Intralobar Pulmonary Sequestration Harbouring Occult Lung Cancer Therapeutic Implications for a Congenital Malformation Case Report and Review of the Literature
- 1. Division of Thoracic and Hyperbaric Surgery, Medical University of Graz, Austria
- 2. Department of Internal Medicine, Medical University of Graz, Austria
Abstract
Non-small-cell lung cancer within congenital intralobar pulmonary sequestration represents a very rare coincidence. To our best knowledge, only twelve cases of pulmonary neoplasia associated with intralobar sequestration have been published.
A 46 year old female patient, non-smoker, presented with recurrent episodes of fever and fatigue persisting over several months. Routine chest roentgenogram showed a high-density mass in the right lower lobe close to the diaphragmatic surface. CT-scan revealed a 4 x 3 x 8 cm mass in the posterobasal segment of the right lower lobe with systemic arterial supply from two large caliber vessels originating from the celiac artery and draining into the pulmonary vein.
During segmental resection the sequester could not be separated from the diaphragm, a small part of which was also resected. Surprisingly, definitive histopathological examination revealed pulmonary adenocarcinoma pG3, pT3 within the intralobar sequestration. Our case and the review of the cases from the literature underline the suggestion, that pulmonary sequestration should be resected rather than undergoing treatment by embolization.
Citation
Fink-Neuboeck N, Lindenmann J, Smolle E, Maier A, Smolle-Juettner FM (2016) Intralobar Pulmonary Sequestration Harbouring Occult Lung Cancer Therapeutic Implications for a Congenital Malformation Case Report and Review of the Literature. JSM Cardiothorac Surg 1(1): 1002.
Keywords
• Intralobar sequestration
• Extralobar sequestration
• Adenocarcinoma
• Lung cancer
INTRODUCTION
Intralobar sequestration is a rare congenital disorder representing an area of dysplastic, nonfunctional lung within one pulmonary lobe. Usually a lower lobe, predominantly on the left side is affected. The sequester is supplied by an aberrant systemic artery, originating most frequently from the thoracic or abdominal aorta. Drainage is usually toward the pulmonary veins. Though the condition may remain asymptomatic, complications including congestive heart failure due to arteriovenous shunting, recurrent pulmonary infection or hemoptysis can evolve. Extralobar sequestration where the systemically supplied sequester has its own pleural covering and is always draining into the systemic veins, is even more uncommon. With the exception of arterio-venous shunting or bleeding, the condition remains asymptomatic [1,2]. The development of a malignant lung tumour within lung sequester is an uncommon finding [3] with only 13 cases reported in the literature (Table 1).
CASE PRESENTATION
A 46 year old woman, non-smoker, complained about cough, fever and fatigue within the last five months.
CT-scan revealed a 4x3x8cm intralobar sequestration in close contact to the diaphragm. Two aberrant arteries originating from the celiac artery entered the lesion and drained into the pulmonary vein. Bronchoscopy showed regular findings. After preoperative coil embolization to reduce the risk of bleeding [4,5], transection of the atypical arteries and resection of both the posterobasal segment and of the tightly adhering diaphragm was done. The defect was closed by direct suturing. Intraoperative frozen section histology gave no evidence of malignancy.
Surprisingly, by definitive histopathological examination adenocarcinoma pG3, pT3 within the intralobar sequestration, infiltrating the diaphragm was found. Postoperative staging gave no evidence of tumour spread to the mediastinal lymph nodes or of distant metastases. Nevertheless, according to the oncological guidelines right lower lobectomy and complete mediastinal lymph node dissection were done [6]. Histopathological examination confirmed the absence of lymph node metastases. Adjuvant therapy including four cycles of Cisplatin and Navelbine was scheduled. One year after surgery the patient is well and free of tumor recurrence.
Table 1: Clinical and pathological findings and surgery in intra- and extralobar sequestration combined with pulmonary neoplasia.
| Author | Year | Age/ sex | Smoking history | Symptoms | Location of sequestration | Type of sequestration | Type of lung neoplasm | Location of neoplasm | Resection |
| Hertzog | 1963 | 36 f | no infor-mation | pain, malaise | right chest | extralobar | squamous cell carcinoma | within sequester | Resection of sequester |
| Bell-Thomson | 1979 | 69 m | yes | none | RLL | intralobar | squamous cell carcinoma | within sequester | Left lower lobectomy |
| Peros | 1980 | 24 f | no infor-mation | none | LLL | intralobar | squamous cell carcinoma | within sequester | Left lower lobectomy |
| Jüttner | 1985 | 45 m | no | cough, fever | LLL | intralobar | atypical carcinoid | within sequester | Left lower lobectomy |
| Gatzinsky | 1988 | 50 f | no | pain, fever, hemoptysis | RLL | intralobar | adeno-carcinoma | within sequester | Left lower lobectomy |
| Morita | 1994 | 59 m | no infor-mation | fever | LLL | intralobar | squamous cell carcinoma | LUL | 1/2 and 3 left Sleeve segmentectomy, 9/10 left segmentectomy |
| Hekelaar | 2000 | 31 f | cough | LLL | intralobar | lymphoepi-thelioma like carcinoma | within sequester | Segmentectomy 8-10 left | |
| Okamoto | 2005 | 69 m | yes | dyspnea | LLL | intralobar | adeno-carcinoma | LUL | Left upper lobectomy, sequester not removed |
| Lawal | 2011 | 67 m | yes | pneumonia, hemoptysis | LLL | intralobar | adeno-carcinoma | within sequester | Left lower lobectomy |
| Ma | 2011 | 39 f | no | pneumonia | LLL | intralobar | atypical carcinoid | within sequester | Left lower lobectomy |
| Westphal | 2012 | 39 f | no infor-mation | pneumonia cough, fever, hemoptysis | RLL | intralobar | typical carcinoid | intermediate bronchus | Right lower bilobectomy |
| Wang | 2013 | 65 m | no infor-mation | none | LLL | intralobar | adeno-carcinoma | adjacent to sequester | VATS left lower lobectomy |
| Nowak | 2013 | 41 m | no infor-mation | hemoptysis | LLL | intralobar | typical carcinoid | within sequester | Left lower lobectomy |
| Abbreviations: F: Female; M: Male; RLL: Right Lower Lobe; LLL: Left Lower Lobe; LUL: Left Upper Lobe | |||||||||
DISCUSSION
Intralobar pulmonary sequestration is a rare congenital disorder, characterized by a dysplastic area of lung tissue localized within one lobe, the bronchi of which may or may not have secondary contact to the deformed bronchi of the sequester. The latter is supplied by systemic arteries and usually drains into the pulmonary vein and/or the systemic ones. The condition may remain asymptomatic or become clinically apparent because of a significant arterio-venous shunt, hemoptoe or recurrent infections in the dysplastic tissue [1-3,7]. The even more uncommon extralobar sequestration also represents nonfunctional lung tissue, which, however, is covered by its own pleura. The blood supply derives from systemic arteries which always drain into the systemic veins [1].
Bronchogenic carcinoma associated to or lying within in a pulmonary sequestration is very rare. To our best knowledge, only thirteen cases of pulmonary neoplasms associated with pulmonary sequestration have been reported. There were four squamous-cell carcinomas [6,8-10], four adenocarcinomas [11-14], one lymphoepithelioma-like carcinoma [15] and four carcinoids [16-19]. Twelve out of the sequestrations were of the intralobar type nine of which involved the left and three the right lower lobe, one sequester was extralobar, localized in the right pleural cavity. Ten out of the thirteen tumours had developed within or in contact to the sequester, in three cases the tumour was coincidental and involved different lobes (Table 1).
The symptoms covered the range of typical findings attributed to intralobar sequestration such as hemoptysis, cough, fever, pneumonia and pain. Two patients were asymptomatic. Neuroendocrine or “carcinoid” tumorlets are often associated with bronchiectasis and scarring and may be considered as a precursor of carcinoids [20]. Various authors have described their occurrence in intralobar sequestration [21-23]. They suggested chronic hypoxia within the sequester as cause for the formation of the tumorlets. The development of a carcinoid tumour in intralobar sequestrations could be explained by this mechanism. Recent data suggest that ongoing inflammatory reactions in the lungs may be the cause of malignant transformation [24-26]. Thus, also considering the fact that at least 40% of the patients with sequestration and lung neoplasia were nonsmokers, a pathogenetic pathway of chronic infection promoting tumor formation can be suspected. For the incidence of pulmonary neoplasia in sequestration only estimates can be made: Within a series of 45 intralobar sequestrations in adults within 20 years Liu reported one case “accompanied by carcinoid”, corresponding to an incidence of 2.2%. Larger series of intralobar sequestration have only been reported in infants and children who are unlikely to develop pulmonary neoplasia within the malformation.
Though resection is generally considered as the optimum treatment of pulmonary sequestration, recently also endovascular embolization of the atypical feeding arteries has been advocated [27-30]. In view of the possibility of malignancy developing in sequestration, resection – which can also be done thoracoscopically [3,14] - rather than embolization should be preferred in adults as well as in children [7].
