Papillary renal cell carcinoma embedded in an oncocytoma: Case report of a rare combined tumour of the kidney

Oncocytoma with a vascular extension, associated with a papillary carcinoma: A case report

This is a case report about a patient which presents with two right renal tumors, one of them being an oncocytoma with typical histopathological features and renal vein extension. Recent studies show that despite renal vein thrombus being a histological sign of malignancy; when associated with renal oncocytoma, it should not alter the benign prognosis of oncocytoma, and a simple follow-up may be carried. Further explorations should be done when easily available, and when the histopathologic diagnosis of oncocytoma is uncertain, to rule out the differential diagnosis of a chromophobe renal cell carcinoma, oncocytic variant.

Acute pyelonephritis revealing a rare renal collision tumor of papillary and chromophobe cell carcinoma with sarcomatoid features

A 59-year-old male patient was admitted to the emergency room with febrile right flank pain. The computed tomography scan and the magnetic resonance imaging had objectified lesion image occupying the upper half of the right kidney, measuring 82 mm, suggesting an infectious origin without excluding the infected tumor. He was put under antibiotics. A percutaneous biopsy revealed renal cell carcinoma with suppurative tumor necrosis. He underwent a right radical nephrectomy. The histopathological study revealed a collision tumor of papillary, chromophobe renal cell carcinoma and sarcomatoid dedifferentiation. It is the second case reported in English literature to date.

Collision kidney tumor with clear cell renal cell carcinoma and papillary type 1 renal cell carcinoma. A case report and review of the literature

INTRODUCTION

The most common renal neoplasms include clear cell, papillary, and chromophobe renal cell carcinomas. The simultaneous occurrence of different histological types of adjacent neoplasms in the same organ is known as a collision tumor. Collision kidney tumors have already been described but only in rare cases.

CASE DESCRIPTION

In this case report we present a 68-year-old man with chronic kidney insufficiency under dialysis who underwent an open right nephrectomy in our department with the histological diagnosis of a collision kidney tumor consisting of clear cell and papillary type 1 renal cell carcinoma.

CONCLUSION

To the best of our knowledge, our case of a collision kidney tumor consisting of clear cell RCC and papillary type 1 RCC, is unique in literature.

Collision tumors of the lung: A case report of urothelial carcinoma metastasizing to renal cell carcinoma with heterotopic ossification

Collision tumors are rare entities that consist of at least two or more histologically and ontologically distinct tumor types within the same organ. It is still not well understood how collision tumors form; yet, three main theories have been proposed to explain the pathogenesis, including the “random collision effect,” “field cancerization,” and “tumor-to-tumor carcinogenesis.” Collision tumors have been encountered in various body organs, including the lung. They either consist of a metastasizing tumor colliding with primary cancer or distinct primary or metastatic cancers colliding together. Here, we describe a rare case of collision tumors of the lung that consists of two metastatic carcinomas, namely renal cell carcinoma and urothelial carcinoma of the bladder. We propose that the urothelial carcinoma disseminated into several pre-existing pulmonary metastases of renal cell carcinoma with heterotopic bone formation. The possible mechanisms underlying the development of this peculiar tumor are discussed.

Open partial nephrectomy for a collision renal cell carcinoma in a transplant kidney: A case report

A collision tumour of the kidney is a very rare condition defined by two immediately adjacent but histologically distinct neoplasms that coexist within one organ without histological admixture. We present a collision tumour in a transplant kidney treated with open partial nephrectomy. This case also highlights key surgical principles the enhanced risk of oncogenesis in transplant recipients, and some key principles for surgical resection of a tumour in a transplant kidney.

Case report of a combined oncocytoma and type 1 papillary renal cell carcinoma: a rare entity

An extremely rare renal hybrid tumor composed of papillary renal cell carcinoma (PRCC) and renal oncocytoma (RO) within the same tumor is described. Only eight previous cases are documented in the literature. A 44-year-old man showed a 3.5 cm renal mass composed by areas with tubulo-papillary structures made up with small cells with scanty cytoplasm adjacent to polygonal cells forming solid sheet and tubules with abundant eosinophilic cytoplasm and uniform, round central nuclei without mitoses. Complete immunohistochemical panel suggested a diagnosis of type 1 PRCC combined with RO. Contrary to previous cases of hybrid renal tumors reported in the literature, no pseudocapsule divided the two histotypes of tumors. Our patient is the youngest among the previous reports being 44. Collision tumours have previously been described, although mixed renal tumours composed of oncocytoma and PRCC is extremely rare. There is no evidence to suggest a relationship between oncocytoma and papillary RCC since they originate from different cells and have different prognoses. Given the possibility of oncocytomas to harbour other tumours, we suggest careful examination of the samples to exclude the presence of an associated malignant neoplasm, which might have a significantly worse prognosis than oncocytoma. Differential diagnosis is needed, and immunohistochemical stains are of great help in distinguishing between the two histological components.

A back-to-back tumor composed of papillary renal cell carcinoma and oncocytoma treated by laparoscopic partial nephrectomy: a case report

Background

Renal oncocytoma is the most common benign renal tumor, and papillary renal cell carcinoma is the second most common histologic subtype of renal cell carcinoma. Renal tumors containing different components such as papillary renal cell carcinoma and oncocytoma are extremely rare.

Case presentation

A renal mass was incidentally detected in a 52-year-old Korean woman, and a computed tomographic scan showed a 32-mm multicystic mass with some calcifications in the lower pole of the right kidney. She underwent laparoscopic partial nephrectomy without any perioperative complications. We found a papillary renal cell carcinoma and an oncocytoma in a tumor mass.

Conclusions

The possibility of a mixed malignant tumor should be considered while treating benign tumors such as oncocytoma.

Primary collision tumors of the kidney composed of oncocytoma and papillary renal cell carcinoma: A review

BACKGROUND

There are well known cases of hybrid tumors of chromophobe renal cell carcinoma (RCC) and oncocytoma in kidney, where both tumors have the same cell of origin - intercalated cell of the collecting duct. However, collision tumors composed of neoplasms originating from different cell lineages such as oncocytoma and papillary RCC are extremely rare. Herein, we made a collective literature review of reported cases of collision tumors composed of oncocytoma and papillary RCC, adding a case that we recently experienced.

MATERIAL AND METHODS

A PubMed database was search for collision tumors of the kidney composed of oncocytoma and papillary RCC and a collective literature review was made. To this cohort, we also added a recently encountered case with similar, confirmed by immunohistochemistry, morphological features.

RESULTS

To date 8 cases of a collision tumor composed of papillary RCC and oncocytoma have been described in the literature. All of them had a smaller papillary RCC component present within a larger oncocytoma.

CONCLUSION

Because of a few cases of such a collision tumors reported, it is difficult to make classification and right clinical management of these patients. None of the reported cases had tumor recurrence or progression on a follow-up. The presence of only small portion of papillary RCC in a large oncocytoma raises a possibility of under-sampling of malignant component in large oncocytomas in core biopsy or surgically resected specimens. We recommend better sampling, particularly at the periphery of otherwise classic oncocytomas to unveil this possible association.

Primary collision renal tumor of papillary renal cell carcinoma within an oncocytoma: emergency presentation of a rare entity

BACKGROUND

The coexistence of an oncocytoma and a papillary renal cell carcinoma (PRCC) in the same neoplastic mass constitute a collision tumor and is an extremely rare entity. Until now, only six incidentally diagnosed cases have been reported, concerning patients older than 65 years.

CASE REPORT

A 57-year-old man was admitted to the Emergency Department with acute pain and anemia, due to renal hematoma following rupture of such a neoplastic collision mass. The patient underwent an emergency nephrectomy, which revealed a 10.6 cm oncocytoma and a 1.3 cm PRCC. He had an uncomplicated postoperative recovery and remained healthy at the 65-month follow-up, the longest of all previous cases.

CONCLUSION

While prognosis appears favorable, the current report shows that these collision tumors may cause emergency and dangerous medical conditions that deserve prompt treatment. HIPPOKRATIA 2017, 21(2): 105-107.

A collision tumor of papillary renal cell carcinoma and oncocytoma: case report and literature review

OBJECTIVES

The most common renal neoplasms include clear cell, chromophobe, and papillary renal cell carcinomas (PRCCs) and oncocytomas. While lesions containing hybrid features of different tumor types, such as hybrid oncocytic tumors, have been well documented in the literature, the finding of a collision tumor of two distinct tumor types- PRCC and oncocytoma-is extremely rare.

METHODS

We present a case of PRCC associated with an oncocytoma. Our discussion includes a review of the available literature on this rare type of collision tumor.

RESULTS

Prosection of a partial nephrectomy performed in a 78-year-old man for painless gross hematuria and nocturia revealed a 6.4 × 5 × 3.6-cm well-delineated orange to yellow-tan mass harboring a white-tan 1 × 0.9 × 0.9-cm mass. Histologic diagnosis of PRCC associated with an oncocytoma was rendered. By immunohistochemistry, focal CK7 expression was present in the oncocytoma, while strong diffuse positive CK7 expression was present in the PRCC component. Fluorescence in situ hybridization (FISH) revealed trisomy 17 in 39.3% of PRCC tumor nuclei but no significant chromosomal aberration in oncocytoma.

CONCLUSIONS

In view of this and previously reported cases, thorough sectioning and examination, especially in large oncocytomas, is recommended to exclude the presence of an associated malignancy. To our knowledge, trisomy 17 by FISH has not been previously reported in these extremely rare tumors.

Papillary renal cell carcinoma within a renal oncocytoma: Case report of very rare coexistence

Renal oncocytomas accounts for 3% to 9% of primary renal neoplasms. The coexistence of renal cell carcinoma (RCC) within the oncocytoma is extremely rare. We report the case of an asyptomatic 74-year-old man with papillary RCC within oncocytoma managed with left radical nephrectomy.

Renal collision tumour of papillary cell carcinoma and chromophobe cell carcinoma with sarcomatoid transformation: A case report and review of the literature

The simultaneous occurrence of different histological types of adjacent neoplasms in the same organ is called a collision tumour, and rarely occurs in the kidney. A 63-year-old female presented to the urology department with a 1-month history of a painless hematuria. The computed tomography scans of the abdomen revealed 2 heterogeneous incidental right renal masses. The patient underwent radical nephrectomy including lymphadenectomy without adjuvant therapy. Histopathological examination showed a type 2 renal collision tumour of the papillary renal cell carcinoma with eosinophilic cytoplasm and pseudostratified nuclei on papillary cores, and chromophobe renal cell carcinoma characterized by large polygonal cells with transparent reticulated cytoplasm and prominent cell membranes, which exhibited sarcomatoid transformation in the local area. Routine follow-up demonstrated no local or distant metastasis signs of recurrence at 20 months.