ABSTRACT
Background: Mutations in ROS1, ALK, and MET genes are targetable alterations in non-small cell lung cancer (NSCLC). They can be evaluated by different techniques, most commonly fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC). Methods: We explored the prevalence of ROS1, ALK, MET mutations, discuss clinicopathological associations and FISH signal patterns on 413 consecutive cases of EGFR negative lung carcinoma from March 2016 to April 2017 using FISH for ALK, ROS1, and MET along with ALK (D5F3) IHC. Results: ROS1 gene rearrangement, ALK positivity (IHC and/or FISH), and MET amplification were seen in 18/358 (5%) cases, 76/392 cases (19.4%), and 10/370 (2.7%) cases, respectively. ALK FISH and ALK IHC were positive in 51/300 (17%) and 58/330 cases (17.57%), respectively, while 8/330 (2.4%) cases were ALK IHC “equivocal” of which 3/8 (37.5%) were ALK FISH positive. Of ALK FISH and IHC co-tested cases, 43/238 (18.07%) cases were positive by both techniques, while 15/43 (34.88%) of ALK positive cases showed discordant ALK FISH and IHC results. All ROS1 rearranged and MET amplified cases were adenocarcinoma. Signet ring cell histology was associated with 78.57% likelihood of being either ALK or ROS1 positive. Genomic heterogeneity was seen in 30% of MET amplified cases. Conclusions: ALK/ROS1/MET gene alterations were found in 25.18% of NSCLC cases. An ALK IHC “equivocal” interpretation category should be incorporated into practice. Atypical patterns of ROS1 and genomic heterogeneity need to be evaluated further for any clinical relevance.
ABSTRACT
Background: Granulosa cell tumor of testis is a rare tumor accounting for less than 4% of adult testicular tumors though they account for nearly 30% of childhood testicular tumors. Due to the rarity of these tumors, exact etiology, pathogenesis, prognostic factors and best treatment approach are not well known. The molecular events in pathogenesis of these stromal tumors have begun to unravel and these developments put forth a reasonable and scientifi c explanation for the association of these tumors with developmental anomalies like undescended testis. However, many questions remain unanswered. Materials and Methods: We performed a retrospective analysis of clinicopathological features of all Granulosa Cell Tumors of testis from our archives in addition to an extensive literature search using PUBMED with the key words “Granulosa Cell Tumor, testis”. Results: We found six cases in our archives, two of which were of juvenile type and four of adult type. One out of these six cases presented with metastases. All cases underwent radical orchidectomy. Morphology and immunohistochemistry were classical in all cases and there was no diagnostic dilemma. Literature search revealed 63 cases of testicular Granulosa Cell Tumor in addition to highlighting the similarities in the biology and the dissimilarities in the clinical behavior as compared to ovarian Granulosa Cell Tumor. Conclusion: Testicular Granulosa Cell Tumor is a rare tumor, which although histologically similar to its ovarian counterpart, differs in clinical behavior. Further detailed investigations are needed to reveal the mystery behind the differing clinical behavior despite histological and immunohistochemical similarity between the testicular and ovarian Granulosa Cell Tumors.