Published online Feb 7, 2014. doi: 10.3748/wjg.v20.i5.1371
Revised: November 3, 2013
Accepted: December 5, 2013
Published online: February 7, 2014
Microcystic/reticular schwannoma is a recently described variant of schwannoma with a predilection for the gastrointestinal tract. Due to overlapping features with other tumors, unawareness of this tumor type may lead to diagnostic and therapeutic pitfalls. We here report a case of microcystic/reticular schwannoma arising in the meso-appendix of a 43-year-old woman. The tumor was incidentally discovered by computed tomography scan for unrelated reasons. A laparoscopic operation was performed shortly after admission. Histological examination revealed a circumscribed tumor with a striking microcystic and cribriform architecture. Immunohistochemically, the tumor cells were diffusely positive for S100 protein, glial fibrillary acid protein and protein gene product 9.5, which were consistent with a peripheral nerve sheath tumor. The patient remains well with no signs of recurrence at a 10-mo follow-up. To our knowledge, this is the first case of microcystic/reticular schwannoma arising in the meso-appendix. Albeit very rare, microcystic/reticular schwannoma should be included in the differential diagnosis of appendiceal tumors.
Core tip: Microcystic/reticular schwannoma is a recently described variant of schwannoma with a predilection for the gastrointestinal (GI) tract. The striking reticular growth pattern and myxoid background may cause confusion with several other tumors commonly seen in the GI tract, in particular a gastrointestinal stromal tumor with prominent myxoid change and a signet ring cell carcinoma, especially on small biopsies. Herein we report for the first time a microcystic/reticular schwannoma arising primarily in the meso-appendix to highlight its existence and enhance pathologist’s and clinician’s awareness of this under-recognized variant of schwannoma so as to avoid misdiagnosis and mistreatment.