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

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.

Melanotic Xp11-associated tumor of the sigmoid colon: A case report

BACKGROUND

Melanotic Xp11-associated tumors are rare mesenchymal-derived tumors. So far, most primary melanotic Xp11-associated tumors have been reported in the kidney, and reports of this tumor in the gastrointestinal tract are rare.

CASE SUMMARY

Here we describe the case of a 25-year-old woman who presented with a melanotic Xp11-associated tumor in the sigmoid colon. Colonoscopy revealed a large mucosal bulge in the sigmoid colon, approximately 32 cm inside the anus. The surface was rough with local erosion. The tumor was brittle on biopsy and bled easily. Computed tomography revealed thickening of the rectal wall with edema. Postoperative pathology indicated the likelihood of a perivascular epithelioid cell tumor. Histologically, the tumor comprised plump epithelioid cells with abundant clear to lightly eosinophilic cytoplasm and round nuclei arranged in an alveolar or trabecular pattern. The tumor cells were strongly positive for HMB-45, Melan-A, Cathepsin K, and TFE3 but negative for vimentin, smooth muscle actin, S100 protein, CD10, CK20, and desmin. The tumor cells had a low Ki-67 labeling index (approximately 2%). Fluorescence in situ hybridization revealed TFE3 fracture. Based on these histologic and immunohistochemical features, a diagnosis of melanotic Xp11-associated tumor of the sigmoid colon was made.

CONCLUSION

In summary, we report the clinicopathological features of a primary tumor that is extremely rare in the sigmoid colon and review the clinicopathological characteristics of melanotic Xp11-associated tumors, compatible with the very rare tumor termed “melanotic Xp11 translocation renal cancer” in all aspects.

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.