Pulmonary sequestration associated with aspergillosis

[Morphological features of the pulmonary sequestration]

The pulmonary sequestration corresponds to pulmonary tissue intra or extra-lobar with systemic arterial nutrition and collateral bronchial ramification. It is infrequent and the intra-lobar identification depends on the correct clinical signs and morphology. The correct study includes imagiologic identification of the systemic artery and morphological characterization of parenchymal changes. These allow identification of abnormal pulmonary parenchyma in intra-lobar cases and were observed using histochemical and immunohistochemical routine methods, both in intra and extra-lobar cases. Four cases of intra-lobar sequestration and four cases of extra-lobar sequestration were studied with application of histochemical techniques--Movat's pentachrome stain and Verhoeff--and immunolabelling with CK7 and TTF1. The parenchymal inflammatory distortion by collagenization was constantly seen as was BALT hyperplasia and pleuritis. By using Movat's pentachrome stain we characterized the sequestration by identifying the artery and the parenchymal changes. The CK7 was useful in the identification of parenchymal damage, together with the antibody anti-TTF1 that had a variable expression, stronger in areas of inflammation because of PII hyperplasia.

[The extralobar sequestration of the fetal lung]

The extralobar sequestration is a rare pulmonary malformation. An accurate antenatal evaluation is required for a timely therapy and subsequently a good outcome. Here an unusual case of extralobar pulmonary sequestration in a male human fetus is reported. Antenatal ultrasound at 28th week of gestation has revealed a fetal hydrothorax in coexistence with pulmonary hypoplasia and an isolated pulmonary structure. Authors summarise their postnatal findings with special reference to the pathogenesis of an accessory lung. The aim of this report is to define the association of clinical, gross, and histological features of this rare congential malformation in order to improve the antenatal diagnosis. This case indicates that an extralobar pulmonary sequester is not connected to the tracheobronchial tree, and that the arterial as well as the venous blood supply is realised by aberrant systemic vessels. Moreover, histologically revealed dilatations of the normally differentiated terminal airways within the sequester suggest that hyperechogenity can not be a reliable diagnostic criterion. For the accurate assessment of a pulmonary sequestration a detailed antenatal evaluation of both, the arterial and the venous blood supply is essential.