Correlation NKX2.2 IHC and EWSR1 break-apart FISH in the diagnosis of Ewing sarcoma: Can combined NKX2.2 and CD99 immunoexpression obviate or minimize the need of FISH testing? First assessment study from Indian tertiary cancer care center

Context: Ewing sarcoma (ES) are malignant small round cell tumors (MSRCT) characterized by rearrangements of EWSR1 gene. Although gold standard for diagnosis is detection of specific fusion genes by molecular testing, these ancillary tests are costly and only available in limited number of settings. There is a persuasive evidence for reliability of NKX2.2 immunohistochemistry (IHC) as a surrogate marker for EWSR1 gene rearrangement in ES. Aims: The aim of this study is to correlate the NKX2.2 immuno-expression with genetically confirmed ES cases and also to assess the reliability and accuracy of NKX2.2 along with combined positivity of NXX2.2 and CD99 in diagnosing ES and differentiating it from other relevant histological mimics. Settings and Design: The present study is a retrospective study conducted over a period of 6-year duration in a tertiary cancer care center. Methods and Material: We evaluated NKX2.2 immunoexpression in 35 genetically confirmed cases of ES and also in pertaining differential entities (n = 58) of ES including rhabdomyosarcoma (n = 20), lymphoblastic lymphoma (n = 14), Wilms tumor (n = 10), poorly differentiated synovial sarcoma (n = 4), small-cell osteosarcoma (n = 4), neuroblastoma (n = 5), and mesenchymal chondrosarcoma (n = 1). CD99 was performed in the category of MSRCTs showing NKX2.2 positivity to evaluate combined specificity for the diagnosis of ES. Results: Of the 35 genetically confirmed cases of ES, 29 cases (83%) showed NKX2.2-positive expression (83% sensitivity). Compared to ES, NKX2.2 was positive in only 05% cases (3/58 cases) of non-ES MSRCT. Only two of five cases of neuroblastomas and one case of mesenchymal chondrosarcoma showed NKX2.2 positivity. CD99 positivity was seen in 100% of ES and in the single case of mesenchymal chondrosarcoma. All five cases (100%) of neuroblastoma were negative for CD99. Conclusions: The presented study, which is the first from an Indian oncology center, showed NKX2.2 IHC is quite reliable in diagnosis of ES in the right clinicopathological context. With remarkable sensitivity and specificity of NKX2.2 IHC for diagnosis of ES, we propose that combined positivity of CD99 and NKX2.2 IHC can obviate or minimize the need of EWSR1 gene rearrangement molecular testing for diagnosis of ES.

Angiomatoid fibrous histiocytoma: Report of two cases, initially construed as sarcoma with unusual clinico-pathological features

Angiomatoid fibrous histiocytoma (AFH) is a rare soft tissue tumor of uncertain differentiation with low metastatic potential, most commonly occurring in children, adolescents, and young adults, involving extremities. Due to its rare nature and diverse presentation, both clinically and morphologically, it is often misdiagnosed. It becomes important to correctly diagnose this lesion, given its distinct therapeutic implications. Here, we present the clinical, radiologic, and pathologic findings of two rare cases of AFH. Since AFH is a rare soft tissue tumor with low malignant potential, both pathologists and clinicians should be aware of this entity, when encountered with a soft tissue mass in extremities of a child or adolescent, so as to accord appropriate treatment in such cases.

PD-L1 expression in muscle invasive urothelial carcinoma: Comparison of SP142 and SP263 assay

Introduction: High-grade urothelial carcinoma has a different molecular pathway than superficial low grade urothelial carcinoma, and is characterized by genomic instability. The high tumor mutation burden leads to neoantigen formation, evoking an immune response. The immune response has been keenly studied in last two decades and programmed death ligand-1 (PDL-1) has emerged as acceptable immunohistochemical marker for assessment of response to therapy, prognostication and patient selection for immunotherapy. The targeting of PD-1 and PDL-1 by checkpoint inhibitors (CPIs) is an attractive strategy to unblock the inhibitor and induce cytotoxic cell death. However, the presence of complementary and companion diagnostic testing with multiple PDL-1 assays and platforms for various CPIs make a diagnostic quagmire. Thus, it is the need of hour to harmonize these assays. In this undertaken study we evaluated the concordance in PD-L1 expression between the two PD-L1 clones: SP263 and SP142, in treatment naïve muscle invasive bladder cancer (MIBC). Methods: We evaluated Ventana PD-L1 “SP263 and SP142” qualitative immunohistochemical assay using rabbit monoclonal anti-PD-L1 clones in evaluation of PDL-1 immunoexpression on Ventana autostainer platform. The study includes 30 muscle invasive urothelial carcinomas, with 10 of 30 having nodal metastasis. Results: SP263 assay was statistically more sensitive than SP142 for tumor cell (TC) scoring (P = 0.0009), whereas SP142 was more sensitive for immune cell (IC) scoring (P = 0.0067). There was no statistical significant discordance for TC or IC scoring between primary tumor and metastatic lymph node. Conclusion: PD-L1 testing status can be done on both primary tumor and metastatic site, however in metachronous metastatic setting, testing on recent metastatic site should be preferred. The harmonization of immunoexpression between 2 PD-L1 clones could not be achieved.

Molecular stratification of high-grade urothelial carcinoma by immunohistochemistry with its histomorphological and clinical correlation

Introduction: Urothelial carcinoma poses a significant cause of morbidity and mortality. The recent classification of Tumors of Urinary System by World Health Organization fourth edition) has elucidated its molecular subtypes and its associated prognostic significance. Methods: We used immunohistochemistry marker expression (CK5/6, CK20, CD44, EGFR) as a surrogate marker, to stratify 150 cases of high-grade urothelial carcinoma into the intrinsic molecular subtypes. A correlation was also done with immunohistochemical markers p53, p21, E-cadherin and Ki-67. Results: On subtyping, 47.3% cases were basal, 42.7% luminal and 10% remained unclassified. We did not find GATA3 useful for molecular stratification in our study. Muscle invasion was seen in 59% of basal and 31% of luminal subtype (P = 0.016). Squamous differentiation was most commonly associated with basal subtype (P < 0.001). EGFR expression was seen in 62% of basal and 38% of luminal subtype (P = 0.014), and thus can be used as an additional marker for molecular stratification. Overexpression of p53 was seen in 64% cases of muscle invasive and 36% of non-muscle invasive high-grade carcinomas (P < 0.0001). An inverse relationship was observed between p53 and p21 immunoexpression (r = –0.494) (P < .0001). The overall survival at 1- and 2-year interval was more in the luminal subtype, suggesting an early mortality in basal group, (P = 0.827), and at 6 years both the groups had almost similar results. Conclusion: High-grade urothelial carcinoma is challenging in terms of therapeutic strategy. Increased understanding of underlying molecular basis helps identifying targetable treatment options, and newer biomarkers will enhance predictive and prognostic stratification.

Intraventricular metastasis from carcinoma breast masquerading as choroid plexus neoplasm: A case report

Metastatic tumors in the brain represent the most common type of intracranial neoplasm, comprising 8–10% of all brain tumors. 30% of such tumors are primarily of breast origin in females. Brain parenchymal metastasis is the more common presentation. Intraventricular spread is rare, seen in less than 5% of cases in a metastatic scenario. Here, we report a case of 41-year-old female presenting with intraventricular brain metastasis in a follow-up case of carcinoma breast. Five years post-surgery, the patient presented with complaints of headache. On evaluation, magnetic resonance imaging (MRI) brain showed an intraventricular lesion in the fourth ventricle. She was operated on for the same and the biopsy revealed a tumor with a complex papillary pattern resembling choroid plexus papilloma. On immunohistochemistry (IHC), the tumor cells were positive for cytokeratin 7 (CK7), Epithelial membrane antigen (EMA), GATA3, and mammaglobin favoring a metastasis from breast origin. Hence, a possibility of brain metastasis should be kept in mind in patients presenting with solitary ventricular masses due to the lack of definite radiological characteristics in such locations and histological overlap. Also, organ-specific IHC is a must in today's evidence-based era as is reflected in our case.

Epithelioid haemangioma of bone: A series of four cases with a revision of this contentious entity

Epithelioid hemangioma of bone is a rare and locally aggressive vascular neoplasm of bone associated with a good prognosis. Because of its worrisome histomorphologic features and aggressive clinicoradiologic findings, at times with multifocal presentation, they tend to simulate malignant tumors. We report a series of four cases of epithelioid hemangioma of bone with their clinicopathologic characteristics. All had adjacent soft tissue involvement and two had multifocal bone disease. Microscopically, all cases had a tumor in lobular configuration, composed of epithelioid endothelial cells with the formation of well-formed vessels or grew in solid sheets. The tumor cells lacked significant cytologic atypia, necrosis, and increased mitosis. All cases were immunohistochemically positive for vascular markers CD34, CD31, ERG1, whereas negative for CK. Two of the cases were treated with excision, and the other two underwent curettage. None had local recurrence or metastasis on follow-up. This study highlights the importance of recognizing histomorphological and clinicoradiological features for distinguishing epithelioid hemangiomas from malignant vascular neoplasms of bone because of their distinct therapeutic implications and clinical outcomes.

Immunophenotyping of male breast cancer - Experience at a tertiary care centre

Background: Male breast cancers (MBCs) are uncommon and account for 1% of all breast cancers. Medical conditions that increase the estrogen to testosterone ratio are implicated as the risk factors. Morphologically similar, but MBCs have biological differences compared with female breast cancer (FBC). Purpose: The present study was aimed to examine the immunophenotype of MBC, subsequent molecular subtypes, their association with clinicopathological features, and prognosis. Materials and Methods: We analyzed clinicopathological features of 42 cases of MBC, and classified them according to molecular classification using immunohistochemistry (IHC). This is the second largest study from India. Results and Conclusion: Median age of patients was 61 years (age range: 41-87 years). Invasive duct carcinoma comprised 95.2% of cases. Tumor grade II and III was seen in 50% and 47.6% of cases, respectively, and advanced stage disease (III/IV) was seen in 45.2% cases (n = 39). Estrogen receptor (ER) was positive in 97.6% cases, progesterone receptor (PR) in 83.3%, androgen receptor (AR) in 76.2%, HER2 in 4.8%, Cyclin-D1 in 92.9%, Bcl2 in 66.7%, GCDFP-15 in 23.8%, p53 in 16.7%, and Ki67 index was low (<14%) in 66.7% cases. Molecular subtyping of these cases revealed 64.3% of luminal A, 35.7% of luminal B, and no HER2 rich/driven category or triple negative case. There was no statistical significance between luminal A and B category pertaining to overall stage of tumor (P = 0.905). Lymph node metastasis was more commonly associated with luminal B category (P = 0.089). p53 positivity showed significant association with luminal A cases (P = 0.002) and nodal metastasis (P = 0.042). GCDFP-15 positivity showed significant association with higher tumor grade (P = 0.042) and stage (P = 0.047). Stage was the most significant prognostic marker (P < 0.0001). On follow-up (n = 27), all the six cases that showed recurrence/persistent disease were high stage (III/IV) on presentation.

Sturge Weber syndrome.

A variant of hemangioma and an uncommon congenital condition, the Sturge Weber syndrome (SWS), also called encephalo trigeminal angiomatosis, is a neurocutaneous disorder with angiomas involving the skin of the face (cutaneous angioma) and pia arachnoid (leptomeningeal angioma). It occurs typically in the ophthalmic and maxillary distributions of the trigeminal nerve (1,2). Here we present a case of a 14 year old girl.

Incidence of neural tube defects of Lucknow over a 10 year period from 1982-1991.

Open neural tube defects (NTD) in babies, occurring over a 10 yr period (1982-91), in four major maternity hospitals of Lucknow, were identified to analyse the incidence of this disorder. The overall incidence of NTD was found to be 3.9/1000. It was significantly higher in the teaching hospital compared to non-teaching hospitals. But there was no significant difference in the incidence of NTD between the Government and Private hospitals. During the decade (1982-91) under study there was no decline in NTD births. These data could serve as base-line for the incidence of NTD in north India, as NTD is expected to decline with the introduction of folic acid for the prevention of NTD.