A case of aspergillosis associated with intralobar pulmonary sequestration

Introduction

Pulmonary aspergillosis (PA) generally results from the colonization of a pre-existing lung cavity or of a bronchiectatic lesion by the ubiquitous Aspergillus fungi species. PA often requires surgical intervention when there is a risk of sudden life-threatening hemoptysis or when antifungal agents are not effective.

We report a case of PA associated with intralobar pulmonary sequestration (IPS), which is an uncommon congenital malformation characterized by a non-functional lung lesion that does not communicate normally with the bronchial tree.

Case description

A 32-year-old man was admitted with complaints of blood-stained sputum. Physical examination was normal. A chest X-ray revealed a left retrocardiac shadow. A computed tomography (CT) showed the lesion to be heterogeneous, suggesting the possibility of an infection or lung cancer. Biochemical and hematological analysis did not detect any abnormalities but serum b-D-glucan was found to be 130 pg/ml (normal range, <20 pg/ml). The patient tested positive for antigens specific to the Aspergillus species. No abnormality was found in the other organs. A diagnosis of PA was made and he was administered itraconazole (200 mg/d) for 12 months. Serum b-D-glucan decreased to 25.9 pg/ml, but the shadow in the left lower lobe remained (Figure 1), and serum carbohydrate antigen (CA19-9) was found to be 105.3 units/ml (normal range, <37.0 units/ml). Angiography (Figure 2) revealed a large anomalous artery originating from the descending thoracic aorta and coursing into the left lower lobe. The patient was diagnosed with PA associated with IPS, and an open thoracotomy was performed.

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Figure 1.

Chest CT showing infiltrative shadow in the left lower lobe.

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Figure 2.

An aortography showing an aberrant artery from the descending thoracic aorta.

At exploration, a gross mass was palpable in the left lower lobe. After careful separation of the adhesion between the lobe and the chest wall, the feeding artery from the descending aorta was easily identified and was then carefully dissected out and divided. A left lower lobectomy was performed without further difficulty.

The macroscopic findings of the resected specimen consisted of a partly consolidated parenchyma with a dilated bronchus (Figure 3). A histopathological study revealed that the lesion was caused by IPS with bronchiectasis and that it was filled with a mucinous fluid from which Aspergillus fumigutus was cultured. There was no malignant finding in the resected lung. One month after the operation, serum b-D-glucan and CA19-9 decreased to 6.0 pg/ml and 7.9 units/ml, respectively.

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Figure 3.

Resected specimen showing a partly consolidated parenchyma with dilated bronchus (arrow), which was filled with gray mucinous pus.

The patient was uneventfully discharged on the 12th postoperative day and has been in good health without recurrence of PA or any other respiratory infection.

Discussion

This case is interesting because of the association of PA with IPS and because of the reduction of preoperative level of the serum tumor marker CA 19-9 to the normal level after the resection of the IPS associated with aspergillosis.

IPS is a congenital malformation that is characterized by a non-functional lung lesion that does not communicate normally with the bronchial tree. In this condition, an aberrant systemic artery arising from the aorta or one of its branches supplies a part of the lungs. These malformations are rare and usually present in early childhood as recurrent chest infections. Because of recurrent infections, the definitive treatment of IPS is surgical resection. ¹

We made an initial diagnosis of PA and administered an antifungal agent. But no aberrant artery was detected on chest CT scan. When aspergillosis is localized and antimycotic drugs are ineffective, complete resection of the infectious lesion is the best treatment. ^2,3 Therefore, since the antifungal agent was ineffective, we considered surgical intervention for the alleviation of the symptoms and the control of pulmonary infection. During the preoperative examination, an aberrant artery was noticed. Had the pulmonary resection been performed without knowledge of the systemic supply to the left lower lobe, the abnormal artery might have caused fatal bleeding during the surgery. Therefore, it is important to bear in mind that IPS may be masked by a prolonged and refractory infectious lesion in the lower lobe, which is a common site of IPS.

IPS is a benign disease, but some reports have indicated that pulmonary sequestration tends to increase the level of serum tumor markers. ^4,5 However, there is no clear explanation how the serum tumor marker level is increased in IPS. In the present case, the increased preoperative level of serum CA 19-9 decreased to within normal limits after surgery. Further, no malignant region was observed in the specimen. On the other hand, some cases of IPS associated with lung cancer have been reported. ⁶ Thus, even after a diagnosis of IPS, the possibility of the occurrence of malignant disease must be kept in mind.