Hyperkeratose der Harnblase

Zusammenfassung

Hyperkeratosen im urologischen Fachgebiet sind meist auf das äußere Genitale beschränkt. Eine hyperkeratotische Veränderung innerhalb des normalerweise mit Urothel ausgekleideten Hohlsystems wurde in der vorliegenden Weltliteratur nicht beschrieben. Die einzige Verbindung findet sich in der gehäuften Kombination einer palmoplantaren Hyperkeratose der Haut mit dem gehäuften Auftreten von Harnblasenkarzinomen. Lokalisierte mikroskopische Keratinisierungen einer Leukoplakie wurden beschrieben [1] [3]. Eine makroskopische Hyperkeratose innerhalb der Harnblase wurde jedoch nicht beschrieben. Es ist deshalb von Interesse, das von uns beobachtete Krankheitsbild einer 36-jährigen Patientin vorzustellen.

Abstract

Hyperkeratosis is rare in urologic disciplines and is then usually confined to the external genitalia. Hyperkeratotic changes within the vesicular system, which is normally lined with urothelium, have not been previously described in the world literature. The only connection is found in the frequent combination of palmoplantar skin hyperkeratosis and common cancer of the urinary bladder. Localized microscopic keratinization in leucoplakia has been described. Macroscopically visible hyperkeratosis within the urinary bladder has not been described. We would like to introduce a 36-year-old female with this hyperkeratosis of the bladder.

Hyperkeratosis is constituted by a disruption in keratinization and a thickening of the horny layer of the epidermis. A distinction is made between proliferative hyperkeratosis (often the result of hornification or keratinization) and retention hyperkeratosis (brought about by reduced desquamation). Hyperkeratosis of the skin can be evoked by exposure to various chemical substances.

In addition to transitional epithelium, squamous epithelium is also found occasionally within the urinary bladder. Squamous cell carcinoma can result from this in up to 3 % of patients with all types of carcinoma of the bladder. Theoretically, therefore, it is possible - although unlikely - for all other changes which are observed in squamous epithelium to appear within the urinary bladder as well.

A conceivable pathogenetic mechanism in the development of intravesical hyperkeratosis would be a change in the urinary bladder, e.g. squamous epithelial metaplasia (rarely accompanied by intravesical squamous cell carcinoma). Keratinization is to be expected as a further rare event during this formation of squamous epithelium, with subsequent keratinization.

Hyperkeratosis, which is otherwise found only in the area of the epidermis, must be regarded as one such change of the squamous epithelium. The hyperkeratosis in the case reported here was comparable to hyperkeratosis of the palms and soles, since there were no pathohistologic signs of precancerous conditions like leucoplakia, Bowen's disease, senile keratosis, arsenic keratosis or pitch warts.

The basic pathophysiologic model has a certain probability, but has not been confirmed.

In summary, the present case was a form of hyperkeratosis of the urinary bladder that has not been previously described in the world literature. In addition, there were no manifestations whatever anywhere on the surface of the body.

Key words:

Urinary bladder - Keratosis

Literatur

• 1 Iritani Y, Maekawa M, Sugimura K, Hanada M, Nakanishi J. A case of “verrucous hyperplasia”; a vesical leukoplakia showing unusual macroscopic and histological findings.  Hinyokika-Kiyo. 1984;  30 803-808
• 2 Jung E G. Dermatologie. Stuttgart: Hippokrates Verlag 1989: 210
• 3 Kuruvilla S, Ramakrishna B, Nath V. Keratinising squamous metaplasia of the urinary bladder.  Indian J Pathol Microbiol. 1994;  37 Suppl. 39-40