Giant metanephric adenoma, benign tumor with features of clinical and radiological malignancy
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Department of Human Histology and Embryology, University of Warmia and Mazury in Olsztyn, Poland
Department of Physiotherapy, Jozef Rusiecki University College in Olsztyn, Poland
Department of Surgical Oncology, Ministry of Internal Affairs Hospital with Warmia and Mazury Oncology Centre, Olsztyn, Poland
Department of Oncology, Faculty of Medical Sciences, University of Warmia and Mazury in Olsztyn, Poland
Department of Radiology, Faculty of Medical Sciences, University of Warmia and Mazury in Olsztyn, Poland
Department of Pathomorphology, Faculty of Medical Sciences, University of Warmia and Mazury in Olsztyn, Poland
Janusz Godlewski   

Department of Human Histology and Embryology, University of Warmia and Mazury in Olsztyn, Warszawska 30, 10-900 Olsztyn, Poland. Tel.: +48 698 694 528.
Submission date: 2014-11-05
Acceptance date: 2015-04-09
Online publication date: 2015-05-11
Publication date: 2020-03-24
Pol. Ann. Med. 2015;22(1):45–49
Metanephric adenoma (MA) is a rare benign neoplasm, accounting for 0.2% of adult renal epithelial neoplasms. This neoplasm mainly occurs in patients aged 50–60 years.

The aim of this study was presentation of rare kidney tumor assessment to elaborate proper postoperative decisions and further patient's recommendation.

Material and methods:
The case of a 64-year-old woman with MA is presented. Radiological, intraoperative and pathomorphological evaluations of this neoplasm were performed and compared.

Results and discussion:
Primarily performed CT imaging analyzed this tumor as a malignant neoplasm; organ destruction and evident mass invasion in the calyx and kidney pelvis region were noticeable. Regardless of the initial radiological and clinical characteristic, postoperative pathomorphological analyses recognized the benign nature of this tumor; regularly located tubules and small cell regular outlook were observable. Attention was given to a solid fibrous capsule, which separated neoplasm from the rest of the healthy kidney structure. The patient was not qualified for adjuvant therapy, based on the pathomorphological evaluation due to characteristic nature of the benign kidney tumor. Nevertheless, in view of the initial observations (radiological and clinical) and because cases of metastases in the course of MA are described in the literature, a further periodic follow-up was strongly suggested to the patient.

The evaluation of neoplasm tumor requires many analyses. In this rare tumor lack of correlation was observed between radiological and pathomorphological examinations. The clinical decision connected with the patient's recommendation should be based on complete results, especially pathomorphological diagnosis. The patient is now under clinical observation and in six months follow-up has had no neoplasm recurrence or metastasis.

All authors declare no conflict of interest.
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