The rare mediastinal lipoma: a postmortem case report

Abstract

Mediastinal lipomas are extremely rare, so there are few reported cases. We report a postmortem case of this rare intrathoracic lipoma in a 79-year old female cadaver. The gross features of the tumor and histopathological findings confirmed the diagnosis of a massive simple benign lipoma. To our knowledge, this is the first case to be reported at such an advanced age and the second postmortem case found during comprehensive review of literature.

Keywords: Mesenchymal tumors; adipose cells; asymptomatic; resection.

Figure 1

shows in-situ picture of the intrathoracic mass sitting on the left hemidiaphragm in direct contact with the base of left lung (removed) and posteroinferior surface of the heart (removed). The mass slightly pushes the pericardial sac and heart forward (white arrow).

Figure 2

A: shows the removed left lung viewed from its mediastinal surface where the inferior lobe is massively impressed(white arrows) by the intrathoracic lipoma (resected); B: shows the same left lung viewed from its diaphragmaticsurface where the inferior lobe is massively impressed (white arrows) by the intrathoracic lipoma (resected).

Figure 3

A: shows the resected intrathoracic lipoma, which is a pyramidal shape. Its brown-colored base has the pedicle stump where the tumor was resected. The tumor base is concave due to its molding by the upper surface of the left hemidiaphragm. Notice the true glistening capsule surrounding the entire lipomatous mass; B: shows a longitudinal cut section of the lipoma. Notice the pale yellow discoloration of the cut section compared to the brown discoloration of the tumor base and the tumor’s subdivision into multiple lobules.

Figure 4

A: Histopathologic examination of the tumor reveals the mature regular adipose cells of almost similar sizes and eccentric normal nuclei (black arrows). X400; B: A histopathologic section of the tumor shows lipomatous lobules separated by a connective tissue septum. The black arrows show one of the rare occasions of lymphocytic infiltration. The white arrows show one of the sporadic hemorrhages scattered in a few sections. The blue arrows surround limited groups of small, however perfectly normal, adipose cells located mostly towards the center of the tumor. The small-sized adipose cells may be due to peripheral compression and probably limited blood supply, X200.