Isolated Infiltrative Optic Neuropathy in an Acute Lymphoblastic Leukemia Relapse.

Optic nerve infiltration as the first sign of isolated central nervous system relapse of acute lymphoblastic leukemia (ALL) is rare. A seven-year-old girl with standard-risk B-cell ALL who was in remission presented with sudden onset of left eye pain and loss of vision. Examination revealed no perception to light in the left eye with positive relative afferent pupillary defect. The optic disc was hyperemic and swollen with total obscuration of the disc margin associated with central retinal artery and vein occlusion. Magnetic resonance imaging of the brain and optic nerve showed left intraorbital optic nerve thickening associated with perineural enhancement and intraconal fat involvement. Lumbar puncture revealed leukemic infiltration with blast cells after a week of eye symptoms, while bone marrow aspiration was negative for malignant cells. A diagnosis of left leukemic optic nerve infiltration with central retinal artery and vein occlusion was made. A high index of suspicion with repeat cerebrospinal fluid sampling is crucial to confirm the diagnosis as vitreous biopsy may fail to reveal infiltrative cells.

HER2 testing by immunohistochemistry in breast cancer: A multicenter proficiency ring study.

BACKGROUND: Human epidermal growth factor receptor 2 (HER2) over-expression in breast cancer is associated with aggressive tumor behavior and predicts response to targeted therapy. Accurate HER2 result is paramount for optimal patient management. However, routine HER2 immunohistochemistry (IHC) testing are subjected to intra- and inter-laboratory variability. OBJECTIVE: This study aims to determine inter-laboratory variation in HER2 IHC testing through a slide-exchange program between five main reference laboratories. METHOD: A total of 20 breast carcinoma cases with different known HER2 expression and gene status were selected by the central laboratory in five testing rounds. Three unstained tissue sections from each case were sent to participating laboratories, which immunostained and interpreted the HER2 immunohistochemistry result. One of the stained slides was sent to one designated participating laboratory for evaluation. Results were analyzed by the central laboratory. RESULTS: A complete concordance was achieved in six IHC-positive and six IHC-negative cases, its gene status of which was confirmed by in-situ-hybridization (ISH) study. The discordant results were observed in six equivocal cases, one negative case and one positive case with a concordance rate of 50-88.3%. Interestingly, the negative discordant case actually displays tumor heterogeneity. Good inter-observer agreement was achieved for all participating laboratories (k = 0.713-1.0). CONCLUSION: Standardization of HER2 testing method is important to achieve optimum inter-laboratory concordance. Discordant results were seen mainly in equivocal cases. Intra-tumoral heterogeneity may impact the final HER2 IHC scoring. The continuous quality evaluation is therefore paramount to achieve reliable HER2 results.

A case of surgically resected cardiac rhabdomyoma with progressive left ventricular outflow tract obstruction.

Cardiac rhabdomyoma is the most prevalent cardiac tumors in the pediatric population, in close association with tuberous sclerosis complex. It is usually detected antenatally or postnatally by echocardiography. Clinical presentations depend greatly on the size and position of the tumor mass. Interestingly, rhabdomyoma has a propensity to regress spontaneously and is not usually operated upon, unless the patient becomes hemodynamically compromised. Herein, we report an unusual case of surgically treated cardiac rhabdomyoma in a baby boy presented at birth with a progressive enlarging intraventricular mass, complicated with left ventricular outflow tract obstruction 7 weeks later. Histopathological examination of the intracardiac mass revealed sheets of tumor cells with spider-like morphology (known as "spider cells"), confirmed the diagnosis of rhabdomyoma. Close disease monitoring of patient's hemodynamic status in a newly diagnosed cardiac rhabdomyoma is inevitable as the tumor, although rare, may progress.

Warthin-Starry Staining for the Detection of Helicobacter pylori in Gastric Biopsies.

BACKGROUND: Warthin-Starry (WS) staining is an ancillary stain used in the detection of Helicobacter sp., spirochaete and other microorganisms in tissue sections. The present study aimed to determine the validity of WS stain in the confirmation of H. pylori diagnosis in gastric biopsies in comparison with anti-H. pylori immunohistochemistry (IHC) staining. METHODS: This study involved 104 cases of gastric biopsies that were previously subjected to WS staining. All cases involved retrieval of formalin-fixed paraffin-embedded (FFPE) gastric biopsies that were re-cut, subjected to anti-H. pylori IHC staining and reviewed blindly by a pathologist. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of WS as compared to IHC were calculated. RESULTS: In this study, WS stain was less sensitive in detecting H. pylori. The sensitivity, specificity, PPV and NPV for WS stain were 50.0%, 92.4%, 79.2% and 76.3%, respectively. CONCLUSIONS: The sensitivity of WS stain in the histopathology laboratory was lower than that described previously. Several external factors that might influence the results were identified. However, sufficient information on patients' history of treatment and medication would be required for the diagnosis or confirmation of the presence of H. pylori in gastric biopsies by WS staining.

Ectopic adrenal tissue associated with borderline mucinous cystadenoma of ovary: a case report with review of the literature.

Ectopic adrenal tissue in the ovary is a rare entity. We reported a case of ectopic adrenal tissue in borderline mucinous cystadenoma of the left ovary. A 22 year-old student presented with progressive abdomen distension associated with discomfort for 3 months. Imaging investigation was suggestive of mucinous left ovarian cyst. Left salpingo-oophorectomy was performed and the histopathology revealed borderline mucinous cystadenoma with an incidental finding of ectopic adrenal tissue. This is an interesting case because of its rarity and potential risk of neoplasm changes.

Giant Cell Tumor of the Ribs and Aneurysmal Bone Cyst Presenting With Hemothorax in a Child.

Giant cell tumor (GCT) is one of the most common tumors of bone and is the most common precursor of aneurysmal bone cysts (ABC). The clinical behavior of concurrent GCT and ABC can be very aggressive in children. GCT of the ribs, with or without ABC, is rarely seen in children. We report a case of an 8-year-old girl with GCT and associated ABC of the ribs who presented with sudden onset of chest pain and breathlessness due to a hemothorax. The patient was successfully treated by surgical resections and arterial embolization. She has remained well for 4 years after the initial surgery.