Cellular schwannoma: report of a case diagnosed intraoperatively with the aid of cytologic imprints

A recurrent cellular schwannoma

Cellular schwannoma is an uncommon variant of schwannomas that can occur in a peripheral nerve. Although cellular schwannomas typically do not differ in prognosis from regular schwannomas, they are known to cause local recurrence when not completely resected. Here, we report the case of a patient with cellular schwannoma of the posterior mediastinum, which recurred after 13 years.

Cellular schwannoma arising from sigmoid mesocolon presenting as torsion

Schwannomas are a type of peripheral nerve sheath tumors with clinically indolent behavior. Though, they can occur anywhere in body, the incidence in retroperitoneum, mediastinum, and pelvis is exceedingly rare. We present a case of a 58-year-old female with a massive twisted tumor arising from sigmoid mesocolon. The tumor was diagnosed to be a case of cellular schwannoma, an exceedingly rare tumor in this location with rare presentation.

Low-back pain as the presenting sign in a patient with a giant, sacral cellular schwannoma: 10-year follow-up

Giant sacral tumors present unique challenges to surgeons because there is no established consensus regarding the best treatment options. The authors report on the care of and outcome in a patient presenting with low-back pain only, who underwent preoperative biopsy sampling and subsequent embolization of the feeding vessels of a giant, sacral cellular schwannoma. The main procedure was performed via a combined posterior-anterior approach with complete microsurgical removal of the tumor, without the use of instrumentation, bracing, or adjuvant radio- and chemotherapy. At the 10-year follow-up, no evidence of residual tumor, recurrence, or instability was recognizable. Giant, sacral cellular schwannomas can be aggressively completely removed without any significant morbidity, achieving long-term control of the disease.

Cellular Neurofibroma with Atypia Mimics Sarcoma: Report of a Case with Immunohistochemical Staining Pattern Analysis and Literature Review

A case of two sporadic cellular neurofibromas with atypia and one widespread hyalinization neurofibroma of the lumbar spine in a 51-year-old man without evidence of neurofibromatosis-1 is reported. Cellular neurofibroma with atypia is an unusual variant. The definite criteria for low-grade and high-grade malignant peripheral nerve sheath tumors as well as cellular neurofibroma are not well defined in the literature. The clinical significance of atypical cellular neurofibroma has rarely been systematically studied. To our knowledge, the concomitance of cellular architecture and cytologic atypia is rarely documented, and this is a rare report of atypical cellular neurofibroma. The recognition of this entity is of great importance to both pathologists and clinicians because atypical cellular neurofibroma is clever at masquerading both histologically and cytologically as a sarcoma; therefore, a precise diagnosis of this variant is essential because of the differences in treatment and clinical behavior between benignancy and malignancy. We also examined the immunohistochemical characteristics of CD34 positive cells and focal high expression of p53 up to 73% encountered in our case. To our knowledge, seldom have series or case reports elucidated this phenomenon.

Cytohistologic correlations in schwannomas (neurilemmomas), including "ancient," cellular, and epithelioid variants

Schwannoma accounts for one of the most common benign mesenchymal neoplasms of soft tissues. Although it is well defined in the cytology literature, particular histologic subtypes such as "ancient," cellular and epithelioid variants could be a source of diagnostic difficulties. We have reviewed cytology aspirates and corresponding histologic sections from 34 schwannomas diagnosed at Institut Curie. Histologically, 24 cases were classic, 5 were "ancient," 4 were cellular, and 1 was epithelioid schwannomas. No example of melanotic schwannoma was recorded. Original cytologic diagnosis was schwannoma in 13 (38.2%) cases, benign soft tissue tumor in 11 (32.4%), pleomorphic adenoma in 2 (6%) cases, angioma in 1 (2.9%) case, nodular fasciitis in 1 (2.9%) case, suspicious in 3 (8.8%) cases, and not satisfactory in 3 (8.8%) cases. There were no major differences between classical, "ancient," cellular, and epithelioid variants on cytology smears. Myxoid stroma, mast cells, and intranuclear inclusions were limited to classical subtype. Similarly, cyto-nuclear atypia was more frequent in classical subtype than in other subtypes. Schwannoma should be differentiated from well-differentiated malignant peripheral nerve sheath tumor, neurofibroma, and pleomorphic adenoma, in the last instance particularly for head and neck lesions.