AB 29. Malignant mediastinal tumor: restrictions in
Background: It is common ground that immmunohistochemistry’s
contribution in neoplasm’s origin identification is invaluable. However,
in some cases there seem to exist certain limitations raising differential
Patients and methods: A young 23-year old woman, who was recently
pregnant and breastfeeding, presented to our hospital with dyspnea
and superior vena cava syndrome. A month ago she suffered from
upper respiratory tract infection, which was treated with antibiotics. Axial computed tomography showed several mediastinal masses and
right lower lobe lung invasion. This was followed by bronchoscopy and
samples were taken for biopsy.
Results: Upon histological evaluation a malignant neoplasm with
extensive necrosis was revealed. Diffuse distribution of oval, middle
to large size cells, with conspicious nucleoli and mitoses, tend to lead
to the diagnosis of a lymphoproliferative neoplasm. During to gradual
and extensive immunohistochemical examination, the neoplastic cells
were found negative to stains specific for hemopoietic system diseases
as well as other malignant neoplasm such as sarcoma, mesothelioma,
germ cell tumor, melanoma and neuroendocrine carcinoma. On
the other hand, they were strongly positive for p63 (squamous
cell differentiation index), CD138 and only weak and focally for
keratins (CKAE1/AE3, CK8/18, CK7, CK5/6). Morphological
and immunohistochemical findings consisted with undifferentiated
carcinoma, with squamous cell differentiation. The patient deceased
20 days later.
Conclusions: Neoplastic morphological features tend to lead to a correct
diagnosis which should always be certified by immunohistochemical
findings. However, in some cases immunohistochemistry’s role is
diminished due to tumor specific factors as neoplastic cells’ poor
differentiation or dedifferentiation and degenerative changes.
Cite this abstract as: Pastelli N, Baliaka A, Cheva A, Konstantinou E, Kalaitzidou
E, Sakkas L. Malignant mediastinal tumor: restrictions in immunohistochemical
evaluation. J Thorac Dis 2012;4(S1):AB29. DOI: 10.3978/j.issn.2072-1439.2012.