Perineal schwannoma

Giant Perineal Plexiform Neurofibroma in an 8-Year-Old African Male

The perineal presentation of plexiform neurofibroma is exceptional, with only two cases reported to date. We present an 8-year-old African male with a large perineal tumor of years of evolution. He had no associated symptoms. Café au lait stains were observed on examination, without other findings of relevance. The patient had no preoperative radiological studies. Partial excision of the lesion was performed. Histopathological study of the specimen revealed a plexiform neurofibroma. The lack of diagnostic suspicion due to the atypical nature of the location, the anatomical complexity of surgical resection and the potential urological and rectal involvement make this lesion a diagnostic-therapeutic challenge. Among the differential diagnoses, schwannoma, congenital lipoma, hamartoma and lipoblastoma should be considered.

Spindle cell proliferations of the sigmoid colon, rectum and anus: a review with emphasis on perineurioma

A wide range of spindle cell proliferations are found uncommonly in the sigmoid colon, rectum and anus. They usually present as polyps, and include reactive lesions and benign and malignant neoplasms which may be primary or metastatic. They are less frequently described in the literature compared to those in the upper gastrointestinal tract, and may be underdiagnosed. The widespread use of sigmoidoscopy in symptomatic patients and bowel cancer screening programmes means that histopathologists must be aware of, and adopt a logical approach to, diagnosing spindle cell proliferations in biopsy and polypectomy specimens. This is particularly relevant given the strong association of some mesenchymal polyps with hereditary cancer syndromes. This review article will focus on perineurioma and the recent debate in relation to its overlap with fibroblastic polyp. The clinical, endoscopic, histological and immunohistochemical features of spindle cell proliferations which should be considered in the differential diagnosis of perineurioma will be discussed. There is also a brief reference to malignant spindle cell tumours of diagnostic importance.

Perineal schwannoma: A case report with novel genitourinary association and histopathology

We describe a 39-year-old male patient who presented with a large perineal mass found to represent an entity rarely seen involving the genitourinary tract, a perineal schwannoma. We also provide a discussion regarding the common presentation, diagnostic approaches and treatment options for patients who present with this rare entity.

Primary adrenal schwannoma: a series of 31 cases emphasizing their clinicopathologic features and favorable prognosis

PURPOSE

Primary adrenal schwannoma (PAS) is a very rare benign tumor, and most of them have been described in case reports. This study aimed to analyze their distinct clinicopathologic features and follow-up data through the largest series yet.

METHODS

Clinicopathologic features of 31 primary adrenal schwannomas were retrospectively studied. Imaging and histologic features were re-evaluated and summarized. Immunohistochemical markers were measured, including S100, SOX10, AE1/AE3, EMA, SMA, Desmin, HMB45, GLUT1, and Ki67. Follow-up of all cases was performed.

RESULTS

All the tumors were clinically misdiagnosed as nonfunctioning adrenal adenoma (NAA; 23/31), aldosterone-producing adenoma/aldosteronoma (APA; 3/31), cortisol-producing adenoma (CPA; 3/31), or pheochromocytoma (PCC; 2/31). Some 87% (27/31) presented with adrenal incidentaloma, and 13% (4/31) had a clinical symptom or unregulated hormone levels. They comprised conventional (19/31), cellular (7/31), plexiform (2/31), ancient (1/31), epithelioid (1/31) and microcystic/reticular variants (1/31) and had various histologic features. Immunohistochemically, all tumors (31/31) were positive for S100 and Sox10, with a low Ki-67 proliferative index. In the long-term follow-up (mean, 53 mo.; median, 56 mo.), none had evidence of recurrence and metastasis. Univariate analysis showed that OS and DFS were not associated with age; sex; tumor side, size, or number; adrenal-related symptoms; gross feature (solid vs. cystic); or any histologic feature (P > 0.9999).

CONCLUSION

PAS is an extremely rare tumor and mostly appears as an incidentaloma. Clinically, it tends to be misdiagnosed as other common adrenal tumors. This tumor has a benign biologic behavior and prognosis, without correlations with clinical or histologic parameters.

Ischiorectal fossa: benign and malignant neoplasms of this "ignored" radiological anatomical space

PURPOSE

To review the pertinent anatomy and the imaging features of common and uncommon benign and malignant neoplasms and masses of the ischiorectal fossa.

RESULTS

The ischiorectal or ischioanal fossa is the largest space in the anorectal region. The benign neoplasms that develop in the ischiorectal originate from the different components that forms the fossa including vascular tumors such as aggressive angiomyxoma or hemangioma; neural tumors as plexiform neurofibroma or schwannoma; fat tumors as lipoma; skin/skin appendages tumors as hidradenoma papilliferum; smooth or skeletal muscle tumors as solitary fibrous tumor. The malignant neoplasms that develop in the ischiorectal fossa also originate from different components that forms the fossa including vascular tumors such as angiosarcoma, neural tumors as malignant granular cell tumor and malignant peripheral nerve sheath tumor; fat tumors as liposarcoma; smooth or skeletal muscle tumors as leiomyosarcoma, rhabdomyosarcoma, malignant PEComa, or undifferentiated pleomorphic sarcoma. Additionally, the ischiorectal fossa can also harbor secondary hematogenous metastases and be affected by direct invasion from neoplasms of adjacent pelvic organs and structures. Furthermore, other miscellaneous masses can occur in the ischiorectal fossa including congenital and developmental lesions, and inflammatory and infectious processes.

CONCLUSION

Knowledge of the anatomy, and the spectrum of imaging findings of common and uncommon benign and malignant neoplasms of the ischiorectal fossa is crucial for the radiologists during interpretation of images allowing them to make contributions to the diagnosis and better patient management.

Magnetic resonance imaging findings for differential diagnosis of perianal plexiform schwannoma: Case report and review of the literature

Plexiform schwannoma is an extremely rare variant of schwannoma, accounting for approximately 5% of cases. Due to the rarity and lack of typical symptoms, signs and radiological images, a definite diagnosis of plexiform schwannoma may not be made by clinicians prior to biopsy. In the present study, we report the first case (to our knowledge) of perianal plexiform schwannoma arising from the overlapped skin of the ischioanal fossa, and we propose an intratumorally nonenhanced circumferential capsule dividing the tumour into multiple homogeneously enhanced nodules as a magnetic resonance imaging feature to aid in the differential diagnosis of plexiform schwannoma from ancient schwannoma, cavernous haemangioma, liposarcoma and plexiform neurofibroma.

Perineal schwannoma: an unusual tumor and clinical presentation – first case with erectile dysfunction associated with this neoplasm

Introduction:

Perineal schwannomas (PS) are very rare benign tumors with few cases reported in literature and none of these reports erectile dysfunction among clinical presentations.

Case description:

We report a case of PS with unusual clinical presentation showing erectile dysfunction associated with perineal pain and discomfort during defecation, and the postoperative residual pain and erectile dysfunction treatment.

Conclusions:

On the basis of a literature review of all cases reported and on our case reported, we have delineated a clinical, diagnostic, and therapeutic profile of PS, summarized in a useful table.