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Our study lends support to the hypothesis that infection of HPV-16/-18 may play an important role in the development of nonfamilial form of RB in children in India.

Histone deacetylase 6 (HDAC6) is an alpha (α)-tubulin deacetylase and its over-expression has been demonstrated to promote chemotactic cell movement. Motility in sperm is driven by the flagella, the cytoskeletal structure comprising the microtubules, which are heterodimers of α- and β-tubulins. We have hypothesized that HDAC6, by virtue of being an α-tubulin deacetylase, might modulate sperm motility. However, the presence of HDAC6 on sperm has hitherto not been reported. In this study, we have demonstrated, for the first time, the presence of HDAC6 transcript and protein in the testicular and caudal sperm of rat. We have observed a significantly overlapping expression of HDAC6 with acetyl α-tubulin (Ac α-tubulin) in the mid-piece and principal piece of sperm flagella, and the co-precipitation of α-tubulin and Ac α-tubulin together with HDAC6 and vice versa in sperm lysates. This indicates that HDAC6 interacts with α-tubulin. The HDAC6 activity of sperm, sperm motility and status of Ac α-tubulin investigated in the presence of HDAC inhibitors Trichostatin A, Tubastatin A and sodium butyrate demonstrate that HDAC6 in sperm is catalytically active and that inhibitors of HDAC6 increase acetylation and restrict sperm motility. Thus, we show that (1) active HDAC6 enzyme is present in sperm, (2) HDAC6 in sperm is able to deacetylate α-tubulin, (3) inhibition of HDAC6 results in increased Ac α-tubulin expression and (4) HDAC6 inhibition affects sperm motility. This evidence suggests that HDAC6 is involved in modulating sperm movement.

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Solitary fibrous tumor (SFT) has been rarely documented in the female genital tract. Until now, only 5 such cases have been reported in the vagina. A 40-yr-old referred to us with a history of antitubercular treatment and intra-abdominal adhesions; for which she previously underwent laparoscopic. Subsequently, she developed a vaginal mass, which appeared as a complex cyst on ultrasonogram. Histopathologic examination of the excised mass revealed a cellular spindle cell tumor with collagenous deposition in the stroma. The tumor cells were composed of oval to spindle shaped nuclei and were arranged in a diffuse, as well as in a focally, hemangiopercytomatous pattern. There were no significant mitotic figures or tumor necrosis. By immunohistochemistry, the tumor cells showed patchy positivity for CD34 and diffuse intranuclear positivity for STAT6, along with cytoplasmic positivity for MIC2 and BCL2. Few cells were estrogen receptor positive. MIB1/Ki67 highlighted 2% to 3% tumor nuclei (low). Diagnosis of a SFT was rendered. Subsequently, the tumor was subjected to molecular analysis, by reverse transcriptase-polymerase chain reaction and sequencing, which revealed presence of NAB2ex4-STAT6ex2 fusion transcript. This case constitutes the first case of a vaginal SFT confirmed by STAT6 immunostaining and NAB2-STAT6 fusion. It exemplifies the role of specific immunohistochemical markers, such as STAT6 in differentiating a SFT from various other spindle cell tumors occurring in this location. Literature review of similar reported cases and treatment implications in such cases are discussed.

Background: The exon 11 KIT mutant gastrointestinal stromal tumors (GIST) is a heterogeneous cohort with variable biological behavior based on different mutational subtypes. Methods:Patients with histologically proven GIST with KIT exon 11 mutations were selected from a prospectively maintained database, and evaluated for clinical characteristics and event free survival (EFS). Patients were divided into mutations upstream to codon 557 (G1), mutations involving codon 557-558 (G2) and mutation downstream to codon 558 (G3).Results: A total of 90 patients satisfied the inclusion criteria for study. Substitutions, indels and duplications were seen in 23 patients. Deletions were seen in 67 patients, of which 44 patients had large deletions (>6 base pairs), while 23 has small deletions (<6 base pairs). Complex mutations were seen in 15 patients. G2 mutations were noted in 33 patients, while G1 and G3 mutations were seen 32 and 25 patients respectively. With a median follow-up of 26 months, estimated median EFS for the entire cohort was 55 months. The G2 cohort had an inferior EFS compared to the G1 and G3 cohorts (46 vs. 55 months), but this did not achieve statistical significance (univariate analysis: P=0.075). On multivariate analysis, patients undergoing radical intent surgery vs. no surgery (58 vs. 55 months; P=0.005) and G1 or G3 vs. G2 cohort (P=0.058) showed trend towards improved EFS. Conclusions:In patients with GIST exon 11 codon 557-558 mutation subset there is a trend towards an inferior survival even when treated with imatinib mesylate (IM).

Synovial sarcoma is a high-grade, soft tissue sarcoma that is relatively chemosensitive. Its exact diagnosis is crucial, including differentiation from its closest diagnostic mimic, ie, Ewing sarcoma, in view of different treatment options, including chemotherapy regimens, for both these tumors. A 15-year-old girl presented with a recurrent soft tissue mass in her right popliteal region, which was diagnosed as Ewing sarcoma, based on positive immunoexpression of MIC2/CD99, Fli1 and negative expression of LCA and desmin. During her metastatic "work-up", a popliteal lymph node was identified, which was aspirated and examined. Fine needle aspiration cytology smears showed singly scattered and loose, cohesive clusters of cells containing round to polygonal, to short spindle-shaped nuclei with prominent nuclei, and moderate to abundant cytoplasm, including several "rhabdoid" cells. These features prompted a review of the biopsy of the recurrent tumor, and additional immunohistochemical stains, which revealed positive co-expression of pan cytokeratin (AE1/AE3), epithelial membrane antigen (EMA), along with a characteristic variable staining pattern of INI11/SMARCB1. Subsequently, by fluorescent in situ hybridization (FISH) technique, performed on the paraffin section of the recurrent tumor, 100% tumor nuclei displayed SS18 rearrangement, while none of the tumor cells displayed EWSR1 rearrangement. Diagnosis of poorly differentiated SS with "rhabdoid" features was confirmed. This constitutes as the first case, describing cytopathologic features of a poorly differentiated SS with "rhabdoid" features, initially misdiagnosed as a Ewing sarcoma, on biopsy and confirmed as SS by FISH technique. The diagnostic and treatment implications in this case are discussed herewith. Diagn. Cytopathol. 2017;45:662-667. © 2017 Wiley Periodicals, Inc.