ancient schwannoma

Digital slides

 JRC:3076 : Schwannoma with degenerative changes ("ancient schwannoma").
 JRC:14599 : Schwannoma with degenerative changes ("ancient features").
 JRC:397 : Ancient schwannoma with bizarre giant cells - Peritoneum (pelvis)

Definition: Schwannomas are encapsulated benign tumors arising from nerve sheath cells; the ancient schwannoma is one of the five variants.

Ancient change in a schwannoma is a histological variant that is typically found in long-standing tumors, and is thought to result from degenerative changes.

Localization

Ancient schwannoma of the neck region is a rare benign neoplasm derived from neural crest cells and is usually solitary., only a few ancient schwannomas have been reported in different locations in the neck region. Ancient schwannomas of the neck are frequently misdiagnosed, and preoperative investigations are therefore often fruitless.

A significant percentage of ancient schwannomas are located in deep locations such as the retroperitoneum.

Microscopy

Ancient schwannomas are neurilemmomas that display pronounced degenerative changes.

Degenerative changes include cyst formation, calcification, hemorrhage, and hyalinization. One of the most misleading aspects of this tumor is the degree of nuclear atypia. These tumors behave as ordinary neurilemomas and therefore the nuclear atypia can be regarded as a purely degenerative change.

Many of the schwannoma cell nuclei can be large, hyperchromatic, pleomorphic and, often, multilobated. These nuclear features are known as degenerative nuclear atypia.

Differential diagnosis

The histopathological features such as degeneratve changes and nuclear atypia in ancient schwannomas may easily lead to a diagnosis of malignant mesenchymal neoplasm.

Absence of necrosis, mitosis, and invasiveness, as well as the absence of abrupt transition between typical schwannoma areas and cellular foci of atypical large cells support the diagnosis of ancient schwannoma.

See also

 schwannomas

References

 Ancient schwannoma of the neck mimicking soft tissue sarcoma. Bindra R, Gupta S, Gupta N, Asotra S, Sharma A. J Cancer Res Ther. 2010 Apr-Jun;6(2):234-5. PMID: 20622379 [Free]

 Ancient schwannoma of lumbar spine and review of the literature on paraspinal tumors, the role of preoperative biopsy: a case report. Antonopoulos C, Lilimpakis C, Karagianni M, Daskalopoulou D, Kyriakou T, Vagianos C. Cases J. 2009 Dec 15;2:9325.PMID: 20072675 [Free]

 Benign ancient schwannoma of the abdominal wall: an unwanted birthday present. Bhatia RK, Banerjea A, Ram M, Lovett BE. BMC Surg. 2010 Jan 6;10:1.PMID: 20053289 [Free]

 Diagnosis and management of retroperitoneal ancient schwannomas. Choudry HA, Nikfarjam M, Liang JJ, Kimchi ET, Conter R, Gusani NJ, Staveley-O’Carroll KF. World J Surg Oncol. 2009 Feb 2;7:12. PMID: 19187535 [Free]