Pediatric Mediastinal Teratoma

Etiology: contains endoderm, mesoderm, ectoderm tissue and therefore classically can contain fat and calcium
Layers and what comes from them
— Ectoderm – neural, epidermis
— Mesoderm – bone, muscle, connective tissue, dermis, cardiovascular system, reproductive system, kidneys
— Endoderm – epithelium gastroinstestinal / respiratory / genitourinary, endocrine glands
Imaging: anterior mediastinal mass arising from thymus which is often heterogenous and may contain fat and calcium

Radiology Cases of Mediastinal Teratoma

CT of mediastinal teratoma — Axial CT without contrast of the chest shows an anterior mediastinal mass containing soft tissue and fat.

CT of mediastinal teratoma — CXR (above left) shows a mass in the left hemithorax. Coronal (above right), axial (below left) and sagittal (below right) CT with contrast of the chest show a large mass of soft tissue and fat density in the anterior mediastinum that compresses the left lung posteriorly and causes mediastinal shift to the right.

CXR and CT of teratoma of thymus — CXR AP+lateral shows a large anterior mediastinal mass. Axial CT with contrast of the chest shows a heterogenous mass containing low density fat and high density calcium.

CXR and CT of mediastinal teratoma — CXR AP and lateral (above) shows a large anterior mediastinal mass causing tracheal deviation to the right. Axial CT without contrast of the chest (below left) shows the mass to be low density and to contain calcium. Axial CT with contrast of the chest (below right) shows the mass to have rim enhancement and to be primarily fluid-filled.

Gross Pathology Cases of Mediastinal Teratoma

Specimen radiograph of thymic teratoma / mediastinal teratoma — Specimen radiograph shows densely calcified rectangular structures in the resected thymic mass which turned out to be teeth.

Pathology image of mediastinal teratoma — Gross pathological image (above) shows a large heterogenous mixed cystic and solid mass. Specimen radiograph (below) shows multiple fine and coarse calcifications within the mass.

Pathology image of pericardial teratoma — Post-mortem pathological image shows a large heterogenous mixed cystic and solid mass arising from the pericardium of the heart.