WHICH EVOLUTIONARY FORCES DICTATE CODON USAGE IN HUMAN TESTIS SPECIFIC GENES?

Objective: Unequal usage of synonymous codons encoding an amino acid is termed as codon usage bias. Synonymous codon usage bias is an inevitable phenomenon in organismic taxa across the three domains of life, i.e. plants, animals and microbes. Here we report the codon usage pattern in human testis-specific genes found in Y chromosome. Testis-specific genes are associated with several dysfunctions, such as gonadal sex reversion, infertility, gonadoblastoma and non-syndromic hearing impairment.Methods: We used bioinformatics approaches to analyze codon usage bias in human testis-specific genesResults: Highly significant negative correlation was found between ICDI and tAI (r=-0.939**, p<0.01). Moreover, highly significant positive correlation between A% and A3% (r =0.774*, p<0.05), T and T3% (r=0.894**, p<0.01), GC% and GC3% (r = 0.897**, p<0.01) suggest that mutation pressure played an important role in codon usage pattern of these genes. However, significant positive correlation between G and G3 % (r =0.936**, p<0.01), G and C3 (r=0.557, p>0.05) but negative correlation between GC and T3 % (r=-0.960**, p<0.01) indicate the role of natural selection on codon bias. Variation of codon usage pattern was also evident in different genes from principal component analysis (PCA).Conclusion: Codon usage bias in human testis-specific genes is low. These genes are rich in GC content. Both natural selection and mutation pressure affect the codon usage bias in these genes.Keywords: Codon usage bias, Mutation pressure, Natural selectio

Recurrent spindle cell lipoma mimicking myofibroblastic tumor with myxoid changes: Cytological diagnostic dilemma

Spindle cell lipoma (SCL) is an uncommon subtype of benign lipomatous neoplasms with a rare probability of the local recurrence.Correct cytological diagnosis is essential for the patient management. Surgical excision is the treatment of choice. Sometimes,it gets very difficult to reach a correct cytological diagnosis without a histomorphology or immunology. We are reporting a caseof recurrent SCL in an adult male and emphasise on distinguishing cytological features for a correct and accurate diagnosis oncytomorphology. The correct cytological diagnosis of recurrent SCL is essential to distinguish it from malignant lipomatous andother soft tissue tumors

Evaluation of Sentinel Node Biopsy in Locally Advanced Breast Cancer Patients Who Become Clinically Node-Negative after Neoadjuvant Chemotherapy: A Preliminary Study

Introduction. Controversy continues over the appropriate timing of sentinel lymph node (SLN) biopsy in locally advanced breast cancer (LABC) patients receiving neoadjuvant chemotherapy. We evaluated the feasibility and accuracy of SLN biopsy in LABC patients with cytology-proven axillary nodal metastasis who become clinically node-negative after neoadjuvant chemotherapy. Materials. 30 consecutive patients with LABC, who had become clinically node-negative after 3 cycles of neoadjuvant chemotherapy, were included in the study. They were then subjected to SLN biopsy, axillary lymph node dissection, and breast surgery. Results. Sentinel nodes were successfully identified in 26 of the 30 patients, resulting in an identification rate of 86.67%, sensitivity of 83.33%, false negative rate of 20%, negative predictive value of 72.73%, and an overall accuracy of 88.46%. No complications were observed as a result of dye injection. Conclusions. SLN biopsy is feasible and safe in LABC patients with cytology-positive nodes who become clinically node-negative after neoadjuvant chemotherapy. Our accuracy rate, identification rate, and false negative rate are comparable to those in node-negative LABC patients. SLN biopsy as a therapeutic option in LABC after neoadjuvant chemotherapy is a promising option which should be further investigated

Malakoplakia of bone: A case report

BACKGROUND: Malakoplakia is an uncommon but distinctive granulomatous disease, characterized by an accumulation of histiocytes or Von Hansemann cells containing intracytoplasmic, laminated Michaelis- Gutmann bodies. CASE: A 3-year-old male presented with a tender swelling in the left gluteal region that had been present for one month. Smears made from a fine needle aspirate showed large histiocytic cells containing intracytoplasmic, basophilic, laminated, targetoid Michaelis-Gutmann bodies resembling Von Hansemann cells in malakoplakia. Histopathology confirmed the diagnosis of malakoplakia of bone. CONCLUSION: This case, histologically proven to be malakoplakia, demonstrated regression of the lesion following therapy. The characteristic cytologic features and presence of Von Hansemann cells may in themselves be diagnostic and obviate the need for biopsy

Evaluation of the efficacy of post prostatic massage urine cytology in diagnosis of various prostatic lesions with cytohistological and clinical correlation

Background: Elderly men are at high risk of various prostatic diseases carrying high morbidity and mortality rates. For screening large populations, there is a need for a simple, reliable, and noninvasive test with high sensitivity and specificity. Exfoliated prostatic cancer cells can be harvested by prostatic massage and subjected to cytologic examination and molecular tests. Aims: This study was undertaken to evaluate the morphology of various prostatic lesions on post prostatic massage urine cytology and correlate cytologic, histologic, and clinical findings. It was further proposed to establish the diagnostic accuracy of post prostatic massage urine cytology in different prostatic lesions. Materials and Methods: Totally, 100 cases including 50 cases each from study group and control group were subjected to post prostatic massage urine cytology and correlated with clinical and histological findings. Results: Five out of 50 cases were diagnosed as prostatic carcinoma, of which 60% were clinically detected. Diagnostic accuracy by histology and cytology independently was 80%, and 20% remained false negative by each technique. On combining both the techniques, diagnostic accuracy was 100%. For nine cases each of prostatitis and nodular hyperplasia diagnosed clinically, the diagnostic accuracy by cytology was 100 and 66.6%, respectively. 62% (31) cases were diagnosed as nodular hyperplasia including 22 (44%) cases of nodular hyperplasia with prostatitis. Conclusion: Collection of urinary specimens after prostatic massage provides adequate samples for cytological examination and carries great importance in establishing the preoperative morphologic diagnosis in cases of malignancy, prostatitis, and prostatic calculi

Diagnostic utility of ki67 and p53 immunostaining on solitary thyroid nodule - A cytohistological and radionuclide scintigraphic study

Background: For management of thyroid nodules, distinction between benign and malignant tumors is essential. Present study was undertaken to differentiate between benign and malignant lesions by using Ki-67 and p53 immunostaining and radionuclide perfusion scan. Materials and Methods: Study comprised of 25 prospective and 25 retrospective cases of solitary thyroid nodules. Fine needle aspiration was done on 25 prospective cases, which was correlated with histopathological diagnosis in 24 surgically excised cases. Immunostaining for p53 and Ki-67 was put on histopathological sections of 25 retrospective and 24 prospective cases. Radionuclide perfusion scan was performed and vascularity patterns were compared with their pathological nature to differentiate between benign and malignant nodule. Results: Cytohistological correlation was present in 80% of cases. On immunostaining, significant difference in mean value of Ki67 positivity was found between benign and malignant nodules (P < 0.05). On p53 immunostaining significant difference was observed in counts of benign and malignant lesions (P = 0.037). On radionuclide perfusion scan mean of difference between maximum and minimum perfusion activity between benign and malignant nodules was found to be statistically significant (P = 0.04), however there was no correlation between perfusion patterns and antigenic characteristics. Conclusions: P53 and Ki-67 immunostaining along with radionuclide perfusion scan appears to be useful tools to differentiate between benign and malignant lesions in solitary thyroid nodule; however, more studies are needed to confirm this observation

Myxopapillary ependymoma: Lesser known cytomorphologic features

Myxopapillary ependymoma (MPE) is a rare and distinctive tumor which occurs in the sacrococcygeal area of young adults and children, often intradural in location. Histopathologic features have been well-described in the literature whereas cytological findings have been sporadically reported by various authors mainly as case reports. We report the features of a primary sacrococcygeal MPE on aspirate cytology in a 45-year-old female. Cytology smears displayed a papillary pattern with the presence of fibrovascular cores, rimmed by cuboidal to columnar cells sending fibrillary cytoplasmic processes forming pseudorosettes along with the presence of hyaline globules, and myxoid material. Intranuclear inclusions, nuclear grooves, cytologic atypia or mitotic activity was not evident, in this case. MPEs need to be differentiated from the other tumors occurring in this location which may also show myxoid material and papillary fronds. Hence, the recognition of the characteristic cytologic features plays an important role in establishing a preoperative diagnosis

A cytohistological study of Ki-67 expression in ovarian tumors

Background and Objective: The study was conducted to evaluate the diagnostic accuracy of imprint cytology in ovarian neoplasms, and to investigate the biological significance of Ki-67 antigen expression in benign and malignant ovarian tumors and correlate it with histological type, grade, and stage of malignant tumor. Materials and Methods: A total of 50 cases including 25 prospective and 25 retrospective cases were studied. Imprint cytology was performed on 25 ovarian tumors and compared with histopathological diagnosis. Ki-67 immunohistochemistry was performed on all 50 cases. Results: On immunohistochemistry, benign tumors had a mean Ki-67 index of 3.2 ± 3.7 while malignant tumors had a mean Ki-67 index of 33.1 ± 16.7, the difference being statistically significant. Significant correlation was observed between the Ki-67 index and stage of the tumor; however, there was no correlation between the grade of differentiation and histological type of tumor with the Ki-67 index. Conclusions: In the present study, the Ki-67 index was higher in advanced stage tumors; hence a higher Ki-67 index points toward the aggressive behavior and poorer clinical outcomes

Yolk sac tumor of cryptorchid testis diagnosed by fine needle aspiration cytology

Yolk sac tumor is the most common germ cell tumor in infants and children. Majority of them arise in the gonads. Yolk sac tumor of undescended testis has been rarely diagnosed. We present a case of yolk sac tumor in right undescended testis in a 2-year-old child primarily diagnosed by fine needle aspiration cytology