The rhabdoid variant of adrenocortical carcinoma-Report of three cases and literature review

Adrenocortical carcinoma (ACC) is a rare and aggressive malignancy. Extensive rhabdoid morphology in ACC has been described recently in very few cases. The proportion of rhabdoid morphology and the role of SMARCB1/ INI1 expression in these tumor cells to diagnose the specific variant is not described in the literature. We reviewed the clinicopathological features of nine cases of adrenocortical neoplasm. Out of which, three cases of ACC showed predominant rhabdoid morphology. Large discohesive cells with abundant cytoplasm containing eosinophilic inclusions, eccentric vesicular nucleus, and prominent nucleoli. INI1 immunostain was retained in all cases. We reported the rhabdoid variant of ACC, a novel entity, and its diagnostic approach from their histological mimickers. Identifying more cases of this entity will help to clearly understand the pathogenesis, biologic behaviour, and any specific molecular alterations in the future.

SMARCB1 (INI-1) – Deficient sinonasal carcinoma: Report of two cases

SMARCB1 (INI-1)-deficient sinonasal carcinoma is a rare, poorly differentiated carcinoma defined by complete loss of tumor suppressor gene SMARCB1 (INI-1) within the neoplastic cell nuclei demonstrated by the immunohistochemical stain. SMARCB1 (INI-1) gene inactivation has been implicated in the pathogenesis of a diverse group of malignant neoplasms that tend to share “rhabdoid” morphology. SMARCB1 (INI-1)-deficient sinonasal carcinoma was first reported by Agaimy et al. in 2014. These tumors are often basaloid with focal rhabdoid differentiation, prominent necrosis, increased mitotic activity, and aggressive behavior. Other than being INI-1 and NUT negative, they are positive for pancytokeratin and express variable immunoreactivity for squamous markers like p63 and neuroendocrine markers like synaptophysin. Most patients present with locally advanced disease and hence a combination of chemotherapy, radiotherapy, and surgery is usually recommended.

SMARCB1 deficient sinonasal carcinoma: An emerging entity with a diagnostic challenge

SMARCB1 deficient sinonasal carcinomas are rare neoplasms, classified under sinonasal undifferentiated carcinomas by the fourth edition of the World Health Organization (WHO) classification of head and neck tumors. It is characterized immunohistochemically by loss of SMARCB1(INI1) expression. We are reporting the case of a 63-year-old man who was evaluated for nasal stuffiness of 3 months duration in another hospital where a radiological evaluation showed a polypoidal soft tissue lesion in the right maxillary sinus extending to the right nasal cavity and spheno-ethmoidal sinus. He underwent excision biopsy which was reported as non- keratinizing nasopharyngeal carcinoma. He was referred to our center with residual disease in spheno-ethmoidal recess for which radiotherapy was given. After completion of radiotherapy, the primary site had no residual disease, but while on follow-up he developed left sided neck nodes within 4 months of completion of treatment. Excision of the lesion was done and histopathological and immunohistochemical analysis revealed it to be metastasis from SMARCB1 deficient sinonasal carcinoma and not nasopharyngeal carcinoma as diagnosed from the other center. This case is being reported to highlight the diagnostic challenge associated with this rare entity.

Clinical and imaging features of the SMARCB1-de?cient sinonasal carcinoma / 中华放射学杂志

Objective:To assess the clinical and imaging features of SMARCB1-deficient sinonasal carcinoma.Methods:Form January 2016 to November 2021, the clinical data and pretreatment imaging findings of 16 cases with pathologically proven SMARCB1-de?cient sinonasal carcinomas were analyzed retrospectively in Beijing Tongren Hospital, Capital Medical University. Immunohistochemistry for SMARCB1 showed loss of the protein in the tumor nuclie. Clinical and imaging features, including tumor location, TNM stage, size, density of CT, bone change, MRI signal intensity, enhancement pattern, type of time-intensity curve (TIC) of dynamic contrast enhanced MRI (DCE-MRI), apparent diffusion coefficient (ADC) value and diffusion weighted imaging (DWI) were evaluated. For 14 cases, correlation of the ADC value and Ki-67 index was subsequently evaluated with Pearson correlation analysis.Results:For the 16 cases SMARCB1-deficient sinonasal carcinomas, clinical stage of T4 was 12 cases and T3 was 4 cases. The location included ethmoid sinus ( n=4), nasal cavity only ( n=1), both nasal cavity and ethmoid ( n=8), ethmoid and maxillary sinus ( n=1), ethmoid and frontal sinus ( n=1), ethmoid and sphenoid sinus ( n=1). The tumor size was (4.5±1.2) cm. Iso-attenuated of CT images was showed in 13 cases and heterogeneous with necrosis was showed in 3 cases. Focal bone erosion was found in 13 cases and extensive bone destruction was found in 3 cases. Compared with adjacent muscles, T 1WI of all 16 cases showed isointense, with focal hypointense in 3 cases. On T 2WI, the tumor was graded as isointense in 9 cases, hyperintense in 7 cases, with lower inner septal in 6 cases. Enhancement was graded as mild in 11 cases, moderate in 5 cases.MRI Enhancement images showed mild enhancement in 11 cases, moderate enhancement in 5 cases, heterogeneous enhancement in 6 cases, and homogeneous enhancement in 10 cases. For DCE-MRI of 14 cases, there were 10 cases of Ⅲ type and 4 cases of Ⅱ type of the TIC. The ADC value of 14 cases was (1.02±0.27)×10 -3 mm 2/s. The Ki-67 index was 48%±21%. No correlation was observed between Ki-67 index and ADC value ( r=-0.38, P=0.183). Conclusions:SMARCB1-deficient carcinomas are mostly centered in the nasal and ethmoid region of anatomic distribution. Tendency to be infiltrative the adjacent bone structure with invasive bone reaction, mild to moderate heterogeneous enhancement, T 2WI with lower inner septal, and Ⅲ types of TIC are certain suggestive imaging features of the entity.

Presacral schwannoma: a bizarre presentation in the Pandora’s box of abdomen and pelvis

Schwannomas are benign tumors arising from the Schwann cells of nerve fibers. They are extremely rare in the pelvis accounting for only 1-3% of all schwannomas. These tumors are nonaggressive, slow growing, solitary neoplasms with an extremely low possibility of malignant transformation or recurrence after excision. We present a case of a 19 years old male with complaints of radiating pain from lower back to the left thigh associated with altered bowel and bladder habits. Following a detailed work up he underwent laparotomy and mass excision. Histopathological report revealed presacral schwannoma. Post-surgery patient improved symptomatically and is on regular follow up. There are a smaller number of cases of presacral schwannoma reported in the literature. Due to its outlandish striking presentation, diagnosis is very challenging. Although presacral schwannoma is rare, it should be considered as a differential diagnosis in the back of the mind of a surgeon while dealing a case of pelvic mass. In symptomatic and asymptomatic cases, surgical excision is the mainstay of treatment of these tumors.

Comparison between Fluorescence in-situ Hybridization (FISH), Reverse Transcriptase PCR (RT-PCR) and fragment analysis, for detection of t (X; 18) (p11; q11) translocation in synovial sarcomas

Background: Synovial sarcoma (SS) is an aggressive, but a relatively chemosensitive soft tissue sarcoma, characterized by a specific, t (X;18)(p11;q11) translocation, leading to formation of SS18–SSX chimeric transcript. This translocation can be detected by various techniques, such as fluorescence in-situ hybridization (FISH), reverse transcriptase PCR (RT-PCR) and fragment analysis. Objectives: To compare the results of detection of t (X;18)(p11;q11) translocation, across three different platforms, in order to determine the most optimal and sensitive technique. Methods: Formalin-fixed paraffin embedded (FFPE) tissue sections of 45 soft tissue sarcomas were analyzed, including 16 cases of SS confirmed by histopathology, immunohistochemistry and molecular technique (s)(Group 1); 13 cases, wherein SS was one of the differential diagnosis, preceding molecular testing (Group 2) and 16 cases of various other sarcomas (Group 3). Various immunohistochemical (IHC) markers studied, including INI1/SMARCB1. All cases were tested for t (X;18) translocation, by fragment Analysis, FISH and RT-PCR. Results: There were 23 cases of SS, including 16 of group 1 and 7 of group 2. By fragment analysis, t (X;18)(p11;q11) translocation was detected in 22/23 cases (95.6%). By FISH, SS18 gene rearrangement was detected in 18/22 cases (78.2%), whereas by RT-PCR, SS18-SSX transcripts were detected in 15/23 cases (65.2%). Immunohistochemically, a unique “weak to absent”/reduced INI1 immunostaining pattern was exclusively observed in 12/13 cases of SS (92.3%). Fragment analysis and FISH were relatively more sensitive techniques. Unique “weak to absent”INI1 immunoexpression significantly correlated with positive t (X;18) translocation results (P = 0.0001). Conclusion: The present study constitutes first such study from our subcontinent. Fragment analysis is a promising technique for detection of t (X;18)(p11;q11) translocation. FISH and INI1 immunostaining pattern were also relatively more sensitive, over RT-PCR.

Metastatic poorly differentiated chordoma: the eyes do not see what the mind does not know

Chordoma is a rare tumor. It has unique clinical, pathological and immunohistochemical characteristics. Accurate diagnosis is essential as the tumor shows an aggressive clinical course and requires a multimodal therapeutic approach. A case with wide spread distant metastatic disease that was initially thought to represent metastatic thyroid carcinoma is presented. Appropriate clincopathologic correlation and the histologic findings raised the possibility of poorly differentiated chordoma. The diagnosis was confirmed by immunohistochemistry for INI-1 and Brachyury. The approach to the diagnosis emphasizing the clinical and pathologic findings of this case is discussed and reviewed in the context of the published literature.

Atypical Teratoid Rhabdoid Tumour : From Tumours to Therapies

Atypical teratoid rhabdoid tumours (ATRTs) are the most common malignant central nervous system tumours in children ≤1 year of age and represent approximately 1–2% of all pediatric brain tumours. ATRT is a primarily monogenic disease characterized by the bi-allelic loss of the SMARCB1 gene, which encodes the hSNF5 subunit of the SWI/SNF chromatin remodeling complex. Though conventional dose chemotherapy is not effective in most ATRT patients, high dose chemotherapy with autologous stem cell transplant, radiotherapy and/or intrathecal chemotherapy all show significant potential to improve patient survival. Recent epigenetic and transcriptional studies highlight three subgroups of ATRT, each with distinct clinical and molecular characteristics with corresponding therapeutic sensitivities, including epigenetic targeting, and inhibition of tyrosine kinases or growth/lineage specific pathways.

Atypical Teratoid Rhabdoid Tumour : From Tumours to Therapies

Atypical teratoid rhabdoid tumours (ATRTs) are the most common malignant central nervous system tumours in children ≤1 year of age and represent approximately 1–2% of all pediatric brain tumours. ATRT is a primarily monogenic disease characterized by the bi-allelic loss of the SMARCB1 gene, which encodes the hSNF5 subunit of the SWI/SNF chromatin remodeling complex. Though conventional dose chemotherapy is not effective in most ATRT patients, high dose chemotherapy with autologous stem cell transplant, radiotherapy and/or intrathecal chemotherapy all show significant potential to improve patient survival. Recent epigenetic and transcriptional studies highlight three subgroups of ATRT, each with distinct clinical and molecular characteristics with corresponding therapeutic sensitivities, including epigenetic targeting, and inhibition of tyrosine kinases or growth/lineage specific pathways.

Effect of SMARCB1 on early diagnosis and prognosis of hepatocellular carcinoma / 中国病理生理杂志

AIM: To illuminate the effect of SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily b, member 1 (SMARCB1) in early diagnosis and prognosis of hepatocellular carcinoma (HCC) by determining the clinical expression of SMARCB1 in HCC tissue and benign liver tissue.METHODS: The specific target gene SMARCB1 was selected from these genes by using The Cancer Genome Atlas (TCGA).SMARCB1 expression in HCC tissue and benign liver tissue was measured by immunohistochemistry.Further statistical analysis of TCGA was performed to illuminate the role of SMARCB1 on HCC occurrence and progression.RESULTS: Compared with the benign liver tissue, immunohistochemical staining showed that SMARCB1 expression was significantly up-regulated in the HCC tissue (P<0.01).In addition, SMARCB1 expression was significantly associated with advanced tumor stage (P<0.05).The relation between SMARCB1 expression at mRNA level and clinical prognosis was analyzed.The results indicated that high SMARCB1 expression was an independent prognostic factor for HCC (P<0.05).CONCLUSION: SMARCB1 may play a part as a carcinogenic gene in tumorigenesis.We can distinguish primary HCC samples from non-malignant samples according to its different clinical expression.High SMARCB1 expression probably predicts poor outcome in HCC patients.

The functional role of the CARM1-SNF5 complex and its associated HMT activity in transcriptional activation by thyroid hormone receptor

We have investigated the function and mechanisms of the CARM1-SNF5 complex in T3-dependent transcriptional activation. Using specific small interfering RNAs (siRNA) to knock down coactivators in HeLa alpha2 cells, we found that coactivator associated arginine methyltransferase 1 (CARM1) and SWI/SNF complex component 5 (SNF5) are important for T3-dependent transcriptional activation. The CARM1- SWI/SNF chromatin remodeling complex serves as a mechanism for the rapid reversal of H3-K9 methylation. Importantly, siRNA treatment against CARM1 and/or SNF5 increased the recruitment of HMTase G9a to the type 1 deiodinase (D1) promoter even with T3. Knocking- down either CARM1 or SNF5 also inhibited the down- regulation of histone macroH2A, which is correlated with transcriptional activation. Finally, knocking down CARM1 and SNF5 by siRNA impaired the association of these coactivators to the D1 promoter, suggesting functional importance of CARM1- SNF5 complex in T3-dependent transcriptional activation.