Vascular and morphological changes in the urinary bladder wall after irradiation

Radiation or Chemotherapy Cystitis With “Pseudocarcinomatous” Features

BACKGROUND

The features of radiation or chemotherapy cystitis mimicking invasive urothelial cancer are not widely known.

DESIGN

A search of the consultation files from our institution between January 1996 and September 2003 identified 20 patients with bladder biopsies showing cystitis mimicking invasive urothelial cancer.

RESULTS

The mean age at diagnosis was 69 years (range, 40-85 years); 80% were males. Complete history was not available in 1 patient. Seventeen patients had a history of pelvic irradiation (15 prostate cancer and 2 endometrial cancer). Two patients had systemic chemotherapy (1 metastatic colon cancer and 1 mixed connective tissue disease). All patients presented with hematuria. The mean time from radiation and/or chemotherapy to presentation was 27 months (range, 0-84 months). All cases showed epithelial proliferation that mimicked invasive cancer within the lamina propria, with marked proliferation seen in 45% of cases. Mild to moderate nuclear pleomorphism was seen in all cases. A characteristic feature was the presence of pseudoinvasive urothelial nests wrapping around the vessels associated with fibrin deposition. Most cases did not show any mitoses (75%). Ulceration was seen in 39% of cases. All cases showed some degree of hemorrhage, fibrin deposition and fibrin thrombi, fibrosis, and acute and chronic inflammation, with hemosiderin identified in 60% of cases. Edema and vascular congestion were common features (95% and 80%, respectively). Thickened vessels and vascular changes associated with radiation injury were identified in 75% of cases. Seventeen patients were followed for a mean of 9 months (range, 0.25-37 months), and none developed bladder cancer.

CONCLUSIONS

Radiation or chemotherapy cystitis can show epithelial proliferations that may be confused with invasive urothelial carcinomas. Other findings characteristic of radiation or chemotherapy cystitis, such as hemorrhage, fibrin, and vascular changes, are often seen in association with the epithelial proliferations and are helpful in distinguishing it from invasive cancer. Pathologists must be aware that these changes may be seen with a remote radiation or chemotherapy history, where this information may not be provided or known at the time of the biopsy evaluation.

Changes produced in the urothelium by traditional and newer therapeutic procedures for bladder cancer

A handful of traditional and newer therapeutic procedures, such as chemotherapy, immunotherapy, radiotherapy, photodynamic and laser treatment, and gene therapy, are used to treat epithelial malignancies of bladder origin. These treatment modalities, used either intravesically or systemically, produce morphological changes in the urothelial mucosa that can be mistaken for carcinoma. The pathologist must be able to separate toxic and drug related alterations from tumour related changes. The clinical history is usually invaluable in this assessment.

Bladder treatment. Immunotherapy and chemotherapy

The urinary bladder is affected by numerous treatments, including surgery, chemotherapy radiotherapy, photodynamic and laser therapy, and immunotherapy. The literature on therapy for bladder cancer is abundant but tends to offer little information concerning the tissue and cellular manifestations related to treatment. A variety of changes in urothelial cells may be seen on urinary cytology or biopsy. Therapy-associated cytologic abnormalities remain the most common cause of false-positive reports in urothelial cytology. Most pathologic changes are characterized by an exuberant inflammatory reaction, blood vessel abnormalities, and degenerative/regenerative urothelial atypia; none of these findings are diagnostic of the outcome of a specific therapy.

Effects of irradiation on canine tracheal epithelium: a physiological and morphological correlate

We delivered 20 Gy irradiation in one fraction to a 6 cm segment of trachea in 11 dogs. Tracheal mucous transport was studied before and whenever possible at weekly intervals after irradiation using a gamma camera system and 99m technetium labeled sulfur colloid. Ten of the eleven animals were sacrificed at three different time intervals (1-2, 15-16 and 30-34 weeks) post-irradiation, and the tracheal epithelium removed for studies using Ussing chambers followed by preparation for microscopic analysis. Mucous transport along the length of the trachea was normal before irradiation, but following irradiation it became abnormal in the irradiated zone. Compared to the epithelium from the cranial and caudal segments, the irradiated epithelium had similar bioelectric measurements (potential difference, short-circuit current and resistance) and mannitol permeability. Also, the changes in the bioelectric measurements following indomethacin (10(-6) M) and epinephrine (10(-6) M) used sequentially, were similar in both the control and irradiated tissues. Scanning electron microscopic analysis of the irradiated zone revealed patches of nonciliated epithelial cells among the ciliates. We conclude that irradiation caused a persistent replacement of ciliated cells with nonciliates throughout the entire study period and that this alteration impaired mucous transport but did not affect epithelial ion secretion or barrier function.

Vascular changes in the urinary bladder wall after irradiation (an experimental study in rabbits with angiography and scanning electron microscopy of vascular casts)

Seven adult rabbits were used to study radiation-induced vascular changes in the urinary bladder by angiography and scanning electron microscopy of vascular casts. The angiographic studies, in which a magnification techniques was used, revealed a state of hypervascularization in the irradiated area of the bladder. With the angiographic method, however, it was not possible to visualize specific radiation-induced vascular changes within the irradiated area of the urinary bladder. Scanning electron microscopy of vascular casts made possible a detailed study of finer vessels in which typical radiation changes, teleangiectases, could be demonstrated.