Noor Akmal Sharifah

Minichromosome maintenance protein 2 is a reliable proliferative marker in breast carcinoma

This is a study aimed to examine the distribution pattern of a specific minichromosome maintenance protein 2 (MCM2) in benign and malignant breast tissue. We also aim to correlate the frequency of expression of MCM2 with the degree of tumor differentiation. We used immunohistochemistry to examine the distribution and expression pattern of MCM2 on formalin-fixed paraffin-embedded tissue sections of benign (n = 30) and malignant breast tissue (n = 70) (IDC 56, DCIS 4, ILC 2, nonductal 4, mixed type 4). We quantified MCM2 expression by calculating a labeling index, which represents the percentage of epithelial nuclei that stained positively. Immunoreactivity was heterogenous in all the 70 malignant cases examined. Epithelial cells in cycle are most frequent at the tumor periphery. Labeling index of MCM2 was greatest in grade 3 (poorly differentiated) and lowest in grade 1 tumors (well differentiated). Minichromosome maintenance protein 2 expression in breast cancer showed a positive association with histologic grade (P < .05). In all the benign breast tissue examined, no proliferating compartments could be characterized. Minichromosome maintenance protein 2 is a useful proliferative marker of breast carcinoma. The frequency of expression of MCM2 showed an inverse correlation with the degree of tumor differentiation.

Identification of novel large genomic rearrangements at the BRCA1 locus in Malaysian women with breast cancer

BACKGROUND The incidence of breast cancer has been on the rise in Malaysia. It is suggested that a subset of breast cancer cases were associated with germline mutation in breast cancer susceptibility (BRCA) genes. Most of the BRCA mutations reported in Malaysia were point mutations, small deletions and insertions. Here we report the first study of BRCA large genomic rearrangements (LGRs) in Malaysia. We aimed to detect the presence of LGRs in the BRCA genes of Malaysian patients with breast cancer. METHODS Multiplex ligation-dependent probe amplification (MLPA) for BRCA LGRs was carried out on 100 patients (60 were high-risk breast cancer patients previously tested negative/positive for BRCA1 and BRCA2 mutations, and 40 were sporadic breast cancer patients), recruited from three major referral centres, Universiti Kebangsaan Malaysia Medical Centre (UKMMC), Hospital Kuala Lumpur (HKL) and Hospital Putrajaya (HPJ). RESULTS Two novel BRCA1 rearrangements were detected in patients with sporadic breast cancer; both results were confirmed by quantitative PCR. No LGRs were found in patients with high-risk breast cancer. The two large genomic rearrangements detected were genomic amplifications of exon 3 and exon 10. No BRCA2 genomic rearrangement was found in both high-risk and sporadic breast cancer patients. CONCLUSION These results will be helpful to understand the mutation spectrum of BRCA1 and BRCA2 genes in Malaysian patients with breast cancer. Further studies involving larger samples are required to establish a genetic screening strategy for both high-risk and sporadic breast cancer patients.

Genome-wide analysis of oral squamous cell carcinomas revealed over expression of ISG15, Nestin and WNT11

BACKGROUND Multistep pathways and mechanisms are involved in the development of oral cancer. Chromosomal alterations are one of such key mechanisms implicated oral carcinogenesis. Therefore, this study aims to determine the genomic copy number alterations (CNAs) in oral squamous cell carcinoma (OSCC) using array comparative genomic hybridization (aCGH) and in addition attempt to correlate CNAs with modified gene expression. MATERIALS AND METHODS Genome-wide screening was performed on 15 OSCCs using high-density aCGH. On the basis of pathway analysis, three genes (ISG15, Nestin and WNT11) which mapped to CNA regions were selected for further evaluation of their mRNA expression using quantitative reverse transcriptase PCR (qRT-PCR). RESULTS Copy number alterations were observed on multiple genomic regions, including amplifications on 1p, 3q, 5p, 6p, 7p, 8q, 9q, 11q, 12q, 16p, 18p and deletions on 3p, 7q, 8p, 11q, 19q and 20q. Among the three selected genes, ISG15 had the highest mRNA expression level with a 22.5-fold increase, followed by Nestin with a 4.5-fold increase and WNT11 with a 2.5-fold increase. CONCLUSIONS This study has identified several major CNAs in oral cancer genomes and indicated that this correlates with over expression of the ISG15, WNT11, and Nestin genes.

Fluorescence in situ hybridization analysis using PAX8- and PPARG-specific probes reveals the presence of PAX8-PPARG translocation and 3p25 aneusomy in follicular thyroid neoplasms

At the present time, the differentiation between follicular thyroid carcinoma (FTC) and adenoma can be made only postoperatively and is based on the presence of capsular or vascular invasion. The ability to differentiate preoperatively between the malignant and benign forms of follicular thyroid tumors assumes greater importance in any clinical setting. The PAX8-PPARG translocation has been reported to occur in the majority of FTC. In this study, a group of 60 follicular thyroid neoplasms [18 FTC, 1 Hurthle cell carcinoma (HCC), 24 follicular thyroid adenomas (FTA), 5 Hurthle cell adenomas (HCA), and 12 follicular variants of papillary thyroid carcinomas (FV-PTC)] were analyzed to determine the prevalence of the PAX8-PPARG translocation by fluorescence in situ hybridization. The PAX8-PPARG translocation was detected in 2/18 FTC (11.1%). In addition, 2/18 (11.1%) FTC and 1/5 (20%) HCA showed 3p25 aneusomy only. The frequency of the translocation detected in the study was lower compared to the earlier studies conducted in Western countries. This might be attributed to the ethnic background and geographic location. Detection of either the PAX8-PPARG translocation or the 3p25 aneusomy in FTC indicates that these are independent genetic events. It is hereby concluded that 3p25 aneusomy or PAX8-PPARG translocation may play an important role in the molecular pathogenesis of follicular thyroid tumors.

Genetic Alterations of Chromosome 8 Genes in Oral Cancer

The clinical relevance of DNA copy number alterations in chromosome 8 were investigated in oral cancers. The copy numbers of 30 selected genes in 33 OSCC patients were detected using the multiplex ligation-dependent probe amplification (MLPA) technique. Amplifications of the EIF3E gene were found in 27.3% of the patients, MYC in 18.2%, RECQL4 in 15.2% and MYBL1 in 12.1% of patients. The most frequent gene losses found were the GATA4 gene (24.2%), FGFR1 gene (24.2%), MSRA (21.2) and CSGALNACT1 (12.1%). The co-amplification of EIF3E and RECQL4 was found in 9% of patients and showed significant association with alcohol drinkers. There was a significant association between the amplification of EIF3E gene with non-betel quid chewers and the negative lymph node status. EIF3E amplifications did not show prognostic significance on survival. Our results suggest that EIF3E may have a role in the carcinogenesis of OSCC in non-betel quid chewers.

Alveolar rhabdomyosarcoma of the left hand with bilateral breast metastases in an adolescent female.

Rhabdomyosarcoma is a common extramammary malignancy in pediatric age groups, but it rarely metastasizes to the breast. Breast rhabdomyosarcomas are commonly metastatic, with possible primary locations at the head and neck, trunk, extremities, retroperitoneum and perianal region. We report a case of primary alveolar rhabdomyosarcoma of the upper extremities in a 17-year-old adolescent female who presented with bilateral lower limb weakness and bilateral breast lumps.

Dendritic fibromyxolipoma: A variant of spindle cell lipoma with extensive myxoid change, with cytogenetic evidence

Dendritic fibromyxolipoma (DFML), a rare, recently described distinct benign soft tissue tumor, has many clinicopathological features reminiscent of spindle cell lipoma and solitary fibrous tumor with myxoid change. It is distinguished histologically from both entities by the presence of spindle and stellate cells with dendritic cytoplasmic prolongations, prominent myxoid stroma with abundant keloidal collagen and occasional small plexiform vascular proliferation. We describe a case of histologically confirmed DFML of the left shoulder in a 67‐year‐old male, in which subsequent cytogenetic analysis revealed deletion involving 13q14.3 region in all the tumor cells, typically detected in spindle cell lipoma. In the presence of many clinicopathological similarities between DFML and spindle cell lipoma including chromosomal abnormalities, we postulate that DFML is merely a rare variant of spindle cell lipoma with extensive myxoid degeneration, and may not be considered as a separate entity. The possible differential diagnosis and their distinguishing features are briefly discussed.

FISH analysis using PPAR γ-specific probes for detection of PAX8-PPAR γ translocation in follicular thyroid neoplasms.

Fluorescence in situ hybridization (FISH) is increasingly gaining importance in clinical diagnostics settings. Due to the ability of the technique to detect chromosomal abnormalities in samples with low cellularity or containing a mixed population of cells even at a single-cell level, it has become more popular in cancer research and diagnosis. Here, we describe the FISH technique for detection of PAX8-PPARγ translocation in follicular thyroid neoplasms, and the optimal protocol for the detection of this fusion gene using in archival formalin-fixed paraffin-embedded (FFPE) thyroid tissue sections.

Intrathyroidal oxyphilic parathyroid carcinoma: A potential diagnostic caveat in cytology?

Oxyphilic (oncocytic) parathyroid lesions are very uncommon and their cytological features are rarely described. Due to the similarities in anatomical location and indistinguishable cytomorphological features, these lesions are easily confused with neoplastic and non‐neoplastic thyroid lesions on fine needle aspiration (FNA). The diagnosis becomes more challenging in cases of unusual intrathyroidal location of the parathyroid lesions in the absence of clinical evidence of hyperparathyroidism, which simulate thyroid nodules clinically. We describe a case of intrathyroidal oxyphilic parathyroid carcinoma in a 66‐year‐old female, who presented with a dominant left “thyroid” nodule. FNA smears were cellular, comprising predominantly of oxyphilic cells arranged in papillary‐like architecture with occasional nuclear grooves, which was mistaken for oncocytic variant of papillary carcinoma of the thyroid. The histological diagnosis of oxyphilic parathyroid “adenoma” was made following total thyroidectomy. The tumor, unfortunately, recurred 7 years later with associated multiple lung metastases. When dealing with thyroid lesions comprising predominantly of oncocytic cells, one should consider oxyphilic parathyroid neoplasms as one of the differential diagnosis. In difficult equivocal cases, a panel of immunocytochemical stains (PTH, GATA3, TTF‐1, PAX8, and thyroglobulin) can be helpful. In addition, a combination of valuable clinical, radiological, and laboratory data, including serum calcium and parathyroid hormone levels are key to arriving at an accurate cytological diagnosis. Diagn. Cytopathol. 2016;44:688–692.