of a flexible cryoprobe without any complications. This case highlights both the importance of investigating recurrent pneumonia and the usefulness of endoscopic recanalisation in an obstructed segmental bronchus.

Background

Endobronchial hamartomas are rare and often asymptomatic. They are often detected incidentally on chest radiographs. The symptoms depend on the location of the tumour. Symptoms manifest due to progressive airflow obstruction leading to recurrent pulmonary infection. We report a patient diagnosed with pulmonary hamartoma as a result of evaluation for recurrent pneumonia. We performed a flexible bronchoscopy with serial cryoprobe debulking of the lesion. The airway remained patent at 3 months and she had no further episodes of pneumonia.

Case presentation

A 65-year-old woman with type 2 diabetes mellitus and hypertension presented with a 1 week history of cough and fever. She was a non-smoker and had a recent admission for community-acquired pneumonia which required treatment with intravenous amoxicillin–clavulanic acid and azithromycin. She had a CURB-65 (confusion, blood urea >7 mmol/L, respiratory rate >30/min, blood pressure <90/60 mm Hg, age >65) score of 3. On clinical examination, the respiratory rate was 30 breaths per minute and oxygen saturation 90% on room air. Respiratory examination revealed reduced breath sounds and coarse crepitations in the left lung. She was initiated on broad-spectrum anti-pseudomonas piperacillin–tazobactam.

Chest radiograph revealed a soft tissue opacity in the left upper zone with abrupt truncation of the left upper lobe bronchus (LUL) and a veil-like opacification obscuring the left heart border (figure 1A). Serial sputum cultures were negative. A contrast-enhanced CT of the thorax showed a calcified intraluminal mass obstructing the LUL bronchus with distal atelectasis (figure 1B). We proceeded with a flexible bronchoscopy which revealed a LUL endobronchial polypoidal mass partially obstructing the lumen (figure 1C, D). Bronchial washing for nucleic acid amplification test for Mycobacterium tuberculosis DNA and resistance to rifampicin (GeneXpert MTB/RIF) and bacterial culture were not detected. Endobronchial biopsy histopathological examination showed hypercellular submucosal cartilaginous nodule with islands of cartilage close to the bronchial epithelium suggestive of endobronchial hamartoma (figure 1E, F).

Figure 1.

(A) chest radiograph showed a soft tissue opacity in the left upper zone with abrupt truncation of the left upper lobe (LUL) and a veil-like opacification obscuring the left heart border. (B) CT thorax (axial view, mediastinal window) showed a calcified intraluminal mass obstructing the LUL bronchus with distal atelectasis. (C) Smooth polypoidal mass (blue arrow) occluding the LUL bronchus. (D) Patent LUL bronchus post cryodebulking. (E) The endobronchial biopsy showed nodular proliferation of mature adipose tissue. (F) The benign hyaline cartilage is hypercellular with an irregular surface.

She showed poor clinical response to antibiotics with unresolving pneumonia and needed persistent ventilatory support. We attempted rigid bronchoscopy but the patient was unable to achieve target ventilation. We proceeded with a flexible bronchoscopy (system: EMS LUCERA; Olympus and bronchoscope: BF-1T260) and debulked the endobronchial hamartoma using a cryoprobe via the endobronchial tube. We introduced a flexible cryoprobe (length 90 cm, diameter 1.9 mm) through the working channel of the flexible bronchoscopy into the tumour. The tip of the cryoprobe was pushed into the hamartoma, and repetitive cycles of 6 s of freezing and thawing was done. Both cryoprobe and flexible bronchoscope were mechanically removed at each cycle with the tumour tissue sample measuring 5–10 mm. We then rapidly thawed the tissue in saline water for 5–10 s. This procedure was repeated until the hamartoma has been fully extracted and the target bronchus recanalised. The oxygenation of the patient improved post removal of the endobronchial hamartoma and the patient was successfully extubated.

Outcome and follow-up

The airway remained patent following bronchoscopic surveillance 3 months after the procedure and she had no further episodes of pneumonia.

Discussion

Pulmonary hamartomas are rare benign lung neoplasm and can involve the parenchymal and endobronchial regions. Endobronchial hamartomas account for only 10% of pulmonary hamartoma.¹ These benign neoplasms consisting of multiple mesenchymal cells line like cartilage, fat, fibrous tissue and entrapped respiratory epithelium.¹ The mean age of presentation is between the sixth and seventh decades with male preponderance.

The exact genetic origin is unknown with cytogenetic analysis showing abnormal karyotype and recombination between chromosomal bands 6p21 and 14q24.² Clinical symptoms often occur when there is a significant bronchial obstruction with postobstructive pneumonia. Haemoptysis can occur if the hamartoma invades or impinges on vascular structures.

Chest radiograph changes are non-specific and generally related to postobstructive changes, such as atelectasis, parenchymatous consolidation and bronchiectasis. The classical findings are soft tissue attenuation, well-circumscribed, smoothly marginated solitary nodule mass with or without calcification (classically popcorn type).³ In our patient, the chest radiograph showed an opacity truncating the LUL bronchus suggestive of bronchial cut-off sign. There was also evidence of left LUL collapse due to the presence of a veil sign. The visible left hemidiaphragm indicates sparing of the left lower lobe. Chest CT typically shows a fatty lesion with a density between −40 hounsfield units (HU) and −120 HU without contrast enhancement alternating with foci of calcification. Bronchoscopy is essential for biopsy to differentiate benign from malignant endobronchial tumour. They appear as broad-based white or grey polypoid nodules either sessile or with a thin pedicle with a firm consistency within the lumen of a large bronchus. A retrospective study of 47 patients with endobronchial hamartomas found equal distribution throughout both lungs with no clear lobar predilection.⁴

Histologically, pulmonary hamartomas comprise of mature cartilage with variable amounts of fibromyxoid connective tissue, fat, bone, smooth muscles and lined by entrapped respiratory epithelium or metaplastic squamous epithelium.

The prognosis of endobronchial hamartoma is generally favourable with a low rate of recurrence following complete resection. There is no consensus regarding the follow-up interval and frequency. Long term follow-up showed no evidence of the malignant transformation of hamartoma in most cases.⁵

The treatment of endobronchial hamartoma has evolved. The earlier treatment options included invasive surgery ranging from bronchotomy, segmentectomy, lobectomy and pneumonectomy. With the advancement of technology, the treatment is now less invasive with the use of endoscopic excision with argon plasma coagulation, electrocautery, neodymium-doped yttrium aluminium garnet laser, coring with a rigid bronchoscope or tumour debulking with a flexible cryoprobe (table 1). The use of rigid bronchoscopy for excision has been performed in selected tumour sites that can be reached such as the trachea and main bronch.⁶

Table 1.

Reported cases of the endobronchial hamartoma

Author/year	Age/sex	Symptoms	Location (bronchus)	Bronchoscopy	HPE	Treatment	Relapse
Minalyan et al 20198	49/M	Haemoptysis, SOB	LUL	White mass	Lipomatous hamartoma	Forceps debulking with cauterisation.	No
Geramizadeh et al 20199	30/M	Cough, haemoptysis	RMB	–	Cartilage, fibroblastic matrix, foci of ossification.	Thoracotomy, pneumolysis, and right pneumonectomy.	No
Pojda et al 201910	74/F	Cough, SOB	RLL	–	Cartilaginous and fatty differentiation with extensive chondroid and chondro-myxoid areas.	Thoracotomy with tumour resection.	No
Amore et al 201811	68/M	Cough, fever	RLL	Smooth round polypoid	Hamartoma	VATS RLL superior segmentectomy.	No
Haridasa et al 201812	28/M	Cough, fever, chest pain	LUL	Smooth polypoidal	Hamartoma	VATS with left upper lobectomy.	No
Ghosh Chatterji et al 201813	53/M	Cough, SOB	LLL	–	Chondroid hamartoma	Left lower lobectomy.	No
Uzer et al 201714	61/M	Incidental	Trachea	Polypoid and vesicular mass	Hamartoma	Rigid bronchoscopy with resection.	No
Ahmed et al 201715	53/M	Cough	LUL	Smooth mass	Hypercellular submucosal cartilaginous nodule with islands of cartilage.	Laser resection of the tumour and balloon dilation. LUL bronchus obstruction after 2 years and required LUL resection.	Yes
Minegishi et al 201516	75/M	–	LLL	–	Chondroid tissue covered with bronchial-type epithelium.	Video-assisted radical left lower lobectomy.	No
Mertoglu et al 201517	48/M	Cough, fever	RMB & RBI	Mobile mass	Hamartoma	Endobronchial argon plasma coagulation and electrocauterisation.	No
Sim et al 201418	49/M	–	RLL	Pedunculated mass	Chondroid hamartoma	Cryotherapy with cryodebridement via flexible bronchoscopy.	No
	53/M	–	LLL (LB6)	Pedunculated mass	Chondroid hamartoma	Cryotherapy with cryodebridement via flexible bronchoscopy.	No
Oguma et al 201419	66/M	Fever	RUL	Polypoidal tumour	Mature cartilage and fat tissue in the deeper layer.	Forceps debulking, RUL lobectomy.	No
Gayathri Devi 201320	65/M	Cough, SOB	RUL	Polypoidal tumour	Fibrocollagenous tissue and mature fat cells.	Conservative. Asymptomatic 2 years post-bronchoscopy.	–
Poonja et al 201321	56/F	Incidental	LLL	LLL bronchus tumour	Hamartoma	Polypectomy snare with electrocautery excision.	No
Schneider et al 201222	69/M	SOB	RIB	Smooth round tumour	Fatty tissues	Rigid bronchoscopy with loop excision and laser therapy.	No
Yildirim et al 201123	57/M	SOB, chest pain	LMB	Pedunculated mass	Grey, lobulated, elastic cartilaginous mucosal tissue.	Electrocautery by flexible bronchoscopy.	No
Mondello et al 201124	65/M	Incidental	LMB	Pedunculated mass	Hamartoma	FibFibreoptic bronchoscopy and electrosurgical snaring.	No
Rai et al 201025	40/M	Cough, fever, anorexia	LMB	Pink pedunculated mass	Disorganised lobules of cartilage and adipose tissue.	Resected endoscopically by diode laser.	No
Lakhotia et al 200826	35/M	Cough, haemoptysis, SOB	LMB	Yellowish tumour	Lipomatous hamartoma	Left pneumonectomy.	No
Kurkcuoglu et al 200527	64/M	Cough, SOB	LMB	Polypoidal tumour	Bronchial glandular tissue, smooth muscle, connective tissue and mature adipose tissue.	Sleeve left upper lobectomy.	No
Mysorekar et al 199628	48/M	Cough, SOB	LMB	Polypoidal tumour	Mixture of cartilage with foci of calcification, bone with marrow, fat, mesenchyme and lymphoid aggregates.	Left pneumonectomy.	No
Sharkey et al 199629	53/M	Haemoptysis	LUL	Pulsatile lesion	Lobules of hyaline cartilage intermixed with compressed glandular epithelium.	Left upper lobectomy.	No
Ortiz-Saracho et al 199330	64/M	Cough, chest pain	RLL	Polypoidal tumour	Hamartoma	Rigid bronchoscopic resection.	No
Sahin et al 198931	60/F	SOB	RLL	Polypoidal tumour	Cartilage-containing mesenchymal tumour, hamartoma.	Rigid bronchoscopic resection.	No
Lee et al 198832	59/F	Cough	RLL	Moveable lobulated pedunculated mass	Multiple hyaline cartilages islands with ossification.	Thoracotomy right middle and lower lobectomy.	No
Frank et al 196633	60/F	SOB	LMB	Polypoidal tumour	Cellular fibrous connective tissue with focal myxomatous change.	Left pneumonectomy.	No
	60/M	Cough, fever	RUL	Polypoidal tumour	Fat, cartilage, fibrous tissue and respiratory epithelium-lined clefts.	Right upper lobectomy.	No
Kurrus et al 196534	68/M	Cough, wheezing, haemoptysis	RIB	Smooth tumour	Degenerated cartilage tissue.	Right middle and lower bilobectomy.	No
	54/M	Cough, weight loss	RMB	Polypoidal tumour	Benign polyp.	Right pneumonectomy.	No
Stengel et al 196435	37/M	Haemoptysis	LMB	Pyramid-shaped white tumour	IsIands of hyaline cartiIage separated by fibrous connective tissue.	Exploratory thoracotomy and a wedge resection. LLL lobectomy for the recurrence.	Yes
Dovenbarger et al 196136	36/M	Cough, chest pain	RUL	Pink, granular tumour	Ossification with formation of marrow spaces and cartilage. Presents of connective and fat tissue, pseudostratified epithelium and myxomatous interstitium.	Right upper lobectomy.	No
	53/M	Cough, chest pain	RIB	Endobronchial tumour	Cartilage, fat and blood vessels.	Bronchotomy with excision.	No
Shields et al 195837	61/M	Cough, haemoptysis	LLL	Pink, glistening, polypoidal tumour	Islands of cartilaginous tissue within a mesenchymal stroma.	LLL superior segmentectomy.	No

F, female; HPE, histopathological examination; LLL, left lower lobe; LMB, left main bronchus; LUL, left upper lobe; M, male; RIB, right intermedius bronchus; RLL, right lower lobe; RMB, right main bronchus; RUL, right upper lobe; SOB, shortness of breath; VATS, video-assisted thoracic surgery.

The flexible cryoprobe can be used in combination with either the rigid or flexible bronchoscope for removal of the endobronchial tumour and it has been shown to have good safety profile, high success rate and immediate treatment effect.⁷ Our case was suitable for cryotherapy because of the location of the endobronchial tumour which was found narrowly attached at the bronchus.

Learning points.

• Our case highlights the importance of investigating recurrent pneumonia with a flexible bronchoscopy and the safety profile of flexible cryoprobe in combination with flexible bronchoscopy as an alternative treatment option for the removal of endobronchial hamartoma.

• Benign endobronchial tumours such as hamartomas need to be considered in the differential diagnosis of recurrent or non-resolving pneumonia.

• Endobronchial hamartoma carries a good prognosis and low risk of relapse.