Bladder schwannoma -- a case presentation

Abstract

Bladder schwannomas are exceedingly rare, benign or malignant, nerve sheath tumors that are most often discovered in patients with a known diagnosis of Neurofibromatosis type 1 (NF1). A few sporadic case reports of bladder schwannoma have been published in urologic, obstetric/gynecologic, and pathologic journals. However, this is the first case report in the radiologic literature where computed tomography imaging and radiology-specific descriptions are discussed. Furthermore, the patient presented in this case is only the fifth published patient without NF1 to be diagnosed with a bladder schwannoma, to the best of our knowledge.

Keywords: Bladder mass; bladder schwannoma; neurofibromatosis; schwannoma.

Figure 1

31 year old male diagnosed with a bladder schwannoma. Select axial images from non-contrast abdominal CTs (soft tissue windows) performed on the patient’s first (left) and second (right) visit to the emergency department. The first visit was approximately 3 years prior to his diagnosis of bladder schwannoma, and the second visit was 15 months prior to his diagnosis. No bladder mass is demonstrated on either CT. (Protocol: 16 slice, 120 KVP, 119 mA, 5 mm slice thickness, non-contrast).

Figure 2

31 year old male diagnosed with a bladder schwannoma. Select axial image from a non-contrast abdominal CT in soft tissue windows demonstrates a homogeneous, well-circumscribed, solid mass on the left anterolateral bladder wall (right). A magnified view of the same lesion is also displayed (left). The mass is isodense to the bladder wall and measures 1.7 × 1.1 cm in axial dimension. (Protocol: 16 slice, 120 KVP, 123 mA, 5 mm slice thickness, non-contrast).

Figure 3

31 year old male diagnosed with a bladder schwannoma. Single image obtained during a cystoscopy demonstrates a tan, smooth-appearing, submucosal mass, which has been partially removed during a biopsy procedure.

Figure 4

31 year old male diagnosed with a bladder schwannoma. Low (left) and High (right) magnification hematoxylin and eosin stains from the bladder mass biopsy. Low magnification demonstrates a spindle cell neoplasm with densely cellular areas (Antoni A), loose hypocellular areas (Antoni B), and calcifications. High magnification demonstrates palisading of spindle cell nuclei alternating with nuclear free zones (Verocay bodies) within the Antoni A areas. These pathologic findings are highly characteristic of a schwannoma.