A contemporary update on hyalinizing clear cell carcinoma: compilation of all in-house cases at our institution and a literature review spanning 2015-2020

Pulmonary salivary gland tumor-hyalinizing clear cell carcinoma: a literature review

Primary pulmonary hyalinizing clear cell carcinoma (HCCC) is a very rare lung tumor that accounts for less than 0.09% of all primary lung tumors and has no specific epidemiology. The correct diagnosis requires imaging, laboratory, pathological, immunohistochemical, and molecular examination. The most typical feature of pulmonary HCCC is the clear cell component with clear stroma. In addition, the fusion gene EWSR1::ATF1 due to t(12;22)(q13;q12) is essential for the pathological diagnosis of pulmonary HCCC. The main treatment for pulmonary HCCC is surgery. This review focus on the pathological features, immunohistochemical examination, mutation analysis and treatment of pulmonary HCCC.

Carcinomas with clear cell features and EWSR1 rearrangements: a report of 3 cases

Salivary gland and odontogenic neoplasms with extensive clear cell change are rare lesions but have been increasingly characterized over the past decade. Among this heterogeneous group of neoplasms, hyalinizing clear cell carcinoma (HCCC), clear cell odontogenic carcinoma (CCOC), and clear cell myoepithelial carcinoma (CCMC) share a monophasic clear cell morphology and an EWSR1 gene rearrangement. While HCCC is relatively well characterized, there are a limited number of EWSR1-reaarranged CCMC of salivary glands reported, and its clinicopathologic features in relation to HCCC and nonclear cell myoepithelial carcinoma (MC) have not been clarified. This report describes the clinical, morphologic, and immunophenotypic features of 3 carcinomas composed predominantly of clear cells and with EWSR1 rearrangements by fluorescence in situ hybridization. A comparative literature analysis suggests that HCCC, CCMC, and nonclear cell MC of salivary glands are clinically, histopathologically, and molecularly distinct.

Primary pulmonary hyalinizing clear cell carcinoma with vocal-cord squamous cell carcinoma: a case report with systematic review

BACKGROUND

Primary pulmonary hyalinizing clear cell carcinoma (HCCC) is a low-grade salivary gland-type carcinoma. Until now, 23 cases of pulmonary HCCC have been reported.

CASE PRESENTATION

Here, we present a patient with primary pulmonary HCCC along with vocal-cord squamous cell carcinoma (SCC) revealed by biopsy examination. The patient underwent radiotherapy for vocal-cord SCC, followed by right upper lobectomy and lymph node dissection 10 months later. Histology revealed polygonal cells with eosinophilic or clear cytoplasm in the myxoid matrix together with hyaline degeneration. The tumor involved the whole layer of the segmental bronchus and regionally involved the alveolar tissue along with one intrapulmonary lymph node. Targeted RNA sequencing revealed Ewing Sarcoma Breakpoint Region 1 (EWSR1)- activating transcription factor 1 (ATF1) fusion. We analyzed the data on pulmonary malignant tumors between 2000 and 2019 in the Surveillance, Epidemiology, and End Results (SEER) database and reviewed all cases of pulmonary HCCC with EWSR1 fusion by searching PubMed. The results showed that head and neck (HN) adenoid cystic carcinoma (ACC) (47.89%) and HNSCC (22.54%) were the most common carcinomas occurring with pulmonary salivary gland-type malignant tumors. Screening of 24 cases of pulmonary HCCC with EWSR1 fusion revealed that five cases demonstrated lymph node metastases and only two had documented tumor recurrences. HCCC is rare and easily misdiagnosed as SCC, but the treatment regimen differs between pulmonary HCCC and SCC.

CONCLUSIONS

Hence, pulmonary tumors with clear cells must be diagnosed with caution. Next-generation sequencing (NGS) may be useful for diagnosis, especially in cases with a history of squamous cell carcinoma (SCC).

Primary pulmonary hyalinizing clear cell carcinoma with fusions of both EWSR1::CREM and IRF2::NTRK3: report of a case with an aggressive behavior

Primary pulmonary hyalinizing clear cell carcinoma (HCCC) is a rare salivary gland-type tumor newly recognized in recent years, with approximately 21 cases reported to date in the English literature, which constitutes a challenge in pathology diagnosis, particularly in small biopsy specimens. Here, we present a case of pulmonary HCCC diagnosed by computed tomography-guided percutaneous lung biopsy in a 70-year-old man's right lower lung. Although the morphology and immunophenotype of the tumor suggested the diagnosis of mucoepidermoid carcinoma, fluorescence in situ hybridization failed to reveal the rearrangement of MAML2 gene, which is characteristic of mucoepidermoid carcinoma. Instead, further molecular genetic testing showed that the tumor harbored a rare EWSR1::CREM fusion combined with a previously unreported IRF2::NTRK3 fusion. Pulmonary HCCC is commonly regarded as a low-grade malignant tumor with an indolent course, but this case has a different biological behavior, presenting extensive dissemination and metastases at the time of diagnosis, which expands our understanding of the prognosis of this tumor. The patient has had five cycles of combination chemotherapy and has been alive with the tumor for eight months.

Primary pulmonary hyalinizing clear cell carcinoma with pseudopapillary structures and abundant cysts filled with mucus

Pulmonary hyalinizing clear cell carcinoma (HCCC) is a new and rare form of lung salivary gland tumor. Only twenty-two cases have been reported in the literature to date. Furthermore, their clinicopathological features have not been fully characterized. In this paper, we describe the clinicopathological characteristics, immunohistochemical features, and molecular genetic changes in two HCCC cases. We also simultaneously reviewed related literature on similar cases reported. Of the two cases, one was of a 58-year-old man with a 4.3 cm lung tumor, which was the largest among all previously reported cases. The tumor showed an infiltrative growth pattern and perineural and vascular invasion microscopically. Moreover, nuclear grooves, high mitotic figures, and comedo necrosis were observed in addition to classic morphological features. More importantly, rare pseudopapillary structures were observed. The second case was of a 60-year-old woman in whom the tumor was mainly composed of multiple cysts filled with mucus. The remaining focal solid areas of the tumor comprised clear and acidophilic cells embedded in the hyalinizing stroma. Immunohistochemical analysis revealed that the tumor cells of both cases were positive for CK5/6, p40, and p63 expression, but negative for napsin A, TTF-1, and SOX10 expression. The HCCC diagnosis in both cases was validated by fluorescence in-situ hybridization (FISH) examination, which showed Ewing sarcoma breakpoint region 1-activating transcription factor 1 (EWSR1-ATF1) gene fusion. Primary pulmonary HCCC is a rare lung tumor originating from the bronchial mucosa, and its histological features may vary, such as rare pseudopapillary structures and abundant cysts. Thus, the diagnosis should be a combined analysis of histopathological characteristics with immunophenotype and molecular examination, including EWSR1-ATF1 gene fusion detection.

Screening of Differentially Expressed Iron Death-Related Genes and the Construction of Prognosis Model in Patients with Renal Clear Cell Carcinoma

Objective

In this study, we used the TCGA database and ICGC database to establish a prognostic model of iron death associated with renal cell carcinoma, which can provide predictive value for the identification of iron death-related genes and clinical treatment of renal clear cell carcinoma.

Methods

The gene expression profiles and clinical data of renal clear cell carcinoma and normal tissues were obtained in the TCGA database and ICGC database, and the differential genes related to iron death were screened out. The differential genes were screened out by single and multifactor Cox risk regression model. R software, "edge" package (version 4.0), was used to identify the DELs of 551 transcriptional gene samples and 522 clinical samples. The risk prediction model with genes was established to analyze the correlation between the genes in the established model and clinical characteristics, Through the final screening of iron death related genes, it can be used to predict the prognosis of renal clear cell carcinoma and provide advice for clinical targeted therapy.

Results

Seven iron death differential genes (CLS2, FANCD2, PHKG2, ACSL3, ATP5MC3, CISD1, PEBP1) associated with renal clear cell carcinoma were finally screened and were refer to previous relevant studies. These genes are closely related to iron death and have great value for the prognosis of renal clear cell carcinoma.

Conclusion

Seven iron death genes can accurately predict the survival of patients with renal clear cell carcinoma.

Primary lung hyalinizing clear cell carcinoma: a diagnostic challenge in biopsy

Introduction

Hyalinizing clear cell carcinomas (HCCCs) are rare, low-grade, malignant tumors. They most commonly involve the minor salivary glands of the head and neck. HCCC that occurs in uncommon locations and examining samples from small biopsy pose a diagnostic challenge for most pathologists.

Case presentation

We herein report a primary pulmonary HCCC diagnosed by small biopsy and summarize its histologic, immunophenotypic, and molecular features along with a review of 11 previously reported cases to emphasize the potential diagnostic pitfalls.

Conclusions

Small biopsy diagnosis of primary pulmonary HCCC is challenging. A collection of mimics needed to be ruled out. Awareness of the key morphologic features of pulmonary HCCC combined with essential immunohistochemistry and molecular tests contributes to the correct diagnosis.

Clinicopathological and molecular study of 10 salivary gland clear cell carcinomas, with emphasis on rare cases with high grade transformation and occurring in uncommon sites

Background

As a rare salivary gland malignancy, clear cell carcinoma (CCC) is easily misdiagnosed. This study identified the features that allow better recognition of the clinicopathological and molecular characteristics and the prognosis of CCC, focusing on high-grade transformation (HGT) in this tumor and cases arising in uncommon sites.

Methods

Clinicopathological and follow-up data for 10 CCC samples were retrieved. Immunohistochemical (IHC) staining was performed, and fluorescence in situ hybridization (FISH) was used to detect EWSR1 gene rearrangements, EWSR1–ATF1 gene fusions, and MAML2 gene rearrangements.

Results

Histologically, typical CCCs comprised bland polygonal or round cells with clear cytoplasm. In contrast with typical CCCs, HGT tumor cells exhibited nuclear pleomorphism, high nuclear-to-cytoplasmic ratios, high mitotic activity, and necrosis. Rare morphologic features such as pseudopapillae, gland-like spaces, and entrapped ducts were also observed. Occasionally, tumors involving the oral cavity might arise from the overlying epithelium of the mucosal surface. Immunohistochemically, all the cases expressed p63, p40, and CK5/6, while myoepithelial-related markers were uniformly negative in all cases. HGT exhibited a wild type p53 expression pattern. FISH demonstrated EWSR1 rearrangement (10/10) and EWSR1–ATF1 fusion (4/5); however, MAML2 remained intact (0/3).

Conclusions

CCCs with HGT or occurring in uncommon sites are extremely rare. Combining morphology based IHC and molecular detection provided reliable evidence that the HGT component represented a transformation of CCC rather than the coexistence of another tumor and helped differentiating CCCs in uncommon sites from their mimics, avoiding potential misdiagnosis and inappropriate therapy. The overall prognosis for CCCs is good, except for the HGT cases, which needed continued treatment.