Endolymphatic Sac Tumor Associated with a Von Hippel-Lindau Disease Patient: An Immunohistochemical Study

Abstract

The authors report a case of endolymphatic sac tumor (ELST) associated with Von Hippel-Lindau disease (VHL). A 20-year-old female VHL patient received a resection of a cerebellar hemangioblastoma 3 years ago and she had a co-existing of left petrous tumor. The petrous tumor showed a remarkable progression in 3 years and was resected subtotally. Histologically, the resected petrous tumor showed a papillary structure containing cuboidal or columnar cells with fibrous stroma and numerous microvessels and destructed temporal bone, all of which are consistent with ELST. We studied the expression of various kinds of cytokeratins (CKs) immunohistochemically and found distinct expression of CKs (CAM 5.2, 34␤E-12, CK7, CK8 and CK19), but not for CK10/13 or CK20. Vascular endothelial growth factor and neuron specific enolase showed strong immunoreactivity in the tumor cells. CD34 also had weak expression. Ki-67 antigen (MIB-1) immunoreactivity was found in focal areas, and the labeling index in the highestdensity area was 48.9%. These findings suggest that vascular endothelial growth factor overexpression is an important factor for angiogenesis in ELST, much like other VHL-associated tumors, and that ELST may have a more highly aggressive component than the low-grade malignancy noted in previous reports.

Abordaje multidisciplinar al tumor de saco endolinfático

“…La inmunohistoquímica puede mostrar positividad hacia anticuerpos enolasa específicos, factor de crecimiento endotelial vascular, antineurona, vimentina, S100, anti antígeno de membrana epitelial o proteína ácida fibrilar de la glía 8,9,11,15 . Podemos hallar positividad para citoqueratinas CAM 5.2, 34betaE-12, CK7, CK8 y CK 19 pero no para CK 10/13 o CK20.…”

“…Podemos hallar positividad para citoqueratinas CAM 5.2, 34betaE-12, CK7, CK8 y CK 19 pero no para CK 10/13 o CK20. En áreas focales se puede hallar inmunorreactividad para el antígeno Ki-67 (MIB-1) 9 . Se diagnostica un tumor del saco endolinfático por reacción positiva a marcadores de neuroectodermo y epiteliales y negativa a marcadores neuronales 11 .…”

Endolymphatic sac tumour (ELST). of a rare tumour of the temporal bone, presenting as a mass in a cerebello-pontine angle

“…It is characterized by highly vascularized, poorly circumscribed proliferation of cuboidal epithelial cells forming a papillotubular pattern and occasional colloidfilled cysts. These formations are lined by a single row of cuboidal to low columnar or more flattened epithelial cells with eosinophilic or vacuolated cytoplasm [16,20]. The proportions of clear cells, follicle-like structures and of tumour stroma is variable [15,18,31].…”

Endolymphatic Sac Tumors : Report of Four Cases

“…Nearly all ELST express cytokeratin, vimentin, and epithelial membrane antigen, and most stain positive for S-100 and neuron-specific enolase 4,8,13,16,18) .…”