Primary central nervous system lymphoma: Comprehension of cell-of-origin subtypes.

Primary central nervous system diffuse large B-cell lymphoma (PCNS-DLBCL) is an uncommon extranodal lymphoma that accounts for more than 95% of all the CNS lymphomas. Unlike its systemic/nodal counterpart, which is currently subtyped into cell-of origin (COO) subtypes, its feasibility and utility are largely debatable in PCNS-DLBCL. Objectives: To classify PCNS-DLBCL into COO-subtypes based on immunohistochemical algorithms by Hans and Choi and evaluate concordance between the two. A further aim is to investigate the clinicoradiological and histomorphological parameters of the subtypes thus obtained. Materials and Methods: As many as 143 cases of primary CNS lymphoma were evaluated by immunohistochemistry for CD10, BCL6, MUM1, GCET, and FOXP1 and based on which the said 143 cases were further classified into COO subtypes using Hans and Choi algorithms. Results: Mean age was 53.8 years with marginal male preponderance and predominantly centroblastic morphology (75.5%). CD 10 was positive in 8.9% of the cases, BCL6 in 58.6%, MUM1 in 89.9%, GCET in 32.9%, and FOXP1 in 79.5%. As much as 84.9% cases were of non-germinal center B-cell (GCB) subtype and 15.1% cases were of GCB subtype as determined based on Hans algorithm. Furthermore, 90.7% cases were of activated B-cell (ABC) subtype and 9.3% cases were of GCB subtype according to Choi algorithm. A 91.8% concordance was observed between Hans and Choi algorithms. Among the 6 discordant cases, 5 cases were subtyped as GCB by Hans and ABC by Choi and 1 case as ABC by Hans and GCB by Choi. Conclusion: Most of PCNS-DLBCLs are of non-GCB/ABC COO subtype, but inconsistences abound in the utility of IHC algorithms in PCNS-DLBCL COO subtypes.

Validation of Dual-Color Dual In Situ Hybridization for HER2/neu Gene in Breast Cancer.

CONTEXT: Human epidermal growth factor (HER2/neu) gene amplification, a poor prognostic factor in invasive breast cancer, has shown substantial utility as a predictive marker, with significantly improved survival following anti-HER2 therapies like trastuzumab. Dual-color dual in situ hybridization (D-DISH), a recently introduced fully automated assay for HER2/neu evaluation on light microscopy, has several advantages over fluorescence in situ hybridization (FISH). OBJECTIVE: To standardize and validate the D-DISH assay using FISH as the gold standard and assess interobserver reproducibility in interpreting the D-DISH assay. DESIGN: D-DISH was performed using the latest HER2 Dual ISH DNA Probe Cocktail assay (Ventana Medical Systems Inc, Tucson, Arizona) in 148 cases of invasive breast cancer. The same block was used for performing immunohistochemistry by Ventana PATHWAY anti-HER2/neu (4B5) antibody and FISH assay by ZytoLight SPEC ERBB2/CEN17 Dual Color Probe. D-DISH was separately interpreted by 4 pathologists blinded to FISH results. RESULTS: Concordance of 98.65% and a Cohen κ value of 0.97 were observed between FISH and D-DISH. Intraclass correlation coefficient (0.93-0.97) and κ values (0.98-1.0) for interobserver reproducibility showed almost perfect agreement by D-DISH. Interobserver reproducibility was also evaluated for genomic heterogeneity, HER2 group categorization, and polysomy (κ values 0.42-0.74, 0.89-0.93, and 0.98-1.0, respectively). CONCLUSIONS: We successfully validated the latest version of D-DISH assay as a substitute for FISH in predicting HER2 gene status with significant interobserver reproducibility, concluding that this D-DISH assay may be introduced in routine diagnostic services as a reflex test to ascertain HER2 gene status.

Programmed cell death ligand - 1 expression in triple negative breast carcinoma and its prognostic significance in Indian population.

BACKGROUND: The programmed cell death protein - 1 (PD-1) - programmed cell death ligand - 1 (PD-L1) axis is emerging as a promising target for immunotherapy in triple-negative breast cancers (TNBC). AIMS: We analyzed the expression of PD-L1 in TNBC cases, with special emphasis on lymphocyte-predominant tumors along with correlation of the same with clinicopathological features and outcome. SETTINGS AND DESIGN: Tissue microarrays (TMA) were prepared from resection specimens of TNBC cases diagnosed from 2004 to 2008. SUBJECTS AND METHODS: Immunohistochemical staining was performed on the TMA using the ventana PD-L1 antibody (Clone SP 263). STATISTICAL ANALYSIS: Chi-square test was used for correlation of PD-L1 positivity in tumor and immune cells with clinicopathological features. Univariate and multivariate survival analyses were carried out using the Kaplan Meir and Cox Regression methods, respectively. RESULTS: Overall, PD-L1 staining was seen in 35.9% (66 out of 184) tumors. PD-L1 positivity of tumor cells was seen in 14.7% (27 out of 184 cases), whereas stromal immune cell expression was observed in 21.2% (39 out of 184) cases. Lymphocyte-predominant tumors showed statistically significant expression of PD-L1 in both tumor (P < 0.0001) and immune cells (P 0.036). On univariate analysis, PD-L1 in immune cells was associated with good overall survival (P 0.05) as well as disease-free survival (P 0.013). On multivariate analysis, the same was associated with a significantly decreased risk for recurrence (P 0.018). CONCLUSION: PD-L1 expression in stromal immune cells proved to be a significant prognostic factor for TNBC. This data can serve as a baseline to plan clinical trials with anti-PD-L1 drugs for TNBC in the Indian setting.

Hyperechoic Lesions on Breast Ultrasound: All Things Bright and Beautiful?

Ultrasound (US) lexicon of the Breast Imaging Reporting and Data System (BI-RADS) defines an echogenic breast mass as a lesion that is hyperechoic in comparison with subcutaneous adipose tissue. However, at sonography, only 0.6 to 5.6% of breast masses are echogenic and the majority of these lesions are benign. approximately, 0.5% of malignant breast lesions appear hyperechoic. The various benign pathologic entities that appear echogenic on US are lipoma, hematoma, seroma, fat necrosis, abscess, pseudoangiomatous stromal hyperplasia, galactocele, etc. The malignant diagnoses that may present as hyperechoic lesions on breast US are invasive ductal carcinoma, invasive lobular carcinoma, metastasis, lymphoma, and angiosarcoma. Echogenic breast masses need to be correlated with mammographic findings and clinical history. Lesions with worrisome features such as a spiculated margin, interval enlargement, interval vascularity, or association with suspicious microcalcifications on mammography require biopsy. In this article, we would like to present a pictorial review of patients who presented to our department with echogenic breast masses and were subsequently found to have various malignant as well as benign etiologies on histopathology.

Dual-color dual-hapten in situ hybridization (D-DISH) - Comparison with fluorescence in situ hybridization (FISH) for HER2/neu testing in breast cancer.

CONTEXT: HER2/neu testing in breast cancer is a mandate due to availability of trastuzumab, a monoclonal antibody targeted against this biomarker. Dual-color dual-hapten in situ hybridization (D-DISH) is a new test for assessment of HER2/neu gene overexpression on light microscopy. AIMS: This was a validation study for D-DISH in our laboratory and was conducted to study the concordance between fluorescence in situ hybridization (FISH) and D-DISH for HER2/neu testing in breast cancer. MATERIALS AND METHODS: In all, 150 cases of invasive breast carcinoma requested for FISH analysis were selected. Immunohistochemistry by Ventana PATHWAY anti-HER2/neu (4B5) antibody, FISH by ZytoLight SPEC ERBB2/CEN17 Dual Color Probe, and D-DISH using the Ventana INFORM HER2 Dual ISH DNA Probe Cocktail Assay was carried out. STATISTICAL ANALYSIS: Cohen's kappa coefficient was used to calculate concordance between FISH and D-DISH assays. The ratios and average number of signals were compared with Lin's concordance correlation coefficient. RESULTS: About 93.1% of the cases showed concordance between FISH and D-DISH results. Cohen's kappa correlation coefficient was 0.836, indicating almost perfect level of agreement. Lin's concordance correlation coefficient (ρc) showed moderate strength of agreement for HER2/chromosome 17 ratios between FISH and D-DISH assays (ρc 0.9452). As per the American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) 2018 updated guidelines, four of the cases that were nonamplified on FISH showed low-level amplification on D-DISH due to counting errors caused by faint signals or background dust. Genomic heterogeneity and larger red chromosome 17 signals on D-DISH led to discordance of the six cases amplified by FISH. D-DISH failure rate was 3.33%. CONCLUSION: Overall, D-DISH showed good concordance with FISH but needs expertise for reporting.

Fine needle aspiration cytology of epididymal nodules.

BACKGROUND: The incidence of non neoplastic lesions are much more common in epididymis. Clinically, epididymal nodules are easily accessible to fine needle aspiration cytology (FNAC) procedure. There are very few literature reports documenting the role of cytology in evaluation of epididymal nodules. Thus, we studied patients presenting with palpable epididymis nodules in the out patient department (OPD) from a tertiary care general hospital. AIM: This study is aimed to put forth the diagnostic utility of FNAC in palpable lesions of epididymis. MATERIALS AND METHODS: A total of 40 palpable epididymal nodules were aspirated as a routine OPD procedure as part of this study. Smears were fixed in isopropyl alcohol and air dried. In all the cases, wet fixed papanicoloau stained and air dried giemsa stained smears were studied. Zeihl Neelsen stain was performed in cases which yielded caseous aspirate. RESULTS: Except for two cases of adenomatoid tumor of epididymis all other lesions were nonneoplastic and included 14 cases (35%) of tuberculous granulomatous inflammation, 10 (25%) cystic nodules (9 spermatoceles and 1 encysted hydrocele), 5 (12.5%) of nonspecific inflammations, 3 (7.5%) filarial infection, 3 (7.5%) sperm granulomas and 3 (7.5%) adenomatous hyperplasia of rete testes. Except for the two tumors, one adenomatous hyperplasia and one tuberculous lesion, no other lesion was excised. Follow up and response to therapy was available in 78% patients and resolution indicated appropriateness of the diagnosis CONCLUSIONS: Thus, as most of the lesions in epididymis are non neoplastic responding to medical line of treatment and FNAC served to aid diagnosis of non specific inflammation and avoid surgical excision in most cases.

ALK+ anaplastic large cell lymphoma with cohesive, perivascular arrangements on cytology, mimicking a soft tissue sarcoma: a report of 2 cases.

BACKGROUND: An accurate recognition of a lymphoma at an extranodal site is essential to avoid unnecessary excisions. Fine needle aspiration cytology (FNAC) has been recognized as a useful tool in the primary diagnosis of soft tissue tumors. An anaplastic large cell lymphoma (ALCL), occurring in soft tissues, poses a diagnostic challenge. We present the cytomorphology of 2 cases of anaplastic lymphoma kinase (ALK)+ ALCL that displayed a perivascular arrangement, thereby mimicking a sarcoma. CASES: The patients were aged 16 and 9 years. While the former presented with multiple nodular soft tissue and bony lesions over the body, the latter complained of an axillary lump. FNAC smears in both cases showed pleomorphic cells, arranged in loosely cohesive groups around blood vessels and scattered singly, with prominent nucleoli and abundant, finely vacuolated cytoplasm. Interspersed were a few cells with embryoid nuclei. Differential diagnoses included a rhabdomyosarcoma and a lymphoma. On biopsy and immunohistochemistry, tumor cells were positive for vimentin, LCA, EMA, CD30 and ALK. CONCLUSION: ALCL should be considered in the differential diagnosis of pediatric soft tissue tumors, especially in cases with multifocal involvement. The presence of cohesive, perivascular arrangements on FNAC should not detract a cytologist for keeping this possibility in mind. Further, a careful search for the typical "hallmark" cells should be made.

Monophasic synovial sarcoma of tongue.

Synovial sarcoma is a well defined morphologic entity extensively researched in literature. Synovial sarcoma displays a wide spectrum of clinical presentations and histologic appearances that may give rise to diagnostic dilemmas. One such unusual site in the head and neck area is the tongue. We report a case of monophasic synovial sarcoma of the tongue in a 22-year-old male. Microscopically, this tumor mimicked a poorly differentiated carcinoma which is more common at this site though the patient was young for this type of tumor. On immunohistochemistry, neoplastic cells were positive for cytokeratin, vimentin, calponin, CD99 and bcl2. Molecular studies--viz. reverse transcriptase polymerase chain reaction revealed a SYT-SSX translocation clinching the diagnosis. This paper highlights the immunohistochemistry profile and SYT-SSX translocation which helped arrive at an accurate diagnosis only because the index of suspicion for a monophasic synovial sarcoma is high.

Solitary fibrous tumour: a diagnostic dilemma.

Solitary fibrous tumour (SFT) is a rare spindle cell neoplasm arising at pleural and extrapleural sites. Five cases of SFT diagnosed at our institution over a five year period were reviewed. Haematoxylin and eosin stained histological sections, immuno-histochemical markers including CD34 and electron microscopy were the different methods used to study these tumours. Three histological features were consistently observed in all the tumours: the tumours were composed of short spindle cells separated by dense collagen bands and arranged in alternate hypocellular and hypercellular areas. CD34 positivity was seen in all the cases. SFT's have been reported to behave in an unpredictable fashion and hence prolonged follow up is essential. Histology, CD34 positivity and electron microscopy are useful tools in diagnosing SFT. While the pleural tumours can be diagnosed based on histology, this must be substantiated by ancillary techniques in case of extrapleural tumours.

Fibromatosis-like carcinoma-an unusual phenotype of a metaplastic breast tumor associated with a micropapilloma.

BACKGROUND: Fibromatosis-like metaplastic carcinoma is a newly described metaplastic breast tumor, literature on which is still evolving. CASE PRESENTATION: A 77-year-old lady presented with a 2 x 2 cm mass with irregular margins in the upper and outer quadrant of left breast. Fine needle aspiration cytology (FNAC) from the lump was inconclusive. A lumpectomy was performed and sent for frozen section, which revealed presence of spindle cells showing mild atypia in a sclerotic stroma. The tumor cells revealed prominent infiltration into the adjacent fat. A differential diagnosis of a low-grade sarcoma vs. a metaplastic carcinoma, favoring the former, was offered. Final histology sections revealed an infiltrating tumor with predominant spindle cells in a collagenous background, simulating a fibromatosis. Adjacent to the tumor were foci of benign ductal hyperplasia and a micropapilloma. Immunohistochemistry (IHC) showed diffuse co-expression of epithelial markers i.e. cytokeratins (CK, HMWCK, CK7) and EMA along with a mesenchymal marker i.e. vimentin in the tumor cells. Myoepithelial markers (SMA and p63) showed focal positivity. A diagnosis of a low-grade fibromatosis-like carcinoma breast associated with a micropapilloma was formed. CONCLUSION: Fibromatosis-like carcinoma is a rare form of a metaplastic breast tumor. This diagnosis requires an index of suspicion while dealing with spindle cell breast tumors. The importance of making this diagnosis to facilitate an intra operative surgical planning is marred by diagnostic difficulties. In such cases, IHC is imperative in forming an objective diagnosis.

Comparative analysis of routine histology, immunohistochemistry, reverse transcriptase polymerase chain reaction, and fluorescence in situ hybridization in diagnosis of Ewing family of tumors.

CONTEXT: The Ewing family of tumors are often difficult to distinguish from other malignant small round cell tumors, but more than 90% have EWS-FLI1 chimeric transcript, which acts as a potential molecular diagnostic marker. OBJECTIVE: To do a comparative analysis of 32 cases with EWS-FLI1: Ewing family of tumors (n = 30), desmoplastic small round cell tumor (n = 1), and undifferentiated sarcoma (n = 1). DESIGN: The initial diagnosis was made on core biopsy (n = 22) and open biopsy (n = 4) specimens by using morphology and immunohistochemistry and on fine-needle aspiration cytology ([FNAC], n = 6) specimens. EWS-FLI1 was detected by reverse transcriptase polymerase chain reaction on all 32 fresh FNAC samples and by fluorescence in situ hybridization on 16 paraffin blocks. RESULTS: The 19 male and 13 female patients had bone (n = 19) or soft tissue (n = 13) tumors. Histologic groups were typical Ewing sarcoma (n = 15), atypical Ewing sarcoma (n = 4), Askin Rosai tumors (n = 5), desmoplastic small round cell tumor (n = 1), undifferentiated sarcoma (n = 1), and cases diagnosed as malignant small round cell tumors on FNAC (n = 6). All tumors except desmoplastic small round cell tumor and undifferentiated sarcoma were CD99 positive. EWS-FLI1 by reverse transcriptase polymerase chain reaction was noted in 15 cases of typical Ewing sarcoma, 4 cases of atypical Ewing sarcoma, 5 cases of Askin Rosai tumor, and no cases of desmoplastic small round cell tumor or undifferentiated sarcoma. With use of fluorescence in situ hybridization, EWS break was detected in 10 of 11 paraffin blocks used and was negative in desmoplastic small round cell tumor. CONCLUSIONS: The excellent correlation of routine histologic findings in Ewing family of tumors with results on immunohistochemistry and fluorescence in situ hybridization on archival material and reverse transcriptase polymerase chain reaction on fresh FNAC specimens underscores that the traditional observation on routine histologic examination is a time-tested tool. The diagnosis of Ewing family of tumors can be validated on archival material or fresh biopsy samples, including those obtained by FNAC.

Lipoid proteinosis in a 12-year-old child: a report from west India.

A 12-year-old male child born of non-consanguineous parents presented with multiple skin lesions, hoarseness of voice, and episodes of epilepsy since early childhood. The findings of characteristic beaded eyelid margins, patchy alopecia of the scalp, hoarseness of voice, and epilepsy were consistent with a rare clinical diagnosis, lipoid proteinosis. Skin biopsies obtained from representative skin lesions were subjected to histology and electron microscopy. Light microscopy demonstrated PAS-positive diastase-resistant material in the papillary dermis of skin. Ultrastructure revealed granulo-filamentary aspect of the accumulated material. Although this rare autosomal recessive disorder has been described in the literature, its occurrence is rare in India.

Rosette formation in osteosarcoma.

Rosette formation is a rare, recently reported variation in osteogenic sarcoma and is thought to be associated with a poor prognosis. We report two cases of rosette forming osteosarcoma, one with poor response and other with total necrosis following chemotherapy. Pathologists should be aware of rosette formation in osteosarcoma to avoid misdiagnosis as other rosette forming tumors of bone especially PNET/Ewings sarcoma. In our opinion rosettes in an osteosarcoma should be documented both from a differential diagnostic point of view and also to elucidate definitive prognostic implications.