**2. Epidemiology**

Annual incidence which is as high as 13-27 cases per 1, 00,000 population in certain coun‐ tries of central Asia 2. The prevalence have been of pulmonary involvement is reported to be 10% to 40% in different reported series [3].

© 2013 Alloubi; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2013 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

**Figure 2.** operative specimen: adventitia which is the host tissue formed by the lung as a reaction to the foreign body (white arrow) and de germinative membrane ( black arrow); E Boeykens, A. M. Vints University Hospital of Antwerp

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**Figure 3.** Operative view: endocyst layer that gives rise to larval scolices (arrow)

**• type I**: simple cyst with no internal architecture

**◦ type IIa**: round daughter cysts at periphery

**• type II**: cyst with daughter cyst(s) + matrix

Based on morphology the cyst can be classified into 4 different types:

**◦ type IIb**: larger, irregularly shaped daughter cysts occupying almost the entire volume

(with permission)

**3.2. Cyst classification [4]**

of the mother cyst

**Figure 1.** Life cycle (dog-sheep cycle) of *E granulosus.* Diagram shows the most prevalent life cycle of *E granulosus,* in which a dog and sheep serve as the definitive and intermediate hosts, respectively. Radiographics 2000; 20:795–817 (With permission)
