Cytologic Features of Renal Carcinoma Associated with Xp11.2 Translocations/ TFE3 Gene Fusions: A Case Report with Voided and Catheterized Urine Cytology and a Literature Review

Cytomorphologic comparison of upper urinary tract urothelial carcinomas and renal cell carcinomas on urine cytology

INTRODUCTION

Compared to urothelial carcinomas (UCs), the cytomorphology of renal cell carcinomas (RCCs) is underdescribed. This study aims to investigate whether UCs and RCCS of the upper urinary tract can be differentiated cytologically, and to identify distinguishing cytomorphological features.

METHODOLOGY

Consecutive urine cytology specimens with atypical/C3, suspicious/C4 or malignant/C5 diagnoses matched with a nephrectomy or ureterectomy specimen with UC or RCC over a 15-year period were reviewed for cellularity, architecture, background composition and cytomorphologic features.

RESULTS

Totally 132 specimens were retrieved, comprising 24 RCCs and 108 UCs. Clear cell RCC (CCRCC) (n = 18) was the most common RCC. Urine cytology specimens from UC showed a trend of higher cellularity (p = 0.071) against RCC and was significant in subgroup analysis with CCRCC (p < .001). Epithelial structures in sheets, tubules, and papillae were exclusive in specimens of UC (p < .05). For background features, squamous cells were more common for RCC (p = .006) including CCRCC (p = .003), whereas polymorphs (p = .011) and necrotic material (p = .010) were associated with UC. Average nuclear size was larger and nuclear size variation (p < .001) and nuclear-cytoplasmic ratio (p = .001) were greater in UC (p = .001) than RCC. Comparing RCC to high-grade UCs only, nuclear-cytoplasmic ratio maintained statistical significance (p = .006) while average nuclear size showed a trend (p = .063).

CONCLUSION

A clean background free of tumor necrosis and polymorphs, and the lack of complex tumor fragments favors RCC. UCs also display larger nuclear size, higher nuclear size variation and nuclear-cytoplasmic ratio. These cytomorphological features with corroboration of clinical/radiological findings, can aid in raising a diagnosis of RCC.

TFE3-rearranged RCC with osseous metaplasia found on bone mass densitometry

Introduction and importance

Renal cell carcinoma (RCC) is the most common primary renal malignancy in patients between the ages of 50 and 70. A rare described variant of RCC is transcription factor for immunoglobulin heavy-chain enhancer 3 (TFE3) rearranged RCC. Osseous metaplasia, which refers to the occurrence of normal bone tissue in soft tissue, has been observed in all subtypes of renal cell carcinoma (RCC); however, only three previous case reports have documented the occurrence of osseous metaplasia in TFE3-rearranged RCC.

Case presentation

We present a case of a 65-year-old woman presenting with an incidentally discovered calcified Bi-lobed renal mass detected on bone densitometry composed of a calcified thick-walled cyst measuring 7×6.5×6.5 cm showing intraluminal densities and heterogeneous content, and a lobulated partially exophytic renal mass measuring 4.5×5.5×4.5 cm. The patient underwent robotic-assisted radical nephrectomy confirming the diagnosis of RCC with osseous metaplasia extending into the pelvic calyces and renal sinus fat implicating a pathological stage of T3a.

Clinical discussion

TFE3-rearranged RCCs represent a rare sub-classification in adult RCCs. It may be associated with unfavorable prognosis and aggressive patterns of disease in the presence of osseous metaplasia.

Conclusion

This is the first case in the literature of TFE3-rearranged RCC with osseous metaplasia on bone mass densitometry scan and the fourth case of TFE3-rearranged RCC with osseous metaplasia. The patient is to be treated as a high-risk patient and to be monitored closely for recurrence of malignancy, as indicated in the EAU guidelines.

Unravelling the mysteries of Xp11.2 translocation-associated renal cell carcinoma: A case report with a review of the literature

Cytomorphologic and immunocytochemical features of TFE3 translocation-associated renal cell carcinoma.

Cytological diagnosis of Xp11 translocation renal cell carcinoma: An unusual suspect in bone metastases from unknown primary malignancies

BACKGROUND

Renal cell carcinoma (RCC) constitutes 3% of all cancers, with a higher incidence in patients with age between 60 and 70 years. RCC frequently present as a metastatic tumor at diagnosis, and bones represent one of the most frequent sites. Many cases, mainly in young patients, includes the Xp11 translocation RCC. The cytological diagnosis of Xp11 translocation RCC in adult population it is rarely performed, likely for the morphological overlap with other adult renal cell carcinoma subtypes.

METHODS

We retrospectively analyze a series of 92 adult patients with metastatic bone tumors, diagnosed on fine-needle aspiration cytology (FNAC) samples, focusing mainly on the cytological, immunophenotypic and molecular features of Xp11 translocation RCC.

RESULTS

In our series 6 of 92 (6.5%) cases were metastatic RCC (mRCC), among them 2 cases were metastasis from Xp11translocation RCC. Those cases showed a bloody background, with several groups of atypical cells arranged in syncytial groups or in papillary groups composed by atypical cells with abundant cytoplasm, with scattered clear cells. TFE3 was positive on immunocytochemical analysis and specific translocation t(Xp11.23) was detected by FISH analysis.

CONCLUSIONS

In adult patients with mRCC, it is necessary to consider also Xp11 translocation RCC among the diagnostic hypotheses. FNAC represents a valid tool to investigate bone lesions but cytological features of Xp11 translocation RCC are still poorly described and must necessarily be better defined.

Cytopathology of Xp11 translocation renal cell carcinoma: a report of 5 cases

INTRODUCTION

Xp11.2 translocation-associated RCC (Xp11RCC) defined by molecular alterations involving TFE3 genetic rearrangements constitutes a large percentage of primary renal neoplasms in children, but less than 4% of adult cases. Fewer than 10 single case reports constitute the English cytopathology literature regarding this neoplasm. Our objective is to describe and illustrate the cytopathology of this uncommon renal neoplasm from a series of 5 cases using cytologic imprints, effusion specimens, and fine-needle aspiration (FNA) cytology.

MATERIALS AND METHODS

Review was made of our cytopathology and surgical pathology databases. FNA biopsy smears and imprint smears were performed using a standard technique. Effusion samples were processed using liquid-based slides.

RESULTS

Five cytologic specimens from 4 patients with histopathologically confirmed Xp11RCC were identified (mean age: 36 years) over a period of 7 years. All cases contained large cells with voluminous amounts of vacuolated cytoplasm arranged in non-descript clusters and as single forms. A "tigroid" pattern consisting of linear strips of detached cytoplasm was seen in both imprint smear cases and the single FNA case. Psammomatous calcifications, true papillary structures, and hyaline globules were absent in all cases. Four examples were diagnosed as Xp11RCC, but 3 represented metastatic disease, and 1 was diagnosed using both cytology and core needle tissue histopathology. The remaining case was diagnosed nonspecifically as a clear cell malignant neoplasm.

CONCLUSIONS

The cytopathologic features of Xp1RCC are relatively nonspecific, and overlap with other renal cell carcinoma subtypes. A definitive diagnosis is only possible with ancillary immunohistochemistry with or without additional TFE3 fluorescence in situ hybridization.

New entities, new technologies, new findings: A review of the cytologic features of recently established subtypes of renal cell carcinoma

Several new renal tumor types with distinctive pathologic, epidemiologic, and genetic signatures have recently been adopted in the fourth edition of the World Health Organization classification. In succeeding years, the cytologic features of most of these new types have been described, adding to the trend of increasing diagnostic accuracy for most common renal cell carcinoma subtypes and the important diagnostic role of cytologic sampling in the management and personalization of therapy. The current article reviews the cytologic findings from these recently established renal cell carcinoma subtypes. Emphasis is placed on cytologic diagnostic clues, confirmatory ancillary testing, salient differential diagnoses, and challenges that can be encountered in an attempt to render accurate interpretations in small samples.

Cyto-histological correlation of Xp11.2 translocation/TFE3 gene fusion associated renal cell carcinoma: Report of a case with review of literature

The MiT family translocation renal cell carcinomas (RCCs) are relatively rare in comparison to the conventional RCC. The cytologic features overlap with conventional clear cell RCC and papillary RCCs, thereby making the diagnosis extremely challenging. Here, we describe a case of TFE3 translocation associated RCC in a 58-year-old patient, with emphasis on cytomorphologic features and clues toward this diagnostic entity. Correlating the cytohistologic findings and review of touch imprints revealed that presence of hyaline nodules resembling leisegang rings and psammoma bodies in cytologic smears from kidney tumors serve as an important clue in raising a suspicion for the diagnosis of MiT family translocation RCCs.

Fine-needle aspiration findings of Xp11 translocation renal cell carcinoma metastatic to a hilar lymph node

Xp11 translocation renal cell carcinoma (RCC) is a specific type of renal cell carcinoma recently placed under the "MiT family translocation RCC" at the last 2013 ISUP Vancouver classification of renal neoplasia. This tumor contains variable proportions of clear cells and could easily mimic papillary RCC, clear cell type, and clear cell papillary RCC. Given the small number of published cytologic findings of this tumor, it could easily present as a diagnostic pitfall. We describe a case of a 23-year-old man with a history of prior nephrectomy who presented with multiple mediastinal lymphadenopathies on imaging surveillance follow-up. Fine-needle aspiration of the lymph node showed tumor cells with voluminous clear to eosinophilic cytoplasm, well-defined cell borders and hyperchromatic nuclei arranged in papillary architecture. Review of the prior nephrectomy specimen showed papillary cores surrounded by cells with voluminous clear to finely granular eosinophilic cytoplasm and distinct cell borders. Immunohistochemical stains performed on the nephrectomy specimen showed tumor positivity for CD10, E-cadherin, a-methylacyl coenzyme A racemase, and TFE3 supporting the diagnosis of Xp11 translocation renal cell carcinoma. Although this tumor was initially described predominantly in children, it could also occur in adults, as seen in this case. Familiarity with the cytologic findings of this tumor, use of immunohistochemical stains, or cytogenetic test to determine the type of gene fusion will be extremely useful in arriving at the correct diagnosis. Diagn. Cytopathol. 2017;45:456-462. © 2017 Wiley Periodicals, Inc.