Answer: Extralobar bronchopulmonary sequestration

Histology: none provided

Discussion: The term pulmonary sequestration is used when a portion of lung tissue does not communicate with the tracheobronchial tree and has a systemic blood supply. They are further subdivided into extralobar or intralobar based on their location (within or outside the visceral pleura of the lung). Our specimen consisted of a portion of hemorrhagic lung parenchyma that was covered by pleura, supplied by thick walled large vessels and clinically located outside the lung thus satisfying the criteria for extralobal sequestration. Extralobar sequestrations are congenital abnormalities, whereas most intralobal sequestrations are acquired. The histologic findings are non-specific and often resemble normal lung, however, when secondary infection is present reactive epithelial changes can be prominent.