Microscopic Description:

Interlacing fascicles of spindle cells with varying degrees of nuclear atypia.

Mitotic activity ranging from 1 to 42 mitotic figures per 10 high power fields (HPF), with a mean of 12 MF/10 HPF.

Coagulative tumor necrosis present in approximately 78% of cases.

Tumors are classified as either high-grade or low-grade based on nuclear atypia, mitotic activity, and tumor necrosis.

Immunohistochemical staining characteristics include:

  • Actin positivity in 83% of tumors.
  • Desmin immunoreactivity in 39% of tumors.
  • Negative staining for epithelial markers and S-100.
  • MIB-1 staining indicating proliferative activity, ranging from 0.1% to 51.4%, with a median of 9.1%.
Discussion:

Age: Leiomyosarcoma of the bladder neck primarily affects older adults, with the median age at diagnosis typically ranging between 63 and 65 years.

Gender: There is a slight male predominance in the incidence of this condition, with a male-to-female ratio of approximately 2:1. This suggests that men may be at a somewhat higher risk for developing this rare tumor.

General Outlook: The prognosis for patients with leiomyosarcoma of the bladder neck is generally poor, primarily due to the tumor's aggressive nature and high potential for both local recurrence and distant metastasis.

Rare malignant smooth muscle tumor located where the bladder connects to the urethra.

Characterized by aggressive behavior and poor prognosis, especially when high-grade.

Symptoms include: hematuria, dysuria, and pelvic pain.

Diagnosis is confirmed by histopathological examination after transurethral resection of the bladder tumor (TURBT).

Treatment is Surgical resection (partial cystectomy to radical cystectomy based on disease extent) and/or adjuvant therapies (radiation and chemotherapy) for high-grade or advanced cases.

Genetic predispositions have been identified in mutations of the RB1, TP53, and PTEN genes, as well as alterations in the TP53 gene.

References:

Cope, B. M., Traweek, R. S., Lazcano, R., Keung, E. Z., Lazar, A. J., Roland, C. L., & Nassif, E. F. (2023). Targeting the Molecular and Immunologic Features of Leiomyosarcoma. Cancers, 15(7), 2099–2099. https://doi.org/10.3390/cancers15072099

Dayron Rodríguez, Preston, M. A., Barrisford, G. W., & Feldman, A. S. (2014). MP50-07 CLINICAL FEATURES OF LEIOMYOSARCOMA OF THE URINARY BLADDER: ANALYSIS OF 183 CASES. The Journal of Urology, 191(4S). https://doi.org/10.1016/j.juro.2014.02.1128

Lee, T. K., Miyamoto, H., Osunkoya, A. O., Guo, C. C., Weiss, S. W., & Epstein, J. I. (2010). Smooth Muscle Neoplasms of the Urinary Bladder: A Clinicopathologic Study of 51 Cases. The American Journal of Surgical Pathology, 34(4), 502–509. https://doi.org/10.1097/pas.0b013e3181cf326d

Lindberg, M. R., Fisher, C., Khin Thway, Cao, D., Cheville, J. C., & Folpe, A. L. (2010). Leiomyosarcoma of the urinary bladder: a clinicopathological study of 34 cases. Journal of Clinical Pathology, 63(8), 708–713. https://doi.org/10.1136/jcp.2010.077883

Martin, S. A., Sears, D. L., Sebo, T. J., Lohse, C. M., & Cheville, J. C. (2002). Smooth Muscle Neoplasms of the Urinary Bladder. The American Journal of Surgical Pathology, 26(3), 292–300. https://doi.org/10.1097/00000478-200203000-00002

CASE IMAGES