Primary sinonasal Ewing sarcoma: A case report.

BACKGROUND: Ewing sarcoma (ES) is an aggressive tumour which is typically skeletal in origin. ES involving the head and neck region is uncommon and can be easily confused with other small round blue cell tumours. We herein present a rare case of ES involving the sinonasal area. CASE PRESENTATION: A 5-year-old Somalian boy with no known medical illness presented with progressive nasal blockage associated with clear nasal discharge and intermittent spontaneous epistaxis for three months. CT paranasal sinus and neck region revealed poorly enhancing expansile mass in the right maxillary sinus with areas of necrosis within. Initial radiological differential diagnoses were lymphoma and rhabdomyosarcoma. The mass was biopsied and histologically showed diffuse sheets of small round blue cells that was positive to CD99, NSE and vimentin. The muscle and lymphoid markers were negative. Fluorescence in-situ hybridisation (FISH) study revealed the presence of EWSR1 gene rearrangement thus diagnosis of ES was rendered. CONCLUSIONS: ES of sinonasal tract is a rare entity and its pathological features significantly overlap with others small round blue cells tumour. Demonstration of EWSR1 gene translocation is recommended for the diagnosis of ES particularly at uncommon sites.

Gastric Schwannoma in an elderly man: A case report.

Schwannomas are mesenchymal tumors that are characteristically benign and slow growing, which originate from any nerve with Schwann cell sheath. Gastrointestinal schwannomas are rare with distinct morphologic features as compared to schwannomas of soft tissue or central nervous system. A 77-year-old male patient was diagnosed with gastrointestinal stromal tumor based on radiological findings and clinical impression when he presented with worsening abdominal discomfort and pain. He underwent distal gastrectomy however histopathological examination of the tumour revealed schwannoma. This case report presents a rare case of a symptomatic gastric schwannoma, whose definitive diagnosis was established by histopathological and immunohistochemical findings postoperatively.

Parotid gland oncocytic carcinoma: A rare entity in head and neck region.

Oncocytic carcinoma of the salivary gland is an uncommon tumour in the head and neck region. Owing to its rarity, identifying the histopathological features of a malignant tumour can be difficult and challenging. We report a case of a 70-year-old man who presented with a left facial weakness for six months in a background history of left parotid swelling over the past 10 years. Clinical examination revealed a 3x3cm left parotid mass and grade 4 facial nerve palsy. Fine needle aspiration of the mass showed scattered cohesive, monolayered sheets of uniform oncocytic cells. Subsequently, a left total parotidectomy and selective neck dissection were performed. Histological examination showed sheets of small oncocytes with minimal nuclear atypia. Evidence of nerve entrapment, capsular invasion and perivascular permeation were identified in focal areas. Thus, a final diagnosis of oncocytic carcinoma was rendered.

A comparison study of HER2 protein overexpression and its gene status in breast cancer.

INTRODUCTION: Evaluation of HER2 status in breast cancer using immunohistochemistry (IHC) and in-situ-hybridisation (ISH) study is important to establish prognosis and to select patient for targeted therapy. OBJECTIVE: The study aims to determine the concordance between HER2 protein IHC score and its gene status by dual-colour dual-hapten in-situ-hybridization (DDISH) study. MATERIALS AND METHODS: Retrospective study was performed on 767 referred breast cancer cases over a period of five years. The HER2 IHC score (the initial and repeat test score) and the results of HER2 gene status by DDISH were retrieved from the histopathological reports. The agreement between initial IHC score with repeat test score was measured using Cohen Kappa. Chi square test analyzed the association between HER2 IHC score with its gene status by DDISH. RESULTS: The concordance of HER2 IHC score between the initial and repeat test were 52.7% and 89.4% for IHC score 2+ and 3+ respectively. There was moderate agreement of HER2 IHC score between the initial and repeat test score (Ï° = 0.526, p<0.001). A significant association noted between HER2 IHC score with its gene status by DDISH (p<0.001). Only 56 out of 207 cases (27.1%) with 2+ IHC score showed HER2 gene amplification while the majority of cases with 3+ IHC score were gene-amplified (446 out of 451, 98.9%). CONCLUSION: ISH study should be done in all IHC-equivocal cases (2+) to select patient for targeted therapy. Gene amplification must also be confirmed in IHC-positive cases (3+) to prevent from giving non-effective treatment with possible adverse effects to patient with non-amplified HER2 gene.

Gleason scores in prostate needle biopsy and prostatectomy specimens in prostatic adenocarcinoma: A correlation study.

INTRODUCTION: Gleason scoring (GS) categorised prostatic adenocarcinoma into five prognostic grade groups (PGGs); associated with different prognosis and treatment. This study aims to correlate between Gleason scores of needle biopsies with the corresponding total prostatectomy specimens, and to assess the relationship between the percentage of Gleason 4 tumour pattern (GP4) within Gleason score 7 (GS7) needle biopsy groups with the pathological staging. MATERIALS AND METHODS: Seventy-eight specimens of needle prostate biopsy and its subsequent radical prostatectomy were retrospectively studied. The GSs of the needle biopsy were compared with the corresponding prostatectomy specimens. The percentage of GP4 in GS7 needle biopsy groups was calculated and correlated with the pathological staging. RESULTS: More than half (60%) of GS 6 needle biopsy cases (PGG 1) were upgraded in the prostatectomy specimen, while the majority (80%) of the GS7 needle biopsy groups (PGG 2 and 3) remain unchanged. Cohen's Kappa shows fair agreement in the Gleason scoring between needle biopsies and prostatectomy specimens, K = 0.324 (95% CI, 6.94 to 7.29), p <0.0005 and in the percentage of GP4 in GS7 needle biopsy groups and their corresponding radical prostatectomy specimens, K = 0.399 (95% CI 34.2 - 49.2), p<0.0005. A significant relationship was seen between the percentage of GP4 in GS7 needle biopsy with the pT and pN stage of its radical prostatectomy (p = 0.008 and p=0.001 respectively). CONCLUSION: A higher percentage of GP4 in GS7 tumour is associated with worse tumour behaviour, therefore it is crucial for clinicians to realise this in deciding the optimal treatment.

Intraoperative frozen section sentinel lymph node assessment in breast cancer: A tertiary institution experience.

INTRODUCTION: Intraoperative frozen section lymph node assessment helps to predict axillary lymph node metastasis in breast cancer. However, the accuracy of this frozen section analysis may vary among institutions. This study describes our institution's experience in intraoperative analysis of sentinel lymph node and aims to determine the accuracy, sensitivity and specificity of our assessment. MATERIALS AND METHODS: We retrospectively analysed the histopathological material and data from 82 breast cancer patients diagnosed over a period of four years who underwent intraoperative frozen section evaluation of sentinel lymph nodes. RESULTS: Frozen section analysis detected metastasis in 13 out of 82 cases and definitive pathological examination on the paraffin section confirmed these positive findings. There was no false positive case (specificity of 100%). The true positive cases comprised seven macrometastases, five micrometastases and one isolated tumour cells. Sampling error was noted in two cases in which the malignant cells were only present in the deeper final paraffin sections (false negative rate of 13.3%). The test sensitivity was 86.7% and the accuracy rate was 97.5%. These findings are comparable to other published data. CONCLUSION: Intraoperative frozen section analysis is a safe and reliable method for assessment of sentinel lymph node. Knowledge on limitation of frozen section analysis with diligent evaluation of frozen section specimen will be beneficial in reducing interpretation error.