Iranian Journal of Pathology最新文献

Background & objective: This study was designed to determine the prevalence of serotypes, virulence-associated genes, and antimicrobial resistance of Streptococcus agalactiae in pregnant volunteers attending a major maternity hospital in Iran.

Methods: The virulence determinants and antimicrobial resistance profiles of 270 Group B streptococcus (GBS) samples were assessed in the adult participants. The prevalence of GBS serotypes, virulence-associated genes, and antimicrobial resistance of the isolates was determined.

Results: The GBS prevalence in the vaginal, rectal, and urinal carrier rates were 8.9%, 4.44%, and 4.44%, respectively, with no concomitant colonization. The serotypes Ia, Ib, and II were at a 1:2:1 ratio. The rectal isolates, harboring CylE, lmb, and bca genes, were of serotype Ia, susceptible to vancomycin. The serotype Ib from urine samples carrying three distinct virulence genes was susceptible to Ampicillin. In comparison, the same serotype with two virulence genes of CylE and lmb exhibited sensitivity to both Ampicillin and Ceftriaxone. The vaginal isolates belonged to serotype II with the CylE gene or serotype Ib with CylE and lmb genes. These isolates harboring the CylE gene were resistant to Cefotaxime. The overall antibiotic susceptibility range was 12.5-56.25%.

Conclusion: The findings broaden our understanding of the pathogenicity of the prevailing GBS colonization and predict different clinical outcomes.

Background & objective: Clear cell carcinoma (CCC) is an uncommon histopathologic subtype of ovarian and endometrial carcinoma. Due to the morphologic overlapping with other subtypes of ovarian and endometrial carcinomas, an accurate diagnosis is crucial.

Methods: In this study, 31 cases of ovarian clear cell carcinoma (OCCC), 28 endometrial clear cell carcinoma (ECCC), and 80 non-CCC subtypes (33 high-grade serous carcinomas of the ovary, 2 low-grade serous carcinomas, 10 ovarian endometrioid, 3 serous carcinomas and 29 endometrioid carcinomas of the endometrium) were investigated for immunohistochemical expression of AMACR. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for the distinction of OCCC and ECCC from other histopathologic subtypes were calculated.

Results: Positive AMACR staining was seen in 18 OCCCs (58%) and 10 ECCCs (35.7%). In the non-clear cell group, 44 cases of ovarian (98%) and 25 cases of endometrial carcinoma (78%) showed negative results. Only one case of ovarian endometrioid carcinoma and 7 cases (22%) of endometrial endometrioid carcinomas revealed a positive reaction (P<0.05). Collectively, sensitivity, specificity, PPV, and NPV of AMACR expression, for the diagnosis of OCCC were calculated as 58%, 98%, 94.7%, and 77.2%, respectively. The sensitivity, specificity, PPV, and NPV were shown to be as 35.7%, 78.1%, 58.8%, and 58.1%, respectively in the endometrium.

Conclusion: AMACR may be a highly specific immunohistochemical marker for the distinction of serous and clear cell carcinoma. A small percentage of endometrioid carcinoma may show positive staining. The sensitivity of this marker may not be higher than the other well-known Napsin-A IHC marker.

Background & objective: Head and Neck Squamous Cell Carcinoma (HNSCC) is a highly frequent malignancy worldwide and is also the leading cause of death. The prognosis for individuals with HNSCC remains dismal, with a five-year survival rate of less than 50%. The novel anti-PD-L1 immunotherapy is found to be promising, and immunohistochemistry (IHC) has been established as a reliable method for patient stratification. We intend to evaluate the prognostic significance of the expression of programmed death ligand-1 (PD-L1) in HNSCC and determine its association with clinicopathological variables.

Methods: A total of 50 cases of biopsy-confirmed HNSCC were studied in a tertiary hospital between Dec 2020 and June 2022. The specimens were tested for PD-L1 IHC expression with antibody clone CAL-10 (Biocare) and scored by Combined Positive Score (CPS). The association between PD-L1 expression and clinicopathological variables was evaluated.

Results: PD-L1 was positive in 92% of the cases, and a significant association (P= 0.024) was seen between PD-L1 expression and tumor-infiltrating lymphocytes (TILs). PD-L1 did not show any significant association with patient demographics, tumor site, grade, or stage.

Conclusion: In the present study, evaluation of the immunohistochemical expression of PD-L1 on the tumor cells and TILs in HNSCC revealed a high prevalence of PD-L1 expression. PD-L1 IHC studies for patient selection for immunotherapy would be a promising technique. Frequent PD-L1 expression in tumors with significant TILs may be useful in identifying patients who may benefit from anti-PD-1/PD-L1 therapy.

Background & objective: Epithelial ovarian cancer (EOC) is the most prevalent type of ovarian cancer. Previous studies have elucidated different pathways for the progression of this malignancy. The mutation in the B-Raf proto-oncogene, serine/threonine kinase (BRAF) gene, a member of the MAPK/ERK signaling pathway, plays a role in the development of EOC. The current study aimed to determine the frequency of the BRAF V600E mutation in ovarian serous and mucinous tumors, including borderline and carcinoma subtypes.

Methods: A total of 57 formalin-fixed paraffin-embedded samples, including serous borderline tumors (SBTs), low-grade serous carcinomas (LGSCs), high-grade serous carcinomas (HGSCs), mucinous borderline tumors (MBTs), and mucinous carcinomas, and 57 normal ovarian tissues were collected. The BRAF V600E mutation was analyzed using polymerase chain reaction (PCR) and sequencing.

Results: While 40% of the SBT harbor BRAF mutation, we found no BRAF mutation in the invasive serous carcinoma (P=0.017). Also, there was only 1 BRAF mutation in MBT and no mutation in mucinous carcinomas. In addition, we found no mutation in the control group.

Conclusion: The BRAF mutation is most frequent in borderline tumors but not in invasive serous carcinomas. It seems that 2 different pathways exist for the development of ovarian epithelial neoplasms: one for borderline tumors and the other for high-grade invasive carcinomas. Our study supports this hypothesis. The BRAF mutation is rare in mucinous neoplasms.

Xanthomas are characterized by the presence of foamy lipid-laden macrophages. The gastrointestinal tract is an uncommon site for xanthoma, with the stomach being the most favored location. They have been associated with various premalignant and malignant conditions of the stomach. We present a case of a 21-year-old female patient with dyspepsia of 4 months duration. Her lipid profile was mildly altered. On upper gastrointestinal endoscopy, multiple discrete yellow patches were found in the antrum, diagnosed as gastric xanthoma on microscopy. Various published literature has emphasized the frequent association of gastric xanthomas with gastritis, gastric atrophy, intestinal metaplasia, and gastric cancer. Hence, there is a necessity for early recognition, treatment of any coexistent pathology, and close clinical follow-up.

Background & objective: Lymphovascular tumoral invasion is a typical histopathological feature of gastric carcinomas and supports the recognition of high-risk patients for the recurrence. We aimed to study CD31 expression in diverse subtypes of gastric carcinomas and to show its association with the histopathologic findings of the carcinoma to assess the prognosis.

Methods: This cross-sectional study was conducted on 40 established patients with gastric adenocarcinoma from radical gastrectomy. The patients were classified according to the pathology assessments. Tumoral tissues were assessed by immunohistochemical staining for CD31 expression. Malignant behavior was estimated by histopathological evaluations.

Results: CD31 positivity was described in 23 (57.5%) of all evaluated patients. In assessment of CD31 expression and tumor features presented, no significant association between the CD31 expression and patients' age, sex, tumor site, size, grade and stage, subtypes of carcinoma, perineural invasion, and also lymphovascular invasion was found. (P>0.05).

Conclusion: Lymphovascular invasion may make valuable additional evidence and may be useful to detect gastric carcinoma patients at high risk for recurrence, who could be candidates for more supplementary therapies. However, in our study, CD31 expression did not show any association with the aggressive histopathologic features of this tumor.

Background & objective: Tissue microarray (TMA) is a method of harvesting small tissue cores from a number of donor paraffin tissue blocks and arraying them in a recipient paraffin block. It has numerous advantages and applications but is expensive. This study aimed to develop a simple yet efficient method of manual, small-format TMA block construction.

Methods: Disposable skin punch biopsy needles were used to manually core out 4-mm cylinders from the archival donor blocks comprising tissue from 60 thyroidectomy specimens. These cores were oriented in the embedding cassette in accordance with the grid design. The molten wax was slowly dispensed and allowed to be set. Sectioning, mounting, and hematoxylin and eosin (H&E) staining were performed by a conventional method. Immunohistochemical studies, using HBME-1, CK19, and S100 antibodies, were also performed on these tissue array sections.

Results: There was no core loss during processing. Technical issues like core tilt and floatation were easily tackled. Morphological identification, histological typing, and immunohistochemical analysis could be satisfactorily performed in these TMA sections. Donor blocks did not break after punching.

Conclusion: This TMA construction method is simple, feasible, easily reproducible, and time-saving. It can serve as an excellent cost-effective alternative for resource-poor laboratories for carrying out immunohistochemical studies.