ABSTRACT
BACKGROUND: : Molecular confirmation of histologic diagnosis has become mandatory for the diagnosis of Ewing sarcoma family of tumors (ESFT). AIM: To validate the diagnosis made by morphology and immunohistochemistry (IHC) by fluorescence in-situ hybridization (FISH) for EWSR1 rearrangement on formalin fixed paraffin embedded (FFPE) tissues. Settings and design: A retrospective and prospective observational study. Material and methods: All patients who had FISH studies for EWSR1 rearrangement for small round cell tumors during 10 years period were included. Demographic, clinical and radiological details were obtained from medical records. Morphology was reviewed with IHC by CD99, FLI1 and others. FISH studies were performed using the break apart probe. Additional molecular studies and IHC were done to resolve the diagnosis in EWSR1 rearranged tumors. Final diagnosis was made by integrating clinical, morphology, IHC and molecular features. RESULTS: There were 81 patients (M: F 45:36, median age 21 years) with 32 skeletal and 49 extra skeletal tumors. CD 99 was positive in 94.52%. FISH for EWSR1 were positive in 59, negative in 13 and failed in 9. The final diagnosis was made as ESFT in 67, angiomatoid fibrous histiocytoma in 3, desmoplastic small round cell tumor in 3, myxoid chondrosarcoma in 2, unclassified in one, synovial sarcoma in 3, and one each of lymphoma and small cell neuroendocrine carcinoma. FISH was positive for ESFT in 89.83% of EWSR1 rearranged tumors. FISH validated the diagnosis made on IHC in 79.10%. FISH resolved the diagnosis in 1.49% CD99 negative tumors. CONCLUSION: FISH is a reliable ancillary technique for the diagnosis of ESFT on FFPE tissues.
Subject(s)
In Situ Hybridization, Fluorescence/methods , RNA-Binding Protein EWS/genetics , Sarcoma, Ewing/diagnosis , Sarcoma, Ewing/genetics , Tertiary Healthcare/statistics & numerical data , Adolescent , Adult , Aged , Biomarkers, Tumor/genetics , Child , Child, Preschool , Female , Humans , Immunohistochemistry , Infant , Male , Middle Aged , Prospective Studies , Retrospective Studies , Translocation, Genetic , Young AdultABSTRACT
OBJECTIVE: The objective of this study is to retrospectively evaluate follicular variant of papillary thyroid carcinoma (FVPTC) and reclassify encapsulated FVPTC as noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) according to the criteria proposed by The Endocrine Pathology Society working group in 2015 to correlate with outcome. MATERIALS AND METHODS: Retrospective review of case records of all patients diagnosed as carcinoma of thyroid between 2015 and 2016 was done for the histologic subtype. Gross and microscopic features on resected specimens of FVPTC were reviewed and subtyped as invasive and encapsulated based on capsular/vascular invasion; the encapsulated forms were further studied for size, number, follicular architecture, nuclear features, presence of psammoma bodies, stromal fibrosis, necrosis, mitoses, and lymph node status. RESULTS: Out of the 383 patients with thyroid carcinomas in the study period, 349 were PTC which included 106 FVPTC. Thirty-three patients fulfilled the criteria to be labeled as NIFTP. Total thyroidectomy was performed in 8 patients and hemithyroidectomy in 25 patients. Lymph node dissection along with total thyroidectomy was done in 3 and completion thyroidectomy following hemithyroidectomy was done in 9. There were 29 single and 4 multiple lesions with size varying from 0.2 to 7 cm including 5 lesions measuring <1 cm. The involvement was confined to one lobe in 31 and both lobes in 2 specimens. Patients are on follow-up with no recurrence till date. CONCLUSION: Thyroid carcinomas currently diagnosed as FVPTC should be evaluated for criteria of NIFTP to avoid overtreatment as they have an indolent behavior.