Pseudotumour of renal pelvis: Liesegang rings mimicking a solid neoplasm of the renal pelvis

[Comparative morphological characteristics and immunophenotype of urothelial carcinomas of the renal pelvis and bladder]

Urothelial carcinoma is one of the most frequently diagnosed malignant tumors of the bladder and upper urinary tract, which ranks seventh in the pattern of cancer. Urothelial carcinoma of the renal pelvis is less common; but has a more aggressive clinical course and a worse prognosis than that of the bladder. This is due to the clinical and morphological features of this form of cancer, which, unlike bladder cancer, have not been studied enough.

OBJECTIVE

To comparatively analyze the morphological and immunophenotypic parameters of urothelial carcinomas of the renal pelvis and bladder.

SUBJECT AND METHODS

Surgical specimens from 196 patients diagnosed with urothelial carcinoma of the renal pelvis and bladder were investigated. Paraffin sections were immunohistochemically examined using the standard protocol. Antibodies against CK5/6, CD138, CDX2 ('Dako'), CK7, CK14, CK20, CEA, CD10, CD117, EMA, E-Cadherin, HMWCK, p63, Uroplakin III, Vimentin ('Novocastra'), CD44, GATA-3, MUC1, MUC2, and MUC-5AC ('Cell Marque') were used.

RESULTS

Most tumors (n=147 (75%)) were invasive. Of them, 65 (33%) cases had a histological structure of conventional urothelial cancer; and 3 (1.5%) had paradoxical differentiation. Divergent tumor zones were verified in 66 (34%) neoplasms; 4 (2%) cases showed an inverted growth pattern. Pseudosarcomatous stroma reaction in the invasion zones was verified in 9 (5%) cases. The tumor stage corresponded to pT2-pT4 in 128 (65%) tumors.

CONCLUSION

Urothelial carcinomas of the renal pelvis and bladder show a broad spectrum of histological variants. The findings support that, unlike urothelial carcinomas of the bladder, the majority of primary urothelial carcinomas of the renal pelvis are high-grade and highly invasive.

A benign renal cyst containing liesegang rings mimicking a renal cell carcinoma: a case report

Liesegang rings are uncommon pathological findings which may cause diagnostic dilemmas for pathologists. Awareness of their appearance is important to avoid over diagnosis of parasitic infection, algal contamination and psammoma bodies. Liesegang rings are benign, lamellar structures with radial striations and a central amorphous core. They are found in a variety of tissues and fluids in both an intra- and extra-cellular sites. We present here a case of a cystic renal lesion containing Liesegang rings mimicking a renal cell carcinoma.

Liesegang rings in an apocrine hidrocystoma: a case report and review of literature

Liesegang rings represent an in vivo chemical precipitation phenomenon representing a potential diagnostic pitfall for misdiagnosis as parasitic infections. These acellular patterns of lamellar concretions are rare in human tissue. The authors report a case of Liesegang rings observed within an intradermal apocrine hidrocystoma and review the literature for reports of these structures, with particular emphasis on mucocutaneous lesions.

Biliary deposition of Liesegang rings presenting as a polypoid mass in the liver: previously unrecognized lesion

Liesegang rings (LR) are acellular, laminated structures that may be deposited within and around cysts and inflamed or necrotic tissue. Previous reports have shown that the kidney and breast are commonly affected organs of LR. Herein is reported a rare case of biliary deposition of LR presenting as a tumor-like polypoid mass in the liver. A 70-year-old man was found to have a cystic lesion, measuring 3.0 cm in diameter, in the lateral segment of the liver. The lesion was accompanied by a solid mass, 1.8 cm in diameter, within the cystic cavity. Lateral segmentectomy of the liver was performed because clinical examinations could not exclude the possibility of hepatobiliary cystadenoma or cystadenocarcinoma. Pathology of the resected specimen indicated a soft polypoid mass, connecting to the cystically dilated bile duct with elongated stalk-like structures. Histologically the surface of the mass was covered by non-neoplastic biliary-type epithelium. Beneath the epithelium, extensive deposition of numerous ring-like laminated structures, which exhibited an identical appearance to LR, was observed. This is a unique and previously unrecognized lesion involving the occurrence of LR deposition in the hepatobiliary tracts, which further formed a grossly visible mass resembling a hepatic tumor.

Confocal laser scanning microscopy of liesegang rings in odontogenic cysts: analysis of three-dimensional image reconstruction

Liesegang rings are concentric noncellular lamellar structures, occasionally found in inflammatory tissues. They have been confused with various parasites, algas, calcification, and psammoma bodies. The authors examined Liesegang rings from oral inflammatory cysts by both optical and confocal laser scanning microscopy, and perfomed a three-dimensional reconstruction. These investigations indicate that Liesegang rings are composed of multiple birefringent concentric rings, resulting from a progressive deposition of organic substances, with an unclear pathogenesis.