Tony L. Ng

Adverse local tissue reactions (ALTRs) are a prominent cause of hip implant failure. ALTRs are characterized by aseptic necrosis and leukocyte infiltration of synovial tissue. The prevalence of ALTRs in hips with failing metal implants, with highest rates occurring in patients with metal-on-metal articulations, suggests a role for CoCrMo corrosion in ALTR formation. Although hypersensitivity reactions are the most accepted etiology, the precise cellular mechanism driving ALTR pathogenesis...

Hip implants are a successful solution for osteoarthritis; however, some individuals with metal-on-metal (MoM) and metal-on-polyethylene (MoP) prosthetics develop adverse local tissue reactions (ALTRs). While MoM and MoP ALTRs are presumed to be delayed hypersensitivity reactions to corrosion products, MoM- and MoP-associated ALTRs present with different histological characteristics. We compared MoM- and MoP-associated ALTRs histopathology with cobalt and chromium levels in serum and synovial...

CONCLUSIONS: Muscle invasion was associated with higher pathologic tumor staging, poor pathologic factors, and higher rates of positive margin on main specimen.

CONCLUSION: p53 immunohistochemistry may be considered in the initial work-up of a uterine sarcoma, as mutation-type staining would make a fusion-positive sarcoma very unlikely. Mutation-type p53 expression, however, can be seen in a small subset of NTRK1/3-positive sarcomas showing pleomorphic round/ovoid cell histology, which may represent a mechanism of progression in these tumours.

Sclerosing odontogenic carcinoma is a rare locally destructive neoplasm with many histologic mimics. Here the diagnostic challenges are presented of a case of sclerosing odontogenic carcinoma with variable histologic features, including unusual and unexpected negative immunostaining for CK19.

We describe a novel gene fusion, EWSR1-CREM, identified in 3 cases of clear cell carcinoma (CCC) using anchored multiplex polymerase chain reaction, a next-generation sequencing-based technique. CCC is a low-grade salivary tumor recently characterized to have EWSR1-ATF1 fusions in the majority of cases. Three cases of malignant tumor presenting in the base of tongue, lung, and nasopharynx were studied. All cases shared a clear cell morphology with hyalinized stroma, presence of mucin and p63...

Ectopic thymoma in the neck is a rare phenomenon, with fewer than 20 cases reported worldwide. Evidence for management of ectopic thymoma comes from literature for mediastinal thymoma despite clinical features that distinguish the two. Here we present a case of a 31-year-old female with an asymptomatic neck mass who was found to have an ectopic cervical thymoma with concomitant mediastinal thymic hyperplasia. The decision was made to perform a left-sided neck dissection and a video-assisted...

Endometrial stromal sarcomas (ESSs) are mesenchymal uterine tumors characterized by recurrent genetic events, most commonly chromosomal rearrangements, that create oncogenic gene fusions. High-grade endometrial stromal sarcomas (HG-ESSs), as defined in the 2014 World Health Organization Classification, typically contain oncogenic YWHAE-NUTM2 fusions; however, although not well characterized, there are tumors morphologically overlapping with HG-ESS that do not contain the YWHAE-NUTM2 fusions....

The NanoString nCounter assay is a high-throughput hybridization technique using target-specific probes that can be customized to test for numerous fusion transcripts in a single assay using RNA from formalin-fixed, paraffin-embedded material. We designed a NanoString assay targeting 174 unique fusion junctions in 25 sarcoma types. The study cohort comprised 212 cases, 96 of which showed fusion gene expression by the NanoString assay, including all 20 Ewing sarcomas, 11 synovial sarcomas, and 5...

Inflammatory myofibroblastic tumor (IMT) is a genetically heterogenous tumor of the viscera and soft tissues, with multiple molecular features having been demonstrated in this tumor type. About 50% of cases harbor an anaplastic lymphoma kinase (ALK) gene rearrangement, and recent studies have described novel fusions involving the ROS1 and PDGFRβ genes in a subset of ALK-negative cases. However, the molecular features of the remaining subset of cases are not yet defined. We report a case of a...

CONCLUSIONS: Our findings demonstrate good sensitivity and specificity of an NGS-based gene fusion assay in the detection of ESS fusion transcripts.

The etiology of deep dyspareunia in endometriosis is unclear. Our objective was to determine whether nerve bundle density in the cul-de-sac/uterosacrals (zone II) is associated with deep dyspareunia in women with endometriosis. We conducted a blinded retrospective immunohistochemistry study (n = 58) at a tertiary referral center (2011-2013). Patients were stringently phenotyped into a study group and 2 control groups. The study group (tender endometriosis, n = 29) consisted of patients with deep...

Soft tissue myoepithelioma is a rare neoplasm composed of myoepithelial cells. We describe the cytologic features of a soft tissue myoepithelioma arising in the right lower chest wall in a 65-year-old woman. The fine-needle aspiration (FNA) smears showed round to oval, spindle, epithelioid, and plasmacytoid cells in the myxoid background. The nuclei were uniform, round to ovoid, with finely distributed chromatin and eosinophilic or pale cytoplasm, and resembled lobular carcinoma of breast....

We describe how the combination of imaging and histologic findings was essential in establishing a preoperative diagnosis of an extremely rare malignant granular cell tumor (GrCT) occurring in the lower extremity of a 17-year-old man. Magnetic resonance imaging demonstrated a large infiltrative tumor of heterogeneous intermediate signal intensity on both T1- and T2-weighted sequences. Subsequent computed tomography (CT) and fluorodeoxyglucose positron emission tomography CT scans of the patient...

The insulin-like growth factor-1 receptor (IGF1R) is emerging as a promising therapeutic target in human cancers. In the high-risk childhood sarcomas Ewing family tumor and rhabdomyosarcoma, IGF1R-blocking antibodies show impressive antitumor activity in some but not all patients, and acquired resistance is observed. Because tumor IGF1R mutations are not described, the basis of IGF1R inhibitor resistance remains unknown. We hypothesized that compensatory signaling cascades bypassing targeted...