Pulmonary nodules

-The same as in adult

1-Tuberculoma.

2-Hamartoma.

3-Carcinoma (not present in pediatric group).

4-Deposits.

5-AVM (feeding artery and draining vein).

6-Hydatid cyst.

-A nodule with smooth edge and contains calcium is a benign lesion.

The benign lesions are tuberculoma and hamartoma.

-It is not important from the point of view of clinical practice to differentiate between tuberculoma and hamartoma as they are both benign lesions, never turn malignant and do not have clinical treatment.

-Tuberculoma is mainly located in the apical segment of the upper lobe and superior segment of the lower lobe, while hamartoma can occur at any site.

-Calcification occurs in tuberculoma has no special description while that occurs in hamartoma shows classical pop corn appearance.

-Fat is not present in tuberculoma while it is sometimes seen in hamartoma if it is large enough to be seen.

-At the end, differentiation between tuberculoma and hamartoma is not essentials but it could be sometimes suggested.

-Primary complex lesion:

*Solitary small lung nodule(with break down + matrix calcification) known as Gonn's focus or tuberculoma or a patch. 

*Usually sub pleural.

*Large mediastinal nodes may compress the bronchi causing atelectasis.

*Affects pleura.

 *TB primary complex should be considered in the differential diagnosis of mediastinal lymphadenopathy in the pediatric age group.

So if you see a parenchymal lung lesion in a child with mediastinal lymph nodes showing areas of break down and calcification, this appearance could help you to suggest a TB primary complex lesion.

-Multiple lesions are usually suggestive of metastases or AVM, while the rest of the nodules are usually single.

-Causes of ossified or calcified metastases in the chest in a child :

*Osteosarcoma in the form of nodules or masses.