Cystic Nephroma Research Articles

Pulmonary cysts in early childhood and the risk of malignancy

Surgery for congenital and early childhood lung cysts is often dictated by symptoms such as respiratory distress, infection or pneumothorax. Asymptomatic cysts present a therapeutic dilemma: surgical intervention and "conservative" observation have advocates. The risk of malignancy in such cysts is considered by some an indication for surgical intervention and is reviewed in this paper. Pleuropulmonary blastoma (PPB) is the most frequent malignancy associated with childhood lung cysts. Although rare, PPB occurs predictably in certain clinical and familial situations. This unique biology of PPB can inform the cyst management decision. The earliest manifestation of PPB is a malignant lung cyst in young children, clinically and radiographically indistinguishable from benign congenital lung cysts. Histopathologic examination differentiates cystic PPB from the benign cystic variants. Surgical excision of cystic PPB (with or without chemotherapy) cures approximately 85-90% of children. If not excised, cystic PPB evolves to cystic/solid or solid high-grade sarcoma (cure rate 45-60%) by age 2-6 years. Numerous reports of "malignancy in a congenital lung cyst" are now understood as the characteristic progression of cystic PPB. PPB is genetically determined in many cases. Detailed family history may reveal the hallmarks of PPB in the patient or young relatives: a unique constellation of diseases including lung cysts, cystic nephroma, childhood cancers, stromal sex-chord ovarian tumors, seminomas or dysgerminomas, intestinal polyps, thyroid hyperplasias, and hamartomas. Pneumothorax and multifocal/bilateral lung cysts also characterize PPB. These diagnoses predict that a lung cyst is more likely PPB than a benign congenital cyst. Patients fitting this pattern deserve histologic diagnosis. The genetic basis for this heritable syndrome is unknown but is being actively investigated.

Pleuropulmonary blastema with cystic nephroma — A rare presentation and surgical dilemma

Pleuropulmonary balstema with cystic nephroma is a rare dual pathology of pediatric age group. The etiopathogenesis of this entity is not known, still researches indicate towards a common genetic cause. We report a case of this dual pathology in a one and half year old male. Till now only 5 cases have been reported.

Sonographic Diagnosis of an Unusual Case of Multilocular Cystic Nephroma Mimicking Polycystic Kidney Disease

The following is a report of the unusual case of a multilocular cystic nephroma in an 8-year-old boy who was transferred to our unit with a palpable abdominal tumor. The patient suffered from thoracic pain and night sweating. The laboratory values were normal. Abdominal sonography showed a huge kidney tumor on the right side consisting of numerous small cysts transversed by irregular septa of variable thickness. The cysts had a diameter of 1 -5 mm; larger cysts of more than 1 cm in diameter were not able to be shown. In the center of the tumor a normal renal parenchyma was able to be shown. The tumor arose like a mushroom from the kidney. Color Doppler sonography showed good vascularity of the normal renal parenchyma while the tumor had only a few internal vessels. The tumor was surgically removed. The histologic diagnosis was cystic nephroma. Unusual features of this tumor were the small size of the numerous cysts similar to polycystic kidney disease and the mushroom-like growth of the tumor.

Cystic nephroma and localized renal cystic disease in children: diagnostic clues and management

Background and Purpose Cystic nephroma (CN) and localized renal cystic disease (LRCD) are rare benign renal entities that can occur in children. A retrospective evaluation of the experience with these conditions was performed to emphasize the importance of differential diagnosis, recognition, and selection of the proper mode of treatment. Materials and Methods The medical records of patients treated for CN (n = 4) and LRCD (n = 1) between 1980 and 2007 were retrospectively evaluated. The age, sex, family history of renal cystic disease, presenting symptoms, physical examination findings, diagnostic radiologic imaging used, operative findings, details of the surgical procedure, histopathologic features, and outcomes were evaluated. Results There were 4 cases of CN and 1 case of LRCD without a positive family history. The age and sex of patients with CN were two 1-year-old girls and two 1.5-year-old boys. The patient with LRCD was a 4.5-year-old girl. The presenting symptoms were palpable mass in patients with CN and urinary tract infection in the patient with LRCD without impairment of renal function. Intravenous pyelography (n = 2), abdominal ultrasonography (n = 4), and computed tomography (n = 4) were used. All patients underwent an operation. Nephrectomy was performed in all 4 CN cases, and total excision of the cyst was performed in the LRCD case. Conclusion Pediatric surgeons should be familiar with the clinical, radiologic, surgical, and histopathologic characteristics of CN and LRCD. The presumptive diagnosis of CN prompts surgical intervention. Enucleation or partial nephrectomy is the treatment of choice in suitable cases. Nephrectomy should be reserved for CN, which totally replaces the parenchyma. Conservative treatment with follow-up imaging may be considered in selected cases of LRCD that have characteristic computed tomographic criteria. Operative intervention is indicated in symptomatic cases and should be limited to simple excision of the cysts.

Cystic nephroma: a case report and review of the literature

BackgroundThe spectrum of cystic renal neoplasms includes both benign and malignant tumors and the order is as follows: benign multilocular cyst, multilocular cystic renal cell cancer and cystic renal cell cancer. Gross similarities among multicystic tumors of the kidney may cause conflict in the diagnosis and treatment of these lesions.ResultsWe report a 53-year old male patient who presented with a mild persistent left flank pain and a painful left renal mass. After a series of examinations including abdominal ultrasound, intravenous pyelography and computed tomography, he underwent radical nephrectomy. Microscopic examination of the resected tissue showed the typical characteristics of a cystic nephroma. Immuno-histological staining of the epithelium of the tumour with CK 19 suggested an aberrant renal tubular differentiation.ConclusionCystic nephroma is a relatively rare benign lesion of the kidney. Since 1892, only 200 cases have been reported in the international literature. The non-specific clinical findings and the poor contribution of imaging examinations make the preoperative distinction from other cystic renal neoplasias difficult. Final diagnosis can be established in the histopathological examination of the completely rejected tumor in the pathology laboratory.

Comparison of Contrast-Enhanced Sonography with Unenhanced Sonography and Contrast-Enhanced CT in the Diagnosis of Malignancy in Complex Cystic Renal Masses

The objective of our study was to evaluate contrast-enhanced sonography in the diagnosis of malignancy in complex cystic renal masses. We analyzed a series of 40 cystic renal masses (diameter, 2-8 cm) with a complex pattern at contrast-enhanced CT in 40 consecutive subjects (18 men, 22 women; mean age +/- SD, 62 +/- 11 years). Each renal mass was scanned using sonography without contrast material and after IV injection of sulfur hexafluoride-filled microbubbles during the arterial (15-40 seconds) and venous (40-120 seconds from injection) phases. Two radiologists in consensus assessed onsite the enhancement patterns in the peripheral wall and intracystic septa and the evidence of solid endocystic components. Three blinded readers with 2, 6, and 10 years of experience in renal imaging performed a retrospective off-site interpretation of unenhanced sonography, contrast-enhanced sonography, and CT images and made a benign or malignant diagnosis according to refer ence diagnostic criteria for contrast-enhanced sonography and to the Bosniak classification for CT. Final diagnoses comprised two multilocular cystic nephromas, two inflammatory and seven hemorrhagic cysts, and eight uncomplicated benign cysts and 21 cystic renal cell carcinomas. The overall diagnostic accuracy of contrast-enhanced sonography was better than unenhanced sonography and CT (contrast-enhanced sonography vs unenhanced sonography vs CT: reader 1, 83% vs 30% vs 75%; reader 2, 83% vs 30% vs 63%; reader 3, 80% vs 30% vs 70%; p < 0.05, McNemar test). Contrast-enhanced sonography was found to be better than unenhanced sonography and CT in the diagnosis of malignancy in complex cystic renal masses.

Cystic nephroma and mixed epithelial stromal tumor of kidney: evolution of terminology, controversies, pathologic features and differential diagnosis

近年提出的肾上皮和间质肿瘤(renal epithelial andstromal tumor,REST)包括了囊性肾瘤(cystic nephroma)以及肾混合性上皮和间质肿瘤(mixed epithelial and stromatlllnor,MEST).囊性肾瘤和MEST之间在性别优势、年龄分布、上皮与间质成分的形态学和免疫组织化学表现方面均相似,但又在上述两种肿瘤的各自范畴内有所变异。

Les tumeurs du rein qui ne sont pas des carcinomes à cellules claires. État des lieux en 2008

Non clear cell renal cell carcinomas represent almost 20% of all renal neoplasms. Their classification is continuously being adjusted according to new cytogenetic and molecular data. Since molecular techniques are expensive, diagnosis still relies on morphological and immuno-histochemical criteria detailed hereby. Papillary renal cell carcinomas are the most important group and its classification is more and more complex. It encompasses low-grade papillary carcinomas (type 1 papillary renal cell carcinoma, oncocytic papillary renal cell carcinoma) and high-grade papillary carcinomas (type 2 papillary renal cell carcinoma, juvenile papillary carcinoma corresponding to renal carcinoma associated with Xp11.2 translocations and unclassified carcinomas). Mucinous tubular and spindle cell carcinoma and tubulocystic carcinoma are new entities, actually considered by some authors as low-grade papillary carcinomas. The so-called carcinoma of collecting ducts of Bellini and renal medullary carcinoma should be considered as intrarenal urothelial carcinoma or as high-grade papillary or unclassified carcinoma. Sarcomatoid carcinoma derives from morphological progression of any type of renal cell carcinoma. The group of oncocytomas/chromophobe renal cell carcinomas can be considered as a spectrum from benign (oncocytoma) to malignant neoplasm (chromophobe renal cell carcinoma). They are sometimes encountered in oncocytomatosis or familial Birt-Hogg-Dubbe syndrome in which tumoral cells may have hybrid features. Angiomyolipoma is usually a benign mesenchymatous neoplasm, that can be sporadic or familial (tuberous sclerosis). In the latter situation, some cases of epithelioid angiomyolipoma (potentially malignant) have been described. Renal epithelial and stromal tumors (REST) is a new concept gathering two benign mixed mesenchymal and epithelial tumors: cystic nephroma and mixed epithelial and stromal tumors (MEST).

Low grade epithelial stromal tumour of the seminal vesicle

BackgroundThe mixed epithelial stromal tumour is morphologically characterised by a mixture of solid and cystic areas consisting of a biphasic proliferation of glands admixed with solid areas of spindle cells with variable cellularity and growth patterns. In previous reports the seminal vesicle cystoadenoma was either considered a synonym of or misdiagnosed as mixed epithelial stromal tumour. The recent World Health Organisation Classification of Tumours considered the two lesions as two distinct neoplasms. This work is aimed to present the low-grade epithelial stromal tumour case and the review of the literature to the extent of establishing the true frequency of the neoplasm.Case presentationWe describe a low-grade epithelial stromal tumour of the seminal vesicle in a 50-year-old man. Computed tomography showed a 9 × 4.5 cm pelvic mass in the side of the seminal vesicle displacing the prostate and the urinary bladder. Magnetic resonance was able to define tissue planes between the lesion and the adjacent structures and provided useful information for an accurate conservative laparotomic surgical approach. The histology revealed biphasic proliferation of benign glands admixed with stromal cellularity, with focal atypia. After 26 months after the excision the patient is still alive with no evidence of disease.ConclusionCystoadenoma and mixed epithelial stromal tumour of seminal vesicle are two distinct pathological entities with different histological features and clinical outcome. Due to the unavailability of accurate prognostic parameters, the prediction of the potential biological evolution of mixed epithelial stromal tumour is still difficult. In our case magnetic resonance imaging was able to avoid an exploratory laparotomy and to establish an accurate conservative surgical treatment of the tumour.

Failure of Percutaneous Endoscopic Resection of a Renal Cystic Nephroma on Longer-Term Follow-Up

In 2005 we reported in this journal the treatment of cystic nephroma, a rare but presumed benign renal tumor, with percutaneous resection. Initial follow-up confirmed removal of the intra-pelvic portion of the cystic nephroma and persistence of the unresected intra-parenchymal portion. Surveillance with computed tomography revealed gradual regrowth of the mass, ultimately resulting in a size greater than that at the time of initial resection. Laparoscopic radical nephrectomy without adrenalectomy revealed benign cystic nephroma.

Adult cystic nephroma: A case report and a review of the literature

A 23-year old women who underwent radical nephrectomy due to right renal mass is presented. The histopathological examination is reported as adult cystic nephroma, a rare benign lesion of the kidney. The epidemiology, differential diagnosis, histopathological features, and treatment alternatives are discussed and the literature is reviewed.

Renal epithelial and stromal tumor: a new term to encompass the spectrum of cystic nephroma and mixed epithelial and stromal tumor of the kidney

Cystic nephroma (CN) and mixed epithelial and stromal tumor of the kidney (MEST) are rare benign cystic renal neoplasms, which have been the subject of considerable recent controversy. Within the past 2 years several studies have emphasized the overlapping clinical, morphologic and immunohistochemical features between these tumors, including their predominance in middle-aged to older women, a variably cystic architecture with flat to hobnail cells lining the cystic spaces and presence of ovarian-type stroma with occasional inhibin-positive luteinized cells. Thus, we have proposed the unifying term of ‘renal epithelial and stromal tumor’ (REST) to convey the idea that CN and MEST most likely represent ends of the spectrum of the same entity.

Adult Cystic Nephroma and Mixed Epithelial and Stromal Tumor of the Kidney: Clinical, Radiographic, and Pathologic Characteristics

Adult cystic nephroma (CN) and mixed epithelial and stromal tumor (MEST) are benign renal tumors readily distinguished from cystic renal cell carcinoma and other malignant variants based on histopathology. Clinical and radiographic data regarding these lesions are sparse, especially with respect to factors providing clinical suspicion for CN or MEST. Pathology of 22 CN (21 patients) and 10 MEST (9 patients) treated between 1987 and 2005 was re-reviewed according to 2004 WHO classification. Nineteen CN patients (90%) and 9 MEST patients (100%) were female and median ages were 55 (range: 39 to 79) and 52 (range: 39 to 67) years, respectively. Twenty-two patients (73%) presented symptomatically. CN were commonly Bosniak III lesions (77%), whereas 70% of MEST had solid enhancing components. An intrapelvic component was present in 5 CN (23%) and no MEST. Preoperative radiologic suspicion was documented in 36% of CN, but in only 1 patient with MEST. Nephron-sparing surgery was performed for 16 tumors (50%), including 5 suspected preoperatively and 3 that were 7 cm or greater. There was 1 case each of bilateral CN and MEST. Two patients with CN had concomitant renal cell carcinoma. One patient with MEST had sarcomatous component. At mean follow-up of 4.5 years (range: 1 to 18), no patient had novel or recurrent tumors develop. CN and MEST typically present symptomatically in perimenopausal women. Pedunculation of a multiloculated cystic lesion may allow for preoperative suspicion of these lesions in the proper clinical setting. Nephron-sparing surgery is the preferred treatment even for large and/or central lesions, if amenable.

Fat-Predominant Mixed Epithelial Stromal Tumor (MEST): Report of a Unique Case Mimicking Angiomyolipoma

A unique case of a mixed epithelial stromal tumor (MEST) that was predominantly composed of adipose tissue is reported here. Radiographically and grossly, the lesion was thought to be an angiomyolipoma, based upon its fatty appearance. Microscopically, the lesion was predominantly composed of mature adipose tissue but also contained clusters of bland tubules surrounded by smooth muscle bundles and collagen. By immunohistochemistry, the stroma labeled diffusely for estrogen and progesterone receptors, while the muscle bundles labeled for desmin. Melanocytic markers HMB45 and Melan A, typically positive in angiomyolipoma, were nonreactive. This case expands the morphologic spectrum of MEST to include mimics of angiomyolipoma.

Estrogen and progesterone-receptor-positive stroma as a non-tumorous proliferation in kidneys: a possible metaplastic response to obstruction

The presence of estrogen and progesterone-receptor-positive stroma is well known in renal mixed epithelial and stromal tumor, cystic nephroma, and angiomyolipoma with epithelial cysts. It has been suggested that the hormone receptor positivity in mixed epithelial and stromal tumor may be etiologically related to exogenous hormone intake—a phenomenon that has become more frequent in recent years. In the past few years, we have observed such stroma in some non-neoplastic kidneys, as well as in tumor-bearing kidneys away from the tumor. Herein we present our experience with 10 such cases. In a prospective manner, whenever we noted stroma resembling that in ovaries or müllerian organs (endometrial or cervical-like) in kidneys removed for any cause, immunohistochemical stains for estrogen and progesterone receptors were performed. There were eight males and two females among the group, with ages ranging from 11 months to 71 years. In six cases, the nephrectomies were performed for a non-functional kidney, and in three for tumors (one each of chromophobe, clear cell, and acquired cystic disease-associated renal cell carcinoma). One case was a partial nephrectomy for vesico-ureteric reflux, with upper pole hydronephrosis. Such stroma was present in nine cases as a non-mass forming proliferation around dilated, frequently inflamed pelvicalyceal system and collecting ducts. In one it was present at the periphery of an acquired cystic disease-associated renal cell carcinoma, as well as around non-tumorous cysts. The only common finding in all cases was a generalized or segmental hydronephrosis, or tumor compression-related focal obstruction. The stroma was positive for estrogen receptors in all 10 cases, and for progesterone receptors in seven. Thus, estrogen- and progesterone receptor-positive stroma can be present in the kidney, not only as a component of certain tumors, but also in association with non-neoplastic conditions. Its association with obstructive changes suggests that it may represent a metaplastic change in the renal interstitial cells surrounding these obstructed epithelial structures.

Lower Limits of Detection Using Magnetic Resonance Imaging for Solid Components in Cystic Renal Neoplasms

We determined the positive predictive value (PPV) for malignancy in complex renal cysts with focal nodular enhancement seen on magnetic resonance imaging (MRI). A surgical database was reviewed to identify all patients having both a preoperative 3 dimensional (3D) renal MRI and a radical or partial nephrectomy from January 2000 through April 2004 at our hospital. A group of 21 patients were identified with focal nodular enhancement within cystic renal masses. Pathologic correlation was made in each case. We performed 286 nephrectomies during the study period. Of these patients, 159 (56%) had a preoperative MRI studies. There were 21 of 159 (13%) patients with complex cystic lesions that displayed focal nodular enhancement, 14 of which (67%) measured 10 mm or larger in size. Twenty (95%) of the 21 lesions were renal cell carcinoma. The single, benign lesion was a cystic nephroma. Fuhrman grade 1 or grade 2 cancers were found in the majority of patients (80%), and there were no grade 4 cancers. Fifteen patients had a preoperative computerized tomography (CT) scan as well and nodular enhancement was suspected in only 4 patients (27%). MRI findings upgraded these lesions in 11 patients (73%). The demonstration of solid enhancing nodular components with high-resolution 3D MRI provides excellent positive predictive value for diagnosing neoplastic cystic renal lesions, including a large percentage 10 mm or larger in size. Our experience suggests a 95% likelihood that cystic renal lesions with focal nodular enhancement are malignant. We recommend that such lesions be considered malignant.

Multilocular cystic nephroma of the kidney

Multilocular cystic nephroma of the kidney

Bilateral mixed epithelial stromal tumor in an end-stage renal disease patient: the first case report

Although first intimated in the 1970s, mixed epithelial stromal tumor has been recognized as a diagnostic entity for less than 10 years, with an identity that has been challenged by overlap between other cystic renal neoplasms, most notably with cystic nephroma. We report the first case of a bilateral mixed epithelial stromal tumor occurring in a 41-year-old dialysis-dependent woman, notably also the first case reported in a patient with end-stage renal disease. The neoplasms occurred 5 years apart and were diagnosed as mixed epithelial stromal tumor in both instances. We describe the presentation and pertinent radiologic, histologic, and immunophenotypic findings of these neoplasms with a review of the current debate regarding mixed epithelial stromal tumor and cystic nephroma taxonomy.

Editorial Comment on: Cystic Nephroma and Mixed Epithelial and Stromal Tumour of the Kidney: Opposite Ends of the Spectrum of the Same Entity?

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Benign multilocular cyst or multilocular cystic nephroma in adults: three case reports

Multilocular cystic nephroma is an unusual entity of uncertain etiology that typically arises from the renal parenchyma. We report three such cases in adult females, in their fourth and fifth decades. Since existing imaging modalities cannot definitely exclude the possibility of multilocular cystic renal cell carcinoma these patients should undergo surgery.