Disseminated mycobacterium genavense infection with central nervous system involvement in an HIV patient: a case report and literature review.

BACKGROUND: Immunodeficient patients, particularly HIV patients, are at risk of opportunistic infections. Nontuberculous mycobacteria can cause severe complications in immunodeficient patients. CASE PRESENTATION: We describe a 57-year-old HIV patient, primarily presented with coughs and constitutional symptoms, with a unique Mycobacterium genavense abdominal, pulmonary, and central nervous system infection, accompanied by intracranial masses. CONCLUSION: The diagnosis of NTM, including M. genavense, must always be considered by clinicians in immunodeficient patients, especially those with HIV, who have a compromised immune system.

Utility of AMACR immunohistochemical staining in differentiating Arias-Stella reaction from clear cell carcinoma of ovary and endometrium.

BACKGROUND: The Arias-Stella reaction is a hormone-related atypical endometrial change characterized by cytomegaly, nuclear enlargement, and hyperchromasia of endometrial glands; typically associated with intrauterine or extrauterine pregnancies or with gestational trophoblastic disease. Although differentiating the Arias-Stella reaction (ASR) from clear cell carcinoma (CCC) of the endometrium is usually straightforward, but differentiating ASR might be difficult if it occurs outside the setting of pregnancy, in extra-uterine sites or in older patients. The aim of this study was to determine whether P504S/Alpha Methyacyl CoA racemase (AMACR) immunohistochemical (IHC) staining can be used to differentiate ASR from CCC. METHODS: Fifty endometrial ASR and 57 CCC samples were assessed by IHC staining with antibody for AMACR. The immunoreactive score (IRS) was based on total intensity score (no staining to strong scored as 0-3) + percentage score (0-100% categorized as 0-3) ranged from 0 to 6. Positive expression was considered as a total IRS exceeding 2. RESULTS: The mean age of the patients in the ASR was significantly lower than that of CCC (33.34 ± 6.36 and 57.81 ± 11.64 years old, respectively, p < 0.001). The overall AMACR staining score was significantly higher among CCC compared to ASR groups (p = 0.003). The positive and negative predictive values for AMACR expression in detecting CCC from ASR were 81.1% and 57%, respectively. CONCLUSION: IHC staining for AMACR can be helpful and a member of discriminatory IHC panel when clinical or histologic features cannot facilitate the differential diagnosis between ASR versus CCC.

HER-2 overexpression in female genital tract clear cell carcinomas: Evaluation of different scoring guidelines, clinicopathological features and prognostic impact.

BACKGROUND: Clear cell carcinoma (CCC) is a rare high-grade adenocarcinoma associated with poor response to platinum-based chemotherapy agents in the female genital tract. Human epidermal growth factor receptor 2 (HER2) overexpression is routinely used as a biomarker for targeted therapy in breast and gastric carcinomas, but its role in CCC remains unclear. METHODS: In this study, HER2 overexpression was evaluated by immunohistochemistry (IHC) using College of American Pathologists (CAP) HER2 scoring guidelines for breast and endometrial serous carcinoma (ESC) on tissue microarray blocks. In equivocal and positive cases, fluorescence in situ hybridization (FISH) was performed. IHC score 3, and all amplified cases on FISH test were considered positive. RESULTS: Thirty-six cases of ovarian (OCCC), 36 endometrial (ECCC), and 2 cervical CCC were included. According to ESC and breast scoring guidelines, 20 % and 15.1 % of ECCC and 14.7 % and 6 % of OCCC were HER2 positive, respectively. Both cases of cervical CCC were negative. Scoring based on breast carcinoma guideline showed higher concordance (100 %) with gene amplification results, in comparison with ESC guideline (82.7 %). On multivariate survival analysis, HER2 positive ECCC and OCCC (based on ESC scoring methods) had significantly lower overall and disease-free survivals (OS, DFS) (P < 0.05). CONCLUSION: HER2 immunoscoring based on ESC guideline can yield a higher sensitivity with relevant clinical and prognostic features in OCCC and ECCC. HER2 can be considered a potential biomarker for targeted therapy and future clinical trials.

Expression of PD1 and PDL1 as immune-checkpoint inhibitors in mantle cell lymphoma.

BACKGROUND: Mantle cell lymphoma (MCL) has remained incurable in most patients. The expression of PD-L1 as a prognostic and predictive marker has not been fully evaluated in MCL. The current study aimed to determine PD-1/PD-L1 expression in MCL specimens and its significance as an immune check point inhibitor. METHODS: This retrospective study was conducted on the formalin-fixed paraffin-embedded blocks of 79 confirmed MCL patients based on immunohistochemistry (IHC). The IHC method was used to stain patient samples for PD1 and PDL1. Positive PD-1/PD-L1 expression was defined as moderate to strong or memberanous or memberanous/cytoplasmic staining in at least 5% of tumor and/or 20% of associated immune cells. Tumor aggressiveness was determined based on Ki67 and variant. RESULTS: The mean age of the patients was 60.08 ± 10.78 years old. Majority of the patients were male. The prevalence of aggressive tumor was 25%. Positive PD1 and PDL1 expression were identified in 12 (15.0%) and 3 (3.8%) of tumor cells, respectively. PD1 and PDL1 were positive in zero (0%) and 7 (8.9%) of background cells, respectively. There was no significant difference in terms of study parameters between positive and negative groups for both PD1 and PDL1 proteins. PD1 tumor cell percentage was negatively correlated with age (r = -0.254, p = 0.046). CONCLUSION: Our results suggest that neither PD-1 nor its ligands represent relevant targets for MCL treatment. Age may impact the efficiency of immune checkpoint inhibitors and could be related to the increased incidence of MCL with age.

The utility of IMP3 immunohistochemical staining in differentiating nodular lymphocyte predominant Hodgkin Lymphoma from T-Cell/Histiocyte-Rich large B-Cell lymphoma.

INTRODUCTION: Nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) and T cell/histiocyte-rich large B-cell lymphoma (THRLBCL) have overlapping histological features that make their diagnosis challenging. Insulin-like growth factor II mRNA-binding protein 3 (IMP3) is a recently proposed diagnostic marker for Hodgkin's lymphoma. The aim of this study was to determine the ability of IMP3 in differentiating NLPHL from THRLBCL. METHODS: In this retrospective study, the formalin-fixed paraffin-embedded blocks from 56 patients (28 NLPHL and 28 large B cell lymphoma (LBCL, including 16 THRLBCL and 12 DLBCL, NOS) cases based on immunohistochemistry (IHC) were included. Sample sections were stained for IMP3 using IHC method. Moderate to strong staining in at least 10% of tumor cells was considered positive IMP3 expression. RESULTS: The mean age of the patients was 41.25 ± 16.08 years old. The majority of the patients were male. There was a significant age difference between NLPHL (34.61 ± 16.44 years old) and LBCL (47.89 ± 12.85 years) groups (p = 0.001). No significant difference was seen in gender and site between NLPHL and LBCL groups. The expression of IMP3 was mainly strong in LBCL group, while it was heterogeneously distributed among NLPHL samples ranging from weak to strong (p < 0.001). It was determined that strong IMP3 expression at 55.00% can differentiate LBCL from NLPHL with 71.4% sensitivity and 71.4% specificity. CONCLUSION: Our findings showed that IMP3 may be a good complement in differentiating NLPHL cases from THRLBCL.

Immunohistochemical expression of PD-L1 and its correlation with microsatellite status in endometrial and ovarian clear cell carcinomas: a cross-sectional study.

BACKGROUND: Clear cell carcinoma is an uncommon histologic subtype of ovarian and endometrial carcinoma with poor response to Platinium-based chemotherapy agents at high stages. Blockage of Programmed cell Death Ligand-1 (PD-L1), can be used in targeted immunotherapy. This study investigated Mismatch Repair Deficiency (MMR-D) status, PD-L1 expression, and the correlation between PD-L1 expression and microsatellite instability (MSI) status in ovarian and endometrial clear cell carcinomas. METHODS: Ovarian clear cell carcinoma (OCCC) (n = 28) and endometrial clear cell carcinoma (ECCC) (n = 28) samples were evaluated for PD-L1 (in tumoral and peri-tumoral inflammatory cells), MSH6 and PMS2 expression by immunohistochemistry (IHC) study. PD-L1 expression > 1% in tumor cells and > 5% in peritumoral inflammatory cells were considered positive. RESULTS: The prevalence of PD-L1 expression was higher in ECCC (20/28, 71.43%) compared to OCCC tumor cells (16/28, 57.15%) (p > 0.05), while expression in peritumoral inflammatory cells was significantly higher in ECCC (25/28, 89.29%) compared to OCCC (11/28, 39.28%) (p < 0.05). MMR-D was observed in 5 cases, four OCCCs and one ECCC, among which, four (80%) showed PD-L1 expression in peritumoral inflammatory and tumor cells. The only OCCC case with extensive PD-L1 expression in tumor cells (> 50%) exhibited MSH6/MSH2 loss. No significant correlation was noted between PD-L1 expression and the pathologic stage or survival. CONCLUSION: PD-L1 expression was significantly associated with clear cell morphology, especially in the endometrium, independent of MMR protein status.

The utility of PAX8 in comparison with PAX5 immunohistochemical staining in the diagnosis of Hodgkin lymphoma.

BACKGROUND: Hodgkin's lymphoma (HL) is among the most prevalent lymphomas worldwide. PAX5 has a great value in separating this entity from other T cell lymphoma; however, it is weakly expressed in neoplastic cells. Polyclonal PAX8 was positive in a variety of lymphoid neoplasms in several previous studies and the staining paralleled that of PAX5 but monoclonal PAX8 was negative in the same neoplasms. The aim of this study was to compare immunohistochemical patterns of monoclonal PAX8 with PAX5 in Classical and NLPHL samples. MATERIAL AND METHODS: This retrospective study was conducted on 89 formalin-fixed paraffin embedded blocks from HL patients (69 Classical and 20 NLPHL) admitted to Imam Khomeini and Dr. Shariati hospitals, Tehran, Iran during 2016-2020. Diagnoses were confirmed by reviewing previous immunohistochemistry (IHC) studies, including PAX5. All samples were stained for PAX8 (clone MRQ-50). Expression intensity scoring was made for both antibodies in neoplastic and background cells based on nuclear staining percentage. RESULTS: PAX8 was positive in neoplastic and background B lymphocytes of all classical and NLPHL samples. PAX8 Expression intensity was significantly higher in neoplastic and background cells compared to PAX5 in classical HL samples (P = 0.001). PAX5 expression intensity in neoplastic cells was significantly higher in NLPHL samples compared to classical HL (P = 0.040); however, no significant difference in PAX8 expression between neoplastic cells of NLPHL and HL was seen. PAX8 expression intensity was not significantly correlated with gender, histologic subtype, tumor location, and relapse. CONCLUSIONS: PAX8 monoclonal antibody (clone MRQ-50) showed strong nuclear reactivity in neoplastic and background cells of classical HL and NLPHL samples. Therefore, this marker can be utilized as a valuable alternative for PAX5 in differentiating HL from other T cell lymphoma in challenging cases.

Diagnostic value of glycophorin-A in comparison with P57 immunohistochemical staining method in differentiating complete and partial molar pregnancies.

INTRODUCTION: Current histomorphological criteria in distinguishing two subtypes of hydatidiform moles has considerable inter-observer variability and limitations. In this regard, ancillary studies can aid pathologist to obtain an accurate diagnosis. Herein, we evaluated the utility of Glycophorin-A (GLA) in differentiating complete and partial moles. MATERIALS AND METHODS: In this case-control study, formalin-fixed paraffin-embedded blocks of 47 patients with pathologic diagnosis of complete and 42 partial hydatidiform moles were included and the diagnoses were confirmed by immunohistochemistry (IHC) for P57. Sections from all samples were stained for GLA using IHC method. Using 2 × 2 tables, the sensitivity, specifity, Positive and Negative Predictive Values (PPV and NPV) as well as accuracy of GLA were determined. RESULTS: Primary pathologic diagnosis was changed in 7.1% and types of hydatidiform mole were specified in 11.9% of the cases after review of the slides and IHC study for P57. NRBCs were found in 52.7% of the PM cases and none of CMs by pathologist in H&E sections. IHC study for GLA revealed positive result in one case of complete moles (2%) and 31 case of partial mole samples (73.8%). It was negative in 98% of the complete mole and 11 (26.2%) of partial mole cases. DISCUSSION: The results of this study showed a significant association between GLA immunoreactivity and type of molar pregnancy. Diagnostic sensitivity, specificity and accuracy of this marker for discrimination of molar pregnancy were 73.8%, 98% and 86.5%, respectively. Therefore, this marker can be utilized in differentiating partial and complete hydatidiform mole.

Diagnostic challenges in fine needle aspiration cytology of salivary gland lesions.

BACKGROUND: Fine needle aspiration cytology (FNAC) has been widely accepted as a safe method for diagnosis of salivary gland lesions and its accuracy is increased with increasing the experience of the physician. This study was conducted to examine the sensitivity, specificity and accuracy of FNAC of salivary gland lesions by cyto-histological correlation and to identify the discrepancies that contribute to false diagnoses. METHOD: A retrospective study was carried out over a 7-year period from 2003 to 2009 to review the cases of patients with salivary gland lesions who underwent FNAC with histopathological confirmation. RESULTS: A total of 101 cases had cytological correlation of whom 76 (75.3%) were neoplastic (58.4% benign, 16.8% malignant) and 25 (24.7%) were nonneoplastic. Pleomorphic adenoma (PA) was the most frequent benign neoplasm while adenoid cystic carcinoma (ACC) was the most frequent malignant neoplasm. FNAC had a sensitivity of 80% and a specificity of 98.8% for overall benign and malignant diagnoses and positive predictive and negative predictive values of 92.3% and 96.4% respectively. The most common false negative cases were pleomorphic adenoma. CONCLUSIONS: This study demonstrated that FNAC of the salivary gland is a useful technique for diagnosis of salivary gland lesions. Combined with clinical and radiological findings, it can provide a preliminary assessment on which management decision can be based.

Evaluation of Immunohistochemical Expression of Survivin and its Correlation with qRT-PCR Results as a Useful Diagnostic Marker in Gastric Cancer.

Background: Today, survivin is known as one of the most specific cancer proteins; provide unique and practical study opportunities. Clinical value of survivin in gastric cancer (GC) is not yet appointed. To establish the expression level of survivin and its diagnosis value in Iranian patients with GC, we evaluated the association of survivin expression with clinicopathologic factors. Methods: Overall, 60 matched-normal controls with 60 GC samples including 30 cases with evidence of metastasis at time of our study and 30 cases without evidence of metastasis were recruited, in Tehran, Iran during 2008 to 2018. Survivin expression was evaluated by quantitative Real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC) study. Results: Increased expression of survivin at mRNA and protein levels was found in 86.7% and 71.6% of cases, respectively. Evidence indicated a significant difference in survivin mRNA expression level between tumor and nontumoral (marginal) tissues (P<0.001). The difference in expression of survivin mRNA was not significant between metastatic and non-metastatic tumor tissues (P=0.171). Positive immunoreactivity of survivin was observed to be predominantly in the nucleus of tumor cells. A significant difference in survivin protein expression was detected between tumor and non-tumoral tissues (P<0.001) and between metastatic and non-metastatic tumor tissues (P<0.001). There was no significant association between survivin mRNA expression and clinicopathological variables. However, survivin protein expression was significantly correlated with perineural involvement (P<0.018). Conclusion: This data could be supportive of using survivin as a useful diagnostic marker in GC. Although, more research is needed in this area.

The expression of lncRNAs CASC2, NEAT1, LINC00299 in breast cancer tissues and their relationship with the XBP1 splicing rate in Iranian patients during 2014-2019: A cross-sectional study.

Background and Aims: Breast cancer is a leading cause of incidence and mortality in women globally. Identifying new molecular markers can aid in cancer diagnosis, targeted therapy, and treatment monitoring. This study aimed to measure the expression of the X-box binding protein 1 (XBP1) gene, an index of the unfolded protein response (UPR), and long noncoding RNAs (lncRNAs), including Nuclear Enriched Abundant Transcript 1 (NEAT1), Cancer Susceptibility Candidate 2 (CASC2), and Long Intergenic Nonprotein Coding RNA 299 (LINC00299), as possible regulators of the UPR pathway. Methods: Total RNA was extracted from 40 samples of breast tumor tissues and their respective controls. The expression level of lncRNAs CASC2, NEAT1, and LINC00299 was quantified using reverse transcription-polymerase chain reaction (RT-PCR). The ratio of the spliced form of XBP1 to its unspliced form (XBP1u) was determined by PCR and electrophoresis. Results: The results showed a 2.8-fold increase in the ratio of XBP1s/u in breast cancer tissues compared to adjacent nonmalignant samples (p < 0.05). Additionally, the level of lncRNAs NEAT1, CASC2, and LINC00299 in breast tumor tissues increased significantly by twofold, 1.5-fold, and 2.3-fold, respectively, compared to adjacent nonmalignant samples (p < 0.05). Conclusions: Based on the association between the expression of lncRNAs CASC2, LINC00299, and NEAT1 and the XBP1s/u ratio, these lncRNAs could be potential regulators of the UPR pathway. Also, CASC2 and NEAT1 genes could be suggested as suitable biomarkers to distinguish cancerous tissue from noncancerous breast tissue due to their significant increase in expression in cancerous samples compared to adjacent noncancerous.

Significance of Endocan Expression in Various Types of Epithelial Ovarian Tumors.

Background & Objective: Ovarian cancer is associated with the highest mortality rate among gynecologic malignancies. Despite new therapeutic strategies, ovarian cancer still has a high risk of metastasis and mortality. Endocan is a newly identified endothelial cell activation marker, which is responsible for angiogenesis, tumor invasion, and aggressive behavior of tumors. The aim of this study was to assess Endocan expression in different types of ovarian tumors and to identify its relationship with clinicopathologic characteristics of ovarian tumors. Methods: This cross-sectional study was conducted on 183 tissue samples, including benign, borderline, and malignant ovarian tumors collected from the University Kebangsaan Malaysia Medical Center archive of Pathology during 2005-2015. Mouse monoclonal anti-human Endocan/ESM-1 Clone MEP08 was used at a dilution of 1:400 for immunohistochemical (IHC) staining. All the information was collected by a checklist, and the association between clinicopathological features and high or low levels of Endocan -MVD was evaluated using Pearson chi-square, Fischer's exact, or Monte Carlo tests. Results: The prevalence of Endocan positivity was significantly higher in malignant compared to borderline and benign ovarian tumors (P<0.001). There was also a significant association between type of tumor and Endocan status in malignant ovarian tumors (P=0.02), indicating that Endocan positivity was more likely in serous malignant ovarian tumors compared to other ovarian tumor types. However, the tumor stage was not significantly associated with Endocan status (P=0.31). Conclusion: This study showed that Endocan positivity may show the highest prevalence among malignant tumors suggesting that high Endocan expression would be negatively associated with ovarian tumor behavior.

High Frequency of Microsatellite Instability among Non-Metastatic Gastric Cancer.

Background: Microsatellite instability (MSI) is considered a key factor in carcinogenesis and a genetic alteration pattern in many types of cancers such as gastric cancer (GC). Although the role of MSI in colorectal cancer (CRC) is well known, its prognostic impact on GC has not been clearly defined. The assessment of MSI in GC has not been documented in the Iranian population yet. Therefore, this study analyzed the association of MSI status with GC in Iranian patients. Materials and Methods: We compared the frequency of MSI at 5 loci from formalin-fixed paraffin-embedded (FFPE) gastrectomy specimens, between metastatic and non-metastatic cases of GC (N = 60). A panel of five quasi-monomorphic markers and a single dinucleotide marker with linker-based fluorescent primers was used. Results: MSI was observed in 46.6% of cases, including MSI-high (H) (33.3%) and MSI-Low (L) (13.3%). Moreover, the most unstable and stable markers in our study were NR-21 and BAT-26 accordingly. MSI-H and MSI were seen more frequently in non-metastatic tumors (p= 0.028 and p= 0.019, respectively). Conclusion: The current study showed MSI status more frequently in non-metastatic GC which may reflect a good prognostic factor in GC like CRC. Although, larger and more comprehensive studies are needed to confirm this statement. A panel consisting of NR-21, BAT-25, and NR-27 mononucleotide markers appears to be reliable and useful markers for detecting MSI in GC in Iranian patients.

Evaluation of TS and ENOSF1 Variants as a Biomarker in Response to Neoadjuvant Chemotherapy based on 5FU in Gastric Cancer Patients.

OBJECTIVE: Neoadjuvant chemotherapy with 5-fluorouracil (5FU) is one of the most effective treatment options for gastric cancer patients.  However, treatment response varies significantly between patients based on their genetic profile. The purpose of this study was to determine the association between thymidylate synthase (TS) and enolase superfamily member 1 (ENOSF1) polymorphisms, treatment response, and overall survival in patients with gastric cancer. METHODS: The TS and ENOSF1 variants were analyzed in formalin-fixed paraffin-embedded (FFPE) tissue from 100 gastric cancer patients receiving neoadjuvant 5FU-based chemotherapy. Polymerase chain reaction (PCR) amplification and restriction fragment length polymorphism (RFLP) were used to determine TS polymorphisms' genotypes, and the Tetra Arms PCR method was used to identify ENOSF1 polymorphisms. Patients were followed for up to five years, and the association between variants, treatment response, and overall survival (OS) was examined. RESULTS: There was a significant association between the TS 5' UTR polymorphism and response to treatment in patients with gastric cancer who received neoadjuvant 5FU therapy (P=0.032). Patients with the 2R3R genotype responded better to treatment, whereas those with the 3R3R genotype did not respond to treatment. Patients with the 2R2R and 3R3R genotypes had the longest and shortest median survival times, respectively, and the observed differences were significant (p=0.003). There was a statistically significant relationship between rs2612091 and chemotherapy response (P=0.017). Patients with genotype AG did not respond to treatment. CONCLUSION: This study established that the TS 5' UTR and ENOSF1 rs2612091 polymorphisms could be used to predict treatment response and overall survival in patients with gastric cancer who received neoadjuvant chemotherapy based on 5FU.

Struma ovarii: A case report and review the literature.

INTRODUCTION AND IMPORTANCE: Struma ovarii is a monodermal teratoma which characterized by the presence of thyroid tissue. The symptoms of this tumor are nonspecific and thus misdiagnosis and indifference to other ovarian lesions are very common. CASE PRESENTATION: Herein, we described a case of struma ovarii that was successfully diagnosed and managed. The tumor is mimicking a malignant tumor based on ascites and tumor marker assessments. Although, thyroid function indices are normal. CLINICAL DISCUSSION: The initial footprint of the tumor is mostly based on incidental imaging, but definitive diagnosis is possible based on pathological studies. Surgical resection of the tumor can be led to successful treatment and prognosis. CONCLUSION: Struma ovarii is a rare tumor and also misdiagnosis is common. Regarding rarity of Struma Ovarii, the treatment option is debated. However, in postmenopausal cases with the aim of completely removing the symptoms, total abdominal hysterectomy with bilateral salpingo-oophorectomy can be occasionally indicative.

Disseminated tuberculosis with myelofibrosis presentation: a case report.

BACKGROUND: Primary myelofibrosis is a rare myeloproliferative disorder in middle-aged and old adults and should be distinguished from secondary and reactive causes of bone marrow fibrosis because, in reactive fibrosis, treatment approaches depend on the underlying etiology. CASE PRESENTATION: Here we report the case of a middle-aged Iranian man who was diagnosed and treated as primary myelofibrosis at presentation, and whose final diagnosis was disseminated tuberculosis with reactive bone marrow fibrosis. CONCLUSIONS: It is prudent to evaluate the potential causes of myelofibrosis in any patient with the diagnosis primary myelofibrosis. Tuberculosis can be an important etiology of bone marrow fibrosis, especially in endemic areas.

Burned-out Post Pubertal Teratoma Presenting as a Liver Metastases in a 34-Year-Old Male.

Germ cell teratomas belong to non-seminomatous germ cell tumors and account for 95% of malignant testicular tumors. Regarding the current World Health Organization (WHO) criteria, testicular teratomas are divided into prepubertal and post-pubertal subtypes based on patients' age. The term "burned-out testicular tumor" is a very rare condition referring to a regressed testicular tumor which presents with its metastases without any clinical finding in the testicle. Metastasis can be the presentation of post-pubertal teratoma in 22-37% of cases. In scar associated teratoma (burn-out component), the metastasis rate is 66%. We reported a rare case of post-pubertal teratoma in a 34-year-old male who presented with multiple liver masses initially. Liver biopsy revealed poorly differentiated adenocarcinoma probably of gastrointestinal (GI) tract origin. The upper and lower GI endoscopy were normal. Scrotal ultrasonography showed a hypoechoic cystic intratesticular lesion in the left testis. The patient underwent radical orchiectomy and the histopathologic examination revealed post-pubertal teratoma with burned out component. The patient underwent proper treatment and is still under follow up. As a result, in a young male patient who presented with a retroperitoneal mass or poorly differentiated carcinomas of an unknown primary site, using light microscopy and immunohistochemical profiling alone may be inadequate. Therefore, scrotal screening and physical examination of the scrotum and bilateral testis should be considered to exclude possibility of a metastatic progression from a testicular germ cell neoplasia.

Tumor-Derived Matrix Metalloproteinase-13 (MMP-13) Expression in Benign and Malignant Breast Lesions.

INTRODUCTION: Breast carcinoma is the most common malignancy and the leading cause of cancer death in women. Matrix metalloproteinase-13 (MMP-13) is a hypothetical prognostic marker in invasive breast cancer. This study aimed to determine MMP-13 expression in benign and malignant breast lesions and to evaluate the correlation between MMP-13 expression and tumor characteristics in invasive ductal carcinoma (IDC). MATERIALS AND METHOD: We evaluated cytoplasmic expression of MMP-13 based on staining index using immunohistochemistry (IHC) in epithelial cells, stromal fibroblasts of IDC (n=90) and benign epithelial breast (n=90) lesions. Correlation between IHC and tumor size, lymph node status, distance metastasis, estrogen receptor (ER), progesterone receptor (PR) and Her-2/neu was assessed. RESULTS: MMP-13 expression was 45% and 38.8% in malignant epithelial cells and peritumoral fibroblasts, respectively. Only low level of MMP-13 expression was seen in benign breast lesions (8.8% in epithelial component and 2.2% in stromal fibroblasts), while high level of MMP-13 expression was noted in malignant tumors, mainly grade II or III. Cytoplasmic MMP-13 expressions in epithelial tumor cells was correlated significantly with peritumoral fibroblasts. MMP-13 expression was directly correlated with distant metastasis and tumor stage in epithelial tumoral cells and was inversely correlated with progesterone expression in both tumoral and stromal cells. CONCLUSION: This study showed that MMP-13 was a moderator for tumor invasion and metastasis and could be an independent predictor of poor prognosis in breast cancer. The role of MMP-13 in predicting the risk of malignant transformation in benign lesions should be further investigated.

Diagnostic Value of TROP2 Expression in Papillary Thyroid Carcinoma.

Papillary thyroid carcinoma (PTC) represents the most common primary malignant thyroid lesion in all age groups. As diagnosis of PTC could be challenging in some cases and borderline nuclear features could be seen in some benign mimickers, several immunohistochemical markers are proposed to be helpful for making the correct diagnosis. In this study the authors investigated the diagnostic value of transmembrane glycoprotein (TROP2) for differentiating PTC from other thyroid follicular lesions. A total of 155 total thyroidectomy specimens including 84 cases of PTC and 71 cases of non-PTC were investigated. Among non-PTC group, 45 cases were follicular neoplasms and 26 cases were Hashimoto thyroiditis. TROP2 expression was observed in 82 of 84 cases of PTC group. In contrast only 5 cases of non-PTC group, all from Hashimoto thyroiditis specimens, showed positive expression. The sensitivity, specificity, positive predictive value, and negative predictive value of TROP2 for diagnosis of PTC was 98%, 93%, 94%, and 97%, respectively. The authors concluded that high sensitivity and specificity of TROP2 as well as its uniform negative reaction in follicular adenoma and carcinoma makes it a valuable immunohistochemical marker for diagnosis of PTC.

Intravascular Large B-cell Lymphoma: A Report of Two Cases.

One of the rare variants of extranodal large B-cell lymphoma is intravascular large B-cell lymphoma (IVLBCL). Characteristics of IVLBCL include intraluminal selective proliferation of atypical lymphoid cells in small to medium-sized vessels. The etiologic of IVLBCL is unknown, but due to the growth pattern of this tumor, it is speculated that IVLBCL is caused by a defect in homing receptor of tumor cells. IVLBCL can involve any organ but central nervous system, lungs, and skin are the most involved sites. IVLBCL does not usually involve lymph nodes. IVLBCL mainly occurs in the middle aged to elderly population with a slight male predominance. Generally, IVLBCL is aggressive and rapidly fatal if left untreated. We here reported two cases of IVLBCL who succumbed to the disease at initial phase of treatment to emphasize the difficulty in diagnosis of IVLBCL due to its exclusive intravascular growth pattern and fulminant clinical course.