Eosinophilic solid and cystic renal cell carcinoma with aggressive behavior: Two case reports.

BACKGROUND: Eosinophilic solid and cystic (ESC) renal cell carcinoma (RCC), a unique and emerging subtype of RCC, has an indolent nature; in some rare instances, it may exhibit metastatic potential. Current cases are inadequate to precisely predict the clinical outcome of ESC RCC and determine treatment choices. CASE SUMMARY: Herein, we report two patients with ESC RCC. Patient 1 was a young woman with classical pathological characteristics. Patient 2 was a 52-year-old man with multifocal metastases, involving the pulmonary hilar and mediastinal lymph nodes, liver, brain, mesosternum, vertebra, rib, femur, and symphysis pubis. Awareness of ESC RCC, along with its characteristic architecture and immunophenotype, would contribute to making a definitive diagnosis, even on core biopsy samples. CONCLUSION: The discovery of ESC RCC molecular signatures may provide new therapeutic strategies in the future.

Parathyroid Hormone-Related Protein-Producing Adenocarcinoma Suspicious of Lung Cancer: A Case Report.

Introduction: Lung adenocarcinoma with parathyroid hormone (PTH)-related hypercalcemia is uncommon. Case Presentation: A 69-year-old man was admitted to our hospital due to anorexia and fatigue. Serum calcium (15.0 mg/dL) and carcinoembryonic antigen (361.7 ng/mL) were extremely high, and PTH-related protein (PTH-rP) also elevated (16.7 pmol/L). Systemic computed tomography revealed multiple enlarged lymph nodes and disseminated peritoneal nodules, with irregularly shaped nodules in the upper lobe in the left lung. Ultrasound-guided biopsy from the axillary lymph node revealed adenocarcinoma. Immunohistological staining showed the tumor cells to be positive for cytokeratin 7 and PTH-rP and negative for cytokeratin 20 and thyroid transcription factor-1. Although the primary origin remains undetermined despite detailed examinations, possible primary tumor was considered to be lung adenocarcinoma in the present case. The serum calcium level was reduced by denosumab, but the patient died 20 days after admission. Conclusion: The present case demonstrated the importance of considering oncological emergency, such as hypercalcemia and/or PTH-rP-producing hypercalcemia, in patients with adenocarcinoma.

Expression of cytokeratin 7/20 and Ki67 in Helicobacter pylori-associated gastritis and intestinal metaplasia.

INTRODUCTION: Cytokeratins (CKs) have been associated with precancerous and cancerous gastric lesions in patients with Helicobacter pylori-associated chronic gastritis, making them useful for diagnosing epithelial tumors. METHODOLOGY: A retrospective study was conducted utilizing 200 formalin-fixed paraffin-embedded gastric biopsy samples collected from the lesser curvature of the stomach. Samples from the control group, patients with H. pylori infection, and patients with H. pylori-associated gastritis, with complete and incomplete intestinal metaplasia (IM) were immunostained. Monoclonal antibodies were utilized to determine the expression of CK7, CK20, and Ki-67. RESULTS: Patients infected with H. pylori had strong CK20 expression on the surface, and weak CK7 expression on the surface and deep glands; while non-specific chronic gastritis patients had weak focal CK7 expression and strong CK20 expression. The normal gastric mucosa of patients in the control group had relatively weak CK7 expression, restricted to a few cells in the neck and deep glands. CK20 showed diffuse strong reactivity on the surface. On the other hand, patients with complete IM showed a CK7 staining pattern that was either negative or weakly focal on the surface and crypts associated with diffuse surface CK20 and focal crypt staining corresponding to gastric type IM. The Ki67 proliferating index was low (≤ 15%) in H. pylori infected patients, high (> 30%) in patients with incomplete IM, and intermediate (16-30%) in patients with complete IM. CONCLUSIONS: These results indicate a significant link between the expressions of CK7/CK20 and Ki67 in patients afflicted with H. pylori and IM.

Enhancing upper tract urothelial carcinoma diagnosis: Utility of cytokeratin 17 and CK20/CD44/p53 immunohistochemical panel.

Upper tract urothelial carcinoma (UTUC) presents diagnostic challenges due to small biopsy specimen size, poor orientation, and technical obstacles that can yield equivocal diagnoses. This uncertainty often mandates repeated biopsies to evaluate the necessity of nephroureterectomy. Prior studies have suggested cytokeratin 17 (CK17) immunostain as an adjunctive tool for diagnosing bladder urothelial neoplasia in both urine cytology and tissue biopsy specimens. We evaluated the utility of CK17 in differentiating UTUC from benign urothelium and its ability to stratify low-grade from high-grade neoplasia. Our study involved a cohort of previously diagnosed cytology (n = 29) and tissue specimens from biopsies and resections (n = 85). We evaluated CK17 staining percentage in cytology and tissue samples and localization patterns in biopsy/resection samples. Our findings showed a statistically significant distinction (p < 0.05) between UTUC and benign tissue specimens based on full thickness localization pattern (odds ratio 8.8 [95% CI 1.53-67.4]). The percentage of CK17 staining failed to significantly differentiate neoplastic from non-neoplastic cases in cytology or tissue samples. Additionally, based on prior research showing the efficacy of CK20/CD44/p53 triple panel in bladder urothelial neoplasia, we utilized tissue microarrays to evaluate if these markers could distinguish UTUC from benign urothelium. We found that CK20/CD44/p53, individually or in combination, could not distinguish urothelial neoplasia from non-neoplasia. Full thickness CK17 urothelial localization by immunohistochemistry was highly reproducible with excellent interobserver agreement and may play a supplementary role in distinguishing upper tract urothelial neoplasia from benign urothelium.

Immunohistopathological Study of Papillary Squamotransitional Carcinoma of Uterine Cervix.

INTRODUCTION: Papillary squamotransitional cell carcinoma (PSTCC) arising from the uterine cervix is a distinctive histomorphological subtype of squamous cell carcinoma (SCC) not otherwise specified (NOS) of cervical epithelial tumors. AIM: The present study was undertaken to study the histopathological features and immunoexpression of CK7, CK20, p53 and Ki-67 in PSTCC of the cervix. MATERIALS AND METHODS: This study included 43 cases of PSTCC of cervix. A technique of manual tissue array was employed along with IHC staining of entire section in some cases. The expression pattern of CK7, CK 20, p53 and Ki67 in PSTCC was studied and clinico-pathological correlation of various parameters with IHC expression of CK7 and CK20 was observed. Results were subjected to statistical analysis and were considered significant when the p-value was less than 0.05. RESULTS: Out of 43 PSTCC cases, there were 38 squamotransitional type and 5 papillary type. Histomorphologically, all the cases studied were having fused papillae with rounded contours and fibrovascular cores with highest number of cases having intermediate cell type morphology (86%). Stromal invasion was seen in 74.4% of cases. Koilocytosis were seen in 39.3% of cases. Thirty-two cases showed CK7 immunopositivity (+) and CK20 immunonegativity (-), nine cases were both CK7 and CK20 - and two cases were CK7- and CK20+. Among them 90.7% cases were p53 positive and all cases were positive for Ki67 immunostaining with highest number of cases showing moderate proliferative activity (74.4%); followed by nine cases showing high (20.93%) and two cases showing low proliferative activity (4.65%). CONCLUSION: The distinct histomorphology and CK7/CK20 immnunoprofile of PSTCC along with Ki67 and p53 could help in arriving at an accurate diagnosis as well predicting its biological behavior.

Quest to develop a standard screening method for urothelial carcinoma using liquid-based cytology (The Paris System) and CK20.

Background: Bladder cancer, the most common malignancy of the urinary tract is a leading cause of morbidity and mortality. But cystoscopy, which is till now the mainstay of screening, is an invasive, high-cost method with low sensitivity especially for flat lesions. Aim: To find a non-invasive and effective screening method with liquid-based cytology (LBC) using The Paris System (TPS) and CK20 immunocytochemistry. Materials and Methods: It was a prospective study including the patients with clinical or cystoscopic diagnosis of urinary bladder space occupying lesions (SOL). Both conventional (CC) and liquid-based cytology slides were prepared from urine samples. Slides were evaluated by two trained pathologists and categorized according to TPS guidelines. CK20 immunocytochemistry (ICC) was also performed. Consequent formalin-fixed paraffin embedded sections were blindly examined by another pathologist and was taken as gold standard for comparison. Statistical Analysis: All the statistical analysis were done using MedCalc version 15.8 [Mariakerke, Belgium: MedCalc Software 2015]. Results: The study included 150 cases with a mean age of 62.4 years. Five cases revealed unsatisfactory smears. Rest of the cases were categorized as the following: 18.1% as NH-GUC, 8% as LGUN, 22.1% as AUC, 15.4% as SH-GUC, 32.9% as HGUC. Kappa value of CC and LBC were strong (0.854). LBC alone showed very low specificity (58%) and PPV (74.8%) which improved on application of ICC (specificity: 97.4%, PPV: 96.3%). Conclusion: We conclude that CK20 ICC offers potential for accurate, non-invasive detection and surveillance of bladder cancer and is a better tool when combined with liquid-based cytology, reported using The Paris System.

Ampullary Cancer: Histological Subtypes, Markers, and Clinical Behaviour-State of the Art and Perspectives.

There are different cancers in the peri-ampullary region, including pancreatic ductal adenocarcinoma (PDAC), duodenum cancers (DCs), and ampullary adenocarcinoma (AAC). Here, significant morphological-molecular characterizations should be necessary for the distinction of primary tumours and classifications of their subtypes of cancers. The sub classification of AACs might include up to five different variants, according to different points of view, concerning the prevalence of the two more-cellular components found in the ampulla. In particular, regarding the AACs, the most important subtypes are represented by the intestinal (INT) and the pancreato-biliary (PB) ones. The subtyping of AACs is essential for diagnosis, and their identifications have been impacting clinical management responses to treatments and overall survival (os) after surgery. Pb is associated with a worse clinical outcome. Otherwise, the criteria, through which are possible to attribute its subtype classification, are not well established. A triage of immune markers represented by CK7, CK20, and CDX-2 seem to represent the best compromise in order to split the cohort of AAC patients in the INT and PB groups. The test of choice for the sub-classification of AACs is represented by the immuno-histochemical approach, in which its molecular classification acquires its diagnostic, predictive, and prognostic value for both the INT and PB patients.

CK-7 negative primary lung adenocarcinoma.

Cytokeratin (CK) 7 is normally expressed in the vast majority of lung adenocarcinoma (ADC). However, on rare occasions, as reported in this paper, CK7 negativity can challenge the diagnosis of pulmonary ADC. Hence, the need to use a combination of 'immunomarkers' such as thyroid transcription factor 1, Napsin A, p40, p63 and CK20.

Diagnostic gastrointestinal markers in primary lung cancer and pulmonary metastases.

Histopathological diagnosis of pulmonary tumors is essential for treatment decisions. The distinction between primary lung adenocarcinoma and pulmonary metastasis from the gastrointestinal (GI) tract may be difficult. Therefore, we compared the diagnostic value of several immunohistochemical markers in pulmonary tumors. Tissue microarrays from 629 resected primary lung cancers and 422 resected pulmonary epithelial metastases from various sites (whereof 275 colorectal cancer) were investigated for the immunohistochemical expression of CDH17, GPA33, MUC2, MUC6, SATB2, and SMAD4, for comparison with CDX2, CK20, CK7, and TTF-1. The most sensitive markers for GI origin were GPA33 (positive in 98%, 60%, and 100% of pulmonary metastases from colorectal cancer, pancreatic cancer, and other GI adenocarcinomas, respectively), CDX2 (99/40/100%), and CDH17 (99/0/100%). In comparison, SATB2 and CK20 showed higher specificity, with expression in 5% and 10% of mucinous primary lung adenocarcinomas and both in 0% of TTF-1-negative non-mucinous primary lung adenocarcinomas (25-50% and 5-16%, respectively, for GPA33/CDX2/CDH17). MUC2 was negative in all primary lung cancers, but positive only in less than half of pulmonary metastases from mucinous adenocarcinomas from other organs. Combining six GI markers did not perfectly separate primary lung cancers from pulmonary metastases including subgroups such as mucinous adenocarcinomas or CK7-positive GI tract metastases. This comprehensive comparison suggests that CDH17, GPA33, and SATB2 may be used as equivalent alternatives to CDX2 and CK20. However, no single or combination of markers can categorically distinguish primary lung cancers from metastatic GI tract cancer.

Cutaneous Metastasis of Transverse Colon Cancer with an Aberrant Pattern of CK7/CK20/CDX2 and High Microsatellite Instability.

A 79-year-old woman was diagnosed with transverse colon cancer, moderately differentiated adenocarcinoma. She underwent surgery and postoperative adjuvant chemotherapy. At 80 years old, the patient exhibited changes in skin tone at the chest and abdomen with CK7+/CK20-/CDX2- immunostaining that was later identified as poorly differentiated adenocarcinoma. The diagnosis was cancer of unknown primary origin. The patient passed away three months after the detection of the skin lesion. Autopsy revealed recurrence at the transverse colon, multiple organ metastases, a similar postmortem immunostaining pattern, and high-frequency microsatellite instability (MSI-high). We herein report this case of CK7+/CK20-/CDX2- and MSI-high transverse colon cancer showing cutaneous metastasis.

Cytokeratin 20 expression is linked to stage progression and to poor prognosis in advanced (pT4) urothelial carcinoma of the bladder.

Cytokeratin 20 (CK20) expression is limited to umbrella cells in the normal urothelium. Since CK20 is often upregulated in neoplastic urothelial cells including dysplasia and carcinoma in situ, immunohistochemical CK20 analysis is often used for the assessment of bladder biopsies. CK20 expression is a feature of luminal bladder cancer subtype, but its prognostic relevance is disputed. In this study, we investigated CK20 on >2700 urothelial bladder carcinomas in a tissue microarray format by immunohistochemistry. Cytoplasmic and membranous CK20 staining was seen in 1319 (51.8%) cancers. The fraction of CK20 positive and especially strongly positive cases increased from pTaG2 low grade (44.5% strongly positive) and pTaG2 high grade (57.7%) to pTaG3 high grade (62.3%; p = 0.0006) but was lower in muscle-invasive (pT2-4) carcinomas (51.1% in all pTa vs. 29.6% in pT2-4; p < 0.0001). Within pT2-4 carcinomas, CK20 positivity was linked to nodal metastasis and lymphatic vessel invasion (p < 0.0001 each) and to venous invasion (p = 0.0177). CK20 staining was unrelated to overall patient survival if all 605 pT2-4 carcinomas were jointly analyzed but subgroup analyses revealed a significant association of CK20 positivity with favorable prognosis in 129 pT4 carcinomas (p = 0.0005). CK20 positivity was strongly linked to the expression of GATA3 (p < 0.0001), another feature of luminal bladder cancer. The combined analysis of both parameters showed best prognosis for luminal A (CK20+/GATA3+, CK20+/GATA3-) and worst outcome for luminal B (CK20-/GATA3+) and basal/squamous (CK20-/GATA3-) in pT4 urothelial carcinomas (p = 0.0005). In summary, the results of our study demonstrate a complex role of CK20 expression in urothelial neoplasms including neoexpression in pTa tumors, a subsequent loss of CK20 expression in a subset of tumors progressing to muscle-invasion, and a stage dependent prognostic role in muscle-invasive cancers.

A review of 14 cases of perianal Paget's disease: characteristics of anorectal cancer with pagetoid spread.

BACKGROUND: Perianal Paget's disease (PPD) is an intraepithelial invasion of the perianal skin and is frequently associated with underlying anorectal carcinoma. The relatively rare nature of this disease has made it difficult to develop treatment recommendations. This study aims to analyze the clinical and pathological features of perianal Paget's disease (PPD) and to explore rational treatment options and follow-up for this disease. METHODS: The National Cancer Center Hospital database was searched for all cases of perianal Paget's disease diagnosed between 2006 and 2021. In the 14 patients identified, we reviewed the diagnosis, management, and outcomes of adenocarcinoma with pagetoid spread, including suspected or recurrent cases. RESULTS: All 14 cases met the inclusion criteria. The median follow-up period after diagnosis was 4.5 (range, 0.1-13.0) years. Pagetoid spread before initial treatment was suspected in 12 cases (85.7%). Underlying rectal cancer was identified in 6 cases, and no primary tumor was detected in the other 6 cases. Seven patients had recurrent disease, with the median time to recurrence of 34.6 (range, 19.2-81.7) months. The time to the first relapse was 3 months, and that to the second relapse was 6 months. The overall 5-year survival rate was 90.0%. CONCLUSIONS: Endoscopic and radiologic evaluation, as well as immunohistologic examination, should be performed. is to differentiate PPD with and without underlying anorectal carcinoma. The time to first recurrence varies widely, and long-term and regular follow-up for more than 5 years is considered necessary for local recurrence and distant metastasis.

Comprehensive optimization of urinary exfoliated tumor cells tests in bladder cancer with a promising microfluidic platform.

BACKGROUND: Enrichment of urinary exfoliated tumor cells (UETCs) is a noninvasive way of bladder cancer diagnosis, but the lack of specific capture and identification of tumor cells from the urine remains a limitation that impedes the development of liquid biopsy. METHODS: The CytoBot® 2000, a novel circulating cell isolation and enrichment platform, was used for UETCs isolation after comprehensive optimization. The commercial cell lines of bladder cancer were used in spiking assay for cell recovery test. The flow cytometry and immunofluorescent staining assays were performed for expression validation of capture target and identification markers. The performance of optimized platform was validated by 159 clinical samples and analyzed using receiver operator characteristic curve. RESULTS: The chip that had a pore diameter of 15*20 µm could reduce the background residues while maintaining a higher cell recovery rate. We found that the cell capture ability of chip significantly improved after anti-EpCam antibody encapsulation, but not with T4L6FM1. In identification system optimization, the spiking assay and validation of clinical sample showed that the performance of CK20 and DBC-1 were better that pan-CK in tumor cell identification, in addition, the staining quality is more legible with CK20. CONCLUSION: The optimized capture chip is more specific for UETCs isolation. CK20 and DBC-1 are both sensitive biomarkers of UETCs in bladder cancer diagnosis. The performance of this optimized platform is excellent in clinical test that improves the accuracy of urine cell testing and provides a new alternative for the clinical application of BLCA liquid biopsy assessment.

Colon Cancer With Metastatic Involvement of the Thyroid Incidentally Found at Excision of Parathyroid Adenoma.

Metastatic disease from primary colon cancer in the thyroid is rare. The authors have submitted such a case. What makes this case particularly unusual is that it was in a man. 80% of such cases are in women. It has been speculated that there may be a humoral component. What is even more unique in this case is that it was found during the workup of a symptomatic parathyroid adenoma. The diagnosis was confirmed with immunochemistry using markers Cytokeratin 20 (CK20), Cytokeratin 7 (CK7), and Thyroid Transcription Factor 1 (TTF-1) .

Merkel cell number and distribution, and CD200 expression in patients with lichen planopilaris and discoid lupus erythematosus.

BACKGROUND: Immune mechanisms are considered to be responsible for the pathogenesis of cicatricial alopecia in lichen planopilaris (LPP) and discoid lupus erythematosus (DLE) diseases. CD200 has an immunomodulatory function in hair follicles. The functions of Merkel cells (MCs) in hair follicles remain to be fully understood. OBJECTIVE: This study aimed to determine the number and distribution of MCs as well as CD200 expression in patients with DLE and LPP. METHODS: Using immunohistochemistry, the number and distribution of MCs (staining with CK20) and CD200 expression in biopsy specimens of LPP and DLE patients were compared with control group patients. RESULTS: The number of follicular MCs, total MCs, mean follicular MCs, and CD200 expression were significantly lower in the case groups compared to the control group. In CD200- cases, the number of follicular MCs and mean follicular MCs were significantly lower than in CD200+ cases. Retrospective design, lack of data regarding the history of alopecia in the control group, and unknown stage of disease in patients were the limitations. CONCLUSION: MC loss might play a role in immune privilege collapse in hair follicles. This study is novel in terms of investigating MCs in DLE and LPP patients.

The value of BCL2 and CK20 expression in predicting behavioral patterns of bladder cancer, a cross sectional study.

Background: Several biomarkers have been investigated to predict the biological behavior and prognosis of patients with bladder cancer. We evaluated the role of two important markers including BCL2 and CK20 in evaluating the biological behavior of bladder tumors. Methods: This cross-sectional study was performed on 30 patients suffering from one of the neoplasms of the bladder. To evaluate the expression of BCL2 and CK20 markers, the neoplastic tissue sample was initially extracted and immunohistochemistry staining was employed. Results: The positivity of CK20 and BCL2 in the patients' specimens was found to be 53.3% and 10.0%, respectively. There was no association between CK20 and BCL2 expressions and tumor size, tumor stage, or tumor-related vascular invasion, but BCL2 expression was shown to be higher in the low-grade specimens, while the expression rate of CK20 was found to be significantly higher in high grade samples. Conclusion: Evaluation of the expression of CK20 and BCL2 markers can be very valuable in predicting bladder tumor grade.

An Immunohistochemical Expression of CK5/6, CK7, and CK20 on Cell Blocks in Metastatic Cervical Lymphadenopathy.

Background: The neck is a common site of both primary and secondary malignancies. Many tumors from the head and neck (oral cavity, larynx, and pharynx), lung, and gastrointestinal tract metastasize to cervical lymph nodes. At most times, tumors are diagnosed by morphology, sometimes it is difficult to diagnose an unknown primary presenting as metastatic lymphadenopathy solely on the basis of morphology. Specific histological cell types can be confirmed by the use of immunohistochemistry. Aim: The present study evaluated the utility of cell block over fine-needle aspiration cytology (FNAC) and immunohistochemical expression of CK5/6, CK7, and CK20 in metastatic cervical lymphadenopathy. Methods: This prospective study design was used on a total of 50 cases. FNAC smears and cell blocks were made in all the cases. All the cell blocks were compared with FNAC findings and further subjected to immunohistochemical (IHC) analysis. The necessary statistical analysis was done. Results and Conclusion: Our study showed that the combined use of the cell block technique and FNAC was more useful and sensitive in diagnosing the metastatic cervical lymph nodes and the accuracy can be further improved by the use of IHC on the cell blocks. The combined use of CK5/6, CK7, and CK20 in metastatic cervical lymphadenopathy is helpful in diagnosing squamous cell carcinoma and adenocarcinoma with known/unknown primary sites.

Mucinous adenocarcinoma of the prostatic urethra after brachytherapy for prostatic adenocarcinoma: a case series.

Mucinous adenocarcinoma of the urethra is extremely rare, even more so in a setting of postradiation therapy, with only 3 cases reported up to date including the first case published by our group in 2011. In the present study, we included the long-term follow-up on our previously reported case and report 3 additional cases. This is the first case series to date of this rare disease entity. The aim of this study is to review the clinicopathologic features of mucinous adenocarcinoma of the prostatic urethra in patients after receiving brachytherapy for prostatic adenocarcinoma. We identified 4 patients with a mean age of 72 years, and a mean interval of 14.8 years from brachytherapy for prostate carcinoma (grade group 1). Patients presented with hematuria or urinary retention. A colonoscopy was performed in three-fourth of patients and was within normal limits. Three patients underwent cystoprostatectomy and 1 had a transurethral resection of the prostate. On gross examination, only tumor formed a 3.5 cm tan-gray, ulcerated, friable, and necrotic mass and 2 displayed either irregular red granular or thickened areas within the prostatic urethra. Abundant extracellular mucin pools dissecting the prostatic stroma were present in all tumors, with clusters of tumor cells floating in the mucin. The mucin pools were lined by pleomorphic pseudostratified columnar mucinous epithelium. Tumors were diffusely positive for CK20, CDX2 (4/4), and AMACR (2/2); they focally expressed CK7 (2/4), and lacked nuclear ß-catenin expression (3/3). PSA, PSAP, NKX3.1, p63, and GATA3 were negative in the tumors tested. Among the 3 patients who underwent radical surgery, 2 had stage 2 tumors (confined to the prostatic urethra and prostate), and 1 had a stage 3 tumor, with seminal vesicle involvement. All 4 patients were alive without disease with a mean follow-up of 4.9 years. In conclusion, brachytherapy-associated mucinous adenocarcinoma of the prostatic urethra displays intestinal-type features as its non-radiation-related counterpart. It appears to lack a villous adenoma component, displays a different immunohistochemical profile with diffuse CK20 and CDX2 positivity, and is associated with lower stage and less aggressive behavior.

Immunohistochemical expression of CK20, CK7, and CDX2 in colorectal carcinoma in correlation with pathomorphological characteristics.

INTRODUCTION: Colorectal carcinoma is the third most common cancer worldwide. The usual immunophenotype of colorectal adenocarcinoma is CDX2 positive, CK20 positive, and CK7 negative. Aberrant expression is reported in a variety of colorectal carcinomas but its relation to morphological variables and survival data is still unclear.

Anti-CK7/CK20 Immunohistochemistry Did Not Associate with the Metastatic Site in TTF-1-Negative Lung Cancer.

Anti-CK7 and anti-CK20 immunohistochemistry is sometimes used to establish a diagnosis of primary lung cancer. We performed a retrospective study on the value of anti-CK7 and anti-CK20 immunohistochemistry in 359 biopsies of patients with suspected lung carcinoma in order to assess the usefulness of these antibodies in the evaluation of lung tumors in biopsies. Our results showed TTF-1 positivity in 73.3% of patients. EGFR mutations and ALK rearrangements were significantly different between TTF-1 positive and TTF-1 negative tumors (p < 0.001 and p = 0.023, respectively). Our results show a significant difference (p < 0.001) between TTF-1 positive and TTF-1 negative carcinomas with a median survival of 21.97 months (CI95% = 17.48−30.9 months) and 6.52 months (CI95% = 3.34−10.3 months), respectively. In the group of TTF-1 negative patients, anti-CK7 and CK20 immunohistochemistry was performed in 70 patients and showed CK7+/CK20- staining in 61 patients (87.1%), CK7-/CK20- in 4 patients (5.7%), CK7+/CK20+ in 3 patients (4.3%), and CK7-/CK20- in 2 patients (2.8%). No specific or molecular pattern was found in these groups of CK7/CK20 combinations. In total, this work brings arguments concerning the uselessness of anti-CK7/CK20 immunohistochemistry in the case of suspicion of primary lung cancer in biopsies.