Return to play following craniotomy for non-traumatic brain lesions.

Objective: Return to play (RTP) decisions after cranial surgery are important to patients. Most published data relate to RTP following sports-related brain injury. This study investigated factors that influence neurosurgical RTP decision-making following craniotomy for non-traumatic brain lesions. Methods: A patient scenario-based survey was distributed to U.S. and Europe-based neurosurgeons via the American Association of Neurological Surgeons/Congress of Neurological Surgeons Tumor Section and the European Association of Neuro-Oncology. From one core patient scenario, 5 further scenarios were developed involving patients of varying age, sport preference, tumor pathology, and craniotomy approach. Respondents provided RTP recommendations and factors important in forming these recommendations. Results: Forty-one responses were received; Europe (48%), U.S. (37%). The most commonly cited factors influencing RTP decision-making across scenarios were symptomatic recovery (85.4%), resolution of blood and/or air on imaging (43.4%), and patient demand (31.7%). The sports with the longest average RTP timeline were boxing (10.3 months), rugby (8.7 months), and American football (8.5 months) in the core patient scenario. Twenty-nine percent of neurosurgeons requested neuroimaging before determining RTP recommendations in this scenario, more commonly in America than Europe (46.7% and 5.0% respectively, p = .006). Conclusions: Although limited by sample size, the data provides a foundation to support development of a systematic approach to RTP decision-making following craniotomy for brain lesions of non-traumatic etiology. Future work to develop consensus guidelines will benefit from objective data about outcomes, particularly in relation to repeat imaging prior to RTP.

A case of intraductal papillary neoplasm of the bile duct suspected to be of peribiliary glands origin.

Peribiliary glands are complex lobular structures containing mucus and serous glands, distributed along the extrahepatic and intrahepatic bile ducts. In this report, we describe a case of intraductal papillary neoplasm of the bile duct suspected to be of peribiliary glands origin. The patient was an 80-year-old man who was referred to our hospital for a hepatic mass. On further examination, a 38 × 34 mm cystic lesion with papillary growth was found in S1/4. Because the lesion was extensively bordered by both hepatic ducts and the connection was unclear, it was difficult to determine the extent of hepatic resection. To confirm the location, a peroral cholangioscopy was performed. The connection with the cyst was detected in the right hepatic duct and a villous tumor mucosa protruded through the conduit lumen. Since we found that the lesion communicated with the right hepatic duct, a right hepatectomy was subsequently performed. The postoperative pathological diagnosis was an intraductal papillary neoplasm of the blie duct with associated invasive carcinoma. The postoperative course was good, and the patient experienced no recurrence.

Updated techniques and evidence for endoscopic ultrasound-guided tissue acquisition from solid pancreatic lesions.

Endoscopic ultrasound-guided tissue acquisition (EUS-TA), including fine-needle aspiration (EUS-FNA) and fine-needle biopsy (EUS-FNB), has revolutionized specimen collection from intra-abdominal organs, especially the pancreas. Advances in personalized medicine and more precise treatment have increased demands to collect specimens with higher cell counts, while preserving tissue structure, leading to the development of EUS-FNB needles. EUS-FNB has generally replaced EUS-FNA as the procedure of choice for EUS-TA of pancreatic cancer. Various techniques have been tested for their ability to enhance the diagnostic performance of EUS-TA, including multiple methods of sampling at the time of puncture, on-site specimen evaluation, and specimen processing. In addition, advances in next-generation sequencing have made comprehensive genomic profiling of EUS-TA samples feasible in routine clinical practice. The present review describes updates in EUS-TA sampling techniques of pancreatic lesions, as well as methods for their evaluation.

Rare case of mantle cell lymphoma of the lacrimal sac

ABSTRACT Mantle cell lymphoma of the ocular and periorbital regions is extremely rare but should be considered in the differential diagnosis of lesions affecting the periorbital tissues. In this study, we present a rare case of mantle cell lymphoma of the lacrimal sac in a 65-year-old male presenting with a mass in the lacrimal sac region and epiphora. After clinical examinations and imaging studies, the mucocele was misdiagnosed. Considering the unexpected findings during external dacryocystorhinostomy, a frozen biopsy was performed, which confirmed the diagnosis of lymphoma.

MiNEN of base of tongue - first case report in literature.

INTRODUCTION: Mixed neuroendocrine and non-neuroendocrine neoplasms (MiNENs) refer to a heterogenous group of rare neoplasms which is usually composed of a neuroendocrine population which is either well differentiated and more frequently poorly differentiated along with a non-neuroendocrine component, each of the above accounting for at least 30% of the tumour population. It is most commonly seen in the gastro-entero-pancreatic tract. MiNENs have an aggressive behaviour due to its high grade neuroendocrine component and have poor prognosis. This is the first case reported in literature of a MiNEN in the oropharynx. CASE REPORT: 69 year old male patient with no co morbidities presented to the outpatient department with complains of odynophagia for 1 month. He had history of neoadjuvant chemotherapy followed by transoral robotic surgery (TORS) with right selective neck dissection (SND) done in 2019 for carcinoma base of tongue. On flexible laryngoscopy, an ulcerative lesion was noted over the left base of tongue. Although PET scan done showed no significant abnormalities. Biopsy from the lesion showed features of poorly differentiated carcinoma along with morphological features of poorly differentiated neuroendocrine carcinoma (small cell carcinoma). He was planned for upfront surgery (TORS with left SND). Post operatively recovery was uneventful and patient was on ryles tube feed for 12 days. Final histopathology report showed features of mixed neuroendocrine non neuroendocrine neoplasm. He has been on follow up for 1 year with no features of recurrence. CONCLUSION: MiNEN is an aggressive tumour which has poor prognosis and is most commonly located in the gastrointestinal tract. This is the first case reported in oropharynx who has been successfully treated and has been on follow up.

Aberrant CD45 Immunoreactivity in Neuroendocrine Neoplasms: A Diagnostic Pitfall-Report of 10 Specimens and Clinical Recommendations.

Leukocyte common antigen (LCA), or CD45, is classically thought of as a leukocyte-exclusive protein, and as such, CD45 immunohistochemistry (IHC) is often used as a key differentiator between non-Hodgkin lymphomas (NHLs) and morphologically similar neuroendocrine neoplasms (NENs). Herein, we report our experience regarding aberrant CD45 immunoreactivity in a series of NENs. A natural language search was used to retrieve desired archival patient files. All prior NENs which had a positive neuroendocrine diagnosis or IHC results (synaptophysin, chromogranin, CD56, and/or neuron-specific enolase), as well as CD45 staining performed, were reviewed for possible CD45 positivity (n = 686). Among these 686 NENs, 10 were aberrantly positive for CD45 staining. CD45 showed nuclear, cytoplasmic, and/or membranous staining in tumor cells. The significance of such staining is unclear. Albeit for a minority of patients, pathologists should be aware that NENs may aberrantly stain with CD45 and thereby pose a diagnostic pitfall. Therefore, broadening routine IHC panels is recommended to differentiate NENs more clearly from NHLs.

Minimal change glomerular disease associated with solid neoplasms: a systematic review.

BACKGROUND: Paraneoplastic minimal change disease (MCD) has been associated with hematological malignancies, whereas solid malignancies are commonly associated with membranous glomerulonephritis. In this systematic review of the literature, we describe the clinical features, treatment and outcome of MCD associated with solid neoplasms. METHODS: We performed a systematic review of the MEDLINE, COCHRANE, EMBASE and SCOPUS databases, including case reports of adult patients with biopsy-proven MCD and solid malignancy, without language or time restrictions. RESULTS: Sixty-seven papers were included, presenting 86 cases with a mean age of 57.8 ± 14.7 years; 41.0% were women. Nephrotic syndrome was the initial presentation in 96.2% of patients; 67.2% had kidney function impairment, and 21.2% required kidney replacement therapy. The most frequent malignancies were malignant thymoma (34.9%), kidney (14.0%), lung (12.8%), and gastrointestinal tumors (12.8%). In 40.7% of cases, the neoplasm diagnosis preceded MCD by 33.8 ± 46.1 months, while in 31.4%, it followed diagnosis of MCD by 12.4 ± 22.6 months. In 27.9%, the neoplasm and kidney disease were diagnosed simultaneously. Immunosuppressive therapy was started in 79.1% of cases and tumor-specific treatment in 83.7%. Remission of MCD was achieved in 80.2% of patients: 38.2% responded to immunosuppressive treatment alone and 29.6% to oncological treatment alone. CONCLUSIONS: The association between MCD and solid neoplasms is well-documented. Immunosuppressive therapy alone induced nephrotic syndrome remission in over one-third of cases; most others responded to tumor-specific treatment. Solid tumor screening should be considered in MCD independently of the steroid response, though more data on solid tumor-associated MCD prevalence are needed for a definitive statement. PROSPERO TRIAL REGISTRATION NUMBER: CRD42024521854.

[Diagnosis and management of POEMS syndrome].

POEMS syndrome is a plasma cell neoplasm that presents with peripheral neuropathy, organomegaly, fluid retention, skin manifestations, osteosclerotic lesions, and λ-type M-proteinemia. The pathogenesis of POEMS syndrome is poorly understood, as the genetic profile of plasma cells in POEMS syndrome differs from that of myeloma. In most cases, POEMS syndrome is difficult to distinguish from chronic inflammatory demyelinating polyneuropathy (CIDP). Consequently, it is essential not to miss characteristic signs of POEMS syndrome such as M-protein, VEGF, pleural effusion, and osteosclerotic lesions. Novel agents for myeloma, such as thalidomide, lenalidomide, and bortezomib, are effective. For younger patients, these agents followed by autologous transplantation with high-dose melphalan is the standard of care. More relapses are now being reported in results of long-term observation, and treatment strategies for relapsed disease must be established.

[GATA factor-related hematopoietic neoplasms].

GATA1, GATA2, and GATA3, collectively known as hematopoietic GATA factors, play a central role in the transcription factor network that governs hematopoietic homeostasis. Dysfunction of these factors leads to various hematopoietic disorders. Aberrant function of GATA1 factor, crucial in erythrocyte and megakaryocyte differentiation, not only causes anemia and thrombocytopenia, but also triggers erythroid leukemia and acute megakaryoblastic leukemia. Similarly, GATA2 factor expression is dynamic in the hematopoietic hierarchy, and dysfunction of GATA2 factor contributes not only to dysfunction of the myeloid and lymphoid lineages but also to the development of diverse hematopoietic neoplasms such as myelodysplastic syndromes, acute myeloid leukemia, and myeloproliferative neoplasms. GATA3, critical for T-lymphocyte differentiation, is relevant to lymphocytic leukemia. This review discusses hematopoietic disorders caused by aberrant GATA transcription functions, with a particular emphasis on hematopoietic malignancies.

Pleomorphic Lobular Carcinoma In Situ Composed of Signet-Ring Cells Mimicking Ductal Carcinoma In Situ with A Papillary Pattern: A Case Report.

While some forms of invasive or in situ carcinoma of the breast may be partly composed of signet-ring cells, signet-ring cells rarely become a prominent feature of pleomorphic lobular carcinoma in situ (LCIS). We report a rare example of pleomorphic LCIS composed predominantly of signet-ring cells with a papillary pattern mimicking ductal carcinoma in situ (DCIS). A 58-year-old woman presented with a mass in the left breast detected by ultrasonography. Fourteen years previously, the patient underwent right breast-conserving surgery for invasive breast carcinoma of no special type. Ultrasonography revealed an irregular parallel, angular hypoechoic mass measuring 1.5 cm in the left breast. An ultrasound-guided core needle core biopsy was conducted. Microscopically, the lesion was composed of epithelial cells supported by a fibrovascular stroma. The majority (> 70%) of the lesional cells between the fibrovascular stalks showed signet-ring cell features. Some of the nuclei of the signet-ring cells showed intermediate-grade atypia. A mucicarmine stain showed intracytoplasmic mucin in the signet-ring cells. Immunohistochemistry for E-cadherin was negative in the tumor cells. After surgical excision, the final diagnosis was a pleomorphic LCIS. To our knowledge, there have been no previous reports of pleomorphic LCIS consisting primarily of signet-ring cells with a papillary pattern.

Real-world treatment patterns, survival outcomes, and health care resource utilization for locally advanced or metastatic urothelial carcinoma in Spain.

PURPOSE: Real-world evidence on locally advanced or metastatic urothelial carcinoma (la/mUC) management in Spain is limited. This study describes patient characteristics, treatment patterns, survival, and health care resource utilization (HCRU) in this population. METHODS/PATIENTS: This retrospective observational study included all adults with a first diagnosis/record of la/mUC (index date) from January 2015 to June 2020 at nine university hospitals in Spain. Data were collected up to December 31, 2020 (end of study), death, or loss to follow-up. Patient characteristics, treatment patterns, median overall survival (OS) and progression-free survival (PFS) from index date (Kaplan-Meier estimates), and disease-specific HCRU were described. RESULTS: Among 829 patients, median age at diagnosis was 71 years; 70.2% had ≥ 1 comorbidity, and 52.5% were eligible for cisplatin. Median follow-up was 12.7 months. Most (84.7%) patients received first-line systemic treatment; of these, 46.9% (n = 329) received second-line and 16.6% (n = 116) received third-line therapy. Chemotherapy was the most common treatment in all lines of therapy, followed by programmed cell death protein 1/ligand 1 inhibitors. Median (95% confidence interval) OS and PFS were 18.8 (17.5-21.5) and 9.9 (8.9-10.5) months, respectively. Most patients required ≥ 1 outpatient visit (71.8%), inpatient admission (56.6%), or emergency department visit (56.5%). CONCLUSIONS: Therapeutic patterns were consistent with Spanish guideline recommendations. Chemotherapy had a role in first-line treatment of la/mUC in Spain during the study period. However, the disease burden remains high, and new first-line treatments recommended in the latest European guidelines should be made available to patients in Spain.

Blastic plasmacytoid dendritic cell neoplasm: Two case reports.

BACKGROUND: Blastic plasmacytoid dendritic cell tumor (BPDCN) is a rare and highly invasive lymphohematopoietic tumor that originates from plasmacytoid dendritic cells. BPDCN has an extremely poor prognosis. Skin lesions are usually the first manifestation of BPDCN, although the tumor may also invade the bone marrow, lymph nodes, peripheral blood, and other parts of the body, leading to several other manifestations, requiring further differentiation through skin biopsy and immunohistochemistry. CASE SUMMARY: In the present paper, the cases of 2 patients diagnosed with BPDCN are discussed. The immunohistochemistry analysis of these 2 patients revealed positivity for CD4, CD56, and CD123. Currently, no standard chemotherapy regimen is available for BPDCN. Therefore, intensive therapy for acute lymphoblastic leukemia was applied as the treatment method for these 2 cases. CONCLUSION: Although allogeneic bone marrow transplantation could be further effective in prolonging the median survival the ultimate prognosis was unfavorable. Future treatment modalities tailored for elderly patients will help prolong survival.

Histopathological features of subcutaneous and cutaneous mast cell tumors in dogs.

BACKGROUND: Mast cell tumors (MCTs) are the most common malignant skin neoplasms in dogs. In the past, the distinction between cutaneous MCTs (cMCTs), originating from the dermis, and subcutaneous MCTs (scMCTs), originating from the subcutaneous tissue, was not made. Histopathological differentiation, including grading, is important for prognosis. However, the Patnaik and Kiupel grading systems were proposed for cMCTs only. The objective of our study was to describe and compare the signalment of dogs with scMCTs and cMCTs and histopathological features, anticipating similarities in both groups. Data of dogs histologically diagnosed with scMCTs or cMCTs between September 2020 and July 2023 were analyzed retrospectively. Signalment, tumor location, histopathological features, completeness of removal and lymph node status were recorded. RESULTS: Data on 305 scMCTs and 1291 cMCTs were collected. Breed distribution was different between scMCTs and cMCTs (P < 0.0001). Mitotic count (MC) was not different between scMCTs (1.63) and cMCTs (1.58) (P = 0.8490). Compared to cMCTs, scMCTs more often had anisokaryosis, bizarre nuclei and multinucleation. Kiupel high grade was more often assigned to scMCTs (51/292, 17.5%) than cMCTs (154/1291, 11.9%) (P = 0.009). The odds of MCTs being assigned a high grade in scMCT was 1.578 higher than in cMCTs (95% confidence interval [1.116-2.232]). CONCLUSIONS: Histopathological differences between scMCTs and cMCTs were observed. A Kiupel high grade was more often assigned to scMCTs than cMCTs. Whether these histopathological findings correlate with clinical outcome has to be established in additional studies.

Surgical management of pancreatic neoplasms in children: a single-institution experience over 15 years.

Introduction: Pancreatic neoplasms are rare among children and very few studies have reported on surgical outcomes for pediatric pancreatic neoplasms. Therefore, we aimed to describe patient and tumor characteristics and report on the surgical outcomes of pediatric pancreatic neoplasm. Methods: In this retrospective single-center study, we reviewed and analyzed the data of patients who underwent surgery for pediatric pancreatic neoplasms at Severance Children's Hospital between January 2007 and December 2022. Clinical data including demographics, surgical procedures, and postoperative and long-term outcomes were evaluated. Results: A total of 28 patients underwent surgical treatment for pancreatic neoplasms with a median age of 11.7 years (range: 0.4-17.8). The most common histological diagnosis among benign tumors was solid pseudopapillary neoplasm (SPN), which occurred in 20 patients (71.4%). This was followed by a mucinous cyst, nesidioblastosis, pseudocyst, duplication cyst, and benign cyst, each occurring in one patient (3.5%). Regarding malignant tumors, pancreatoblastoma, solid pseudopapillary carcinoma, and malignant pheochromocytoma were noted in one patient each (3.5%). Tumor locations included the head in 4 patients (14.2%), the body in 7 (25%), and the tail in 16 (57.1%), and was diffuse in 1 (3.5%). The most common surgical resection range was distal pancreatectomy, found in 22 patients (78.5%), followed by pylorus-preserving pancreaticoduodenectomy, found in 2 (7.2%); duodenum-preserving pancreatic resection, central pancreatectomy, tumor enucleation, and near-total pancreatectomy were performed in one patient each (3.5%). Overall, 4 patients developed grade B or C postoperative pancreatic fistulas, and 1 experienced postoperative mortality due to uncontrollable bleeding. The mean follow-up period was 6.1 years (range: 1-15.6 years), during which no significant impact on growth after surgery was detected. Among the 20 patients with SPN, tumor rupture occurred in 4 (20%), among whom 2 experienced tumor recurrences. Conclusions: Histological diagnosis of benign tumors was predominant in this case series and various extents of surgical resection were performed. Surgical treatment for pediatric pancreatic neoplasms appears to be safe and effective. However, considering the long-term prognosis of these patients, it is essential to determine the appropriate extent of surgical resection based on the location of the tumor.

Neurofibromatosis to neoplasia transition: a rare case report of spindle cell malignant peripheral nerve sheath tumor with literature review.

Introduction and importance: Malignant peripheral nerve sheath tumor (MPNST) is a rare and aggressive soft tissue malignant tumor. MPNST in the spinal canal is rarely seen except in cases of neurofibromatosis type 1. However, a long-segment extradural spinal malignant spindle cell neoplasm has not been reported in the current literature. Case presentation: We present the first reported case of spinal malignant spindle cell neoplasm extended along the spine. The detected lesion is responsible for compressing various segments of the spinal cord, causing thinning of the cord and secondary stenosis of the spinal canal, leading to a condition known as multisegment compression myelopathy. Clinical discussion: MPNSTs are typically detected late due to nonspecific symptoms, with a higher incidence in extremities and a notable occurrence in unusual locations. Diagnosis relies on MRI and histopathology, with S_100 positivity as a neural marker. MPNSTs can arise from neurofibromas or Schwann cells, with a significant portion resulting from TP53 mutations or secondary to radiation exposure. Conclusion: This case stands out due to its unique presentation, characterized by a predominantly spindle cell morphology with certain epithelioid features. It is imperative to recognize this condition for an accurate diagnosis, emphasizing the spindle cell-type MPNST and highlighting its exceptionally poor prognosis.

Different Etiologies of Dilated Pancreatic Duct Based on Endoscopic Ultrasonography Findings.

Background: Pancreatic duct (PD) dilation could be presented in both benign and malignant diseases. Endoscopic ultrasonography (EUS) is a sensitive modality that provides both structural assessment and tissue sampling. This study aims to explore the importance of PD dilation as a potential indicator related to various pancreatobiliary pathologies identified via EUS. Methods: Among 3109 subjects who underwent EUS, 599 had evidence of dilated PD and met the inclusion criteria of this retrospective study. Also, the patients underwent EUS fine needle aspiration (EUS-FNA) to evaluate the etiology when required. All data were extracted from patients' medical records to perform statistical analysis. Results: The study sample revealed 64% being male with a median age was 65-years. Pancreatic adenocarcinoma was the most common etiology diagnosed in 236 patients (39.4%), followed by sphincter of Oddi dysfunction (SOD) in 13% of subjects. Ampullary carcinoma, common bile duct stone, and cholangiocarcinoma were found at 9.5%, 8.8%, and 6.8%, respectively. Abdominal pain was the most common symptom seen in 440 (73.4%) patients. Opium consumption was reported in 170 (28.4%) subjects. Opium consumption was significantly more prevalent in patients with SOD (P<0.05). Conclusion: We suggest that PD dilation could be associated with a wide range of pancreaticobiliary pathologies, especially pancreatic neoplasms. In this regard, PD dilation should be considered as a crucial indicator of pancreatic neoplasm despite it may be associated with no clear etiologies.

Neuroendocrine tumor mimicking a recalcitrant vocal fold granuloma: Appearances can be deceiving.

Posterior glottic lesions resembling granulomas unresponsive to conservative treatment should raise suspicion of a neoplastic condition. Although surgery is rarely recommended for arytenoid granulomas due to their high recurrence rate, histological evaluation is mandatory in cases of uncertain diagnosis. Clinicians should be aware that, although very rare, a laryngeal neuroendocrine tumor occurring in the posterior glottis can mimic the appearance of an idiopathic granuloma, presenting a diagnostic challenge.

Clinicopathological features and surgical treatments of intraductal papillary neoplasm of the bile duct: a case report and literature review.

Intraductal papillary neoplasm of bile duct (IPNB), as a precancerous lesion of cholangiocarcinoma, is a rare biliary tract tumor. A 66-year-old female patient was found to have a bile duct mass by routine examination. The liver function tests and tumor markers were normal. Imaging findings revealed a 2.6 cm mass in the common hepatic duct, accompanied by dilatation of both intrahepatic and extrahepatic bile ducts. The patient underwent open extrahepatic bile duct resection, cholecystectomy and Roux-en-Y hepaticojejunostomy. We also conducted a literature review to summarize the clinicopathological features and surgical treatments of IPNB.

Comparative Study of Gleason 7 (3+4) and (4+3) Prostatic Adenocarcinomas with Prog-nostic Criteria and Immunohistochemical Profiles of AMACR, PSA and Ki-67.

BACKGROUND: To compare Gleason 7 (3+4) and (4+3) prostatic adenocarcinoma (PC) with different prognostic criteria through immunohistochemical analysis with anti-PSA, anti-Ki 67 and anti-AMARC antibodies. METHODS: We analyzed 221 surgical specimens from patients between 40 and 86 years-old (mean=63) with PC. The immunohistochemical study was performed with anti-PSA, anti-Ki 67 and anti-AMARC. The microscopic fields were photographed with an Olympus DP70 digital camera coupled to an Olympus BX51 microscope and archived in TIFF. Proportion and intensity criteria were used to quantify the anti-PSA antibody and for the anti-Ki 67 antibody, the quantification by similarity of this antibody in breast carcinomas. Anti-AMACR protein expression was based on four scores: negative, weak, moderate and strong. The statistical analysis was performed with the Graph Pad Prism 5 program. RESULTS: In the Gleason score 7 (3+4) we had 91.72% in pT2 and 8.27% in the pT3 group; 8.27% recurrences, of which 90.90% in the pT2 group. In the Gleason score 7 (4+3) we had 77.27% in the pT2 group and 22.72% in the pT3 group and 10.22% of relapses, of which 66.66% in the pT2 group and 33.33% in the pT3 group. In 6.81% of cases there was an increase in the anti-Ki 67 index and in 2.27% of the cases, there was an increase in the immunoexpression of anti-p53 when comparing Gleason score 7 (3+4) with Gleason score 7 (4+3). CONCLUSION: Our study confirmed differences in the Gleason score 7 (3+4) and Gleason score 7 (4+3) of PC when comparing prognostic criteria. Anti-Ki 67 and anti-PSA antibody immunostaining showed a positive correlation as the Gleason score 7 increased from (3+4) to (4+3).

Evaluation of epithelial-to-mesenchymal transition and Ki-67 index in aggressive papillary thyroid cancer.

OBJECTIVES: The present study aims to characterize immunohistochemical features of markers associated with Epithelial-Mesenchymal Transition (EMT) and proliferative activity that could lead to death in Papillary Thyroid Cancer (PTC). METHODS: Clinical data and tumor material were retrospectively collected. The patients were separated into death from PTC (Group 1), metastatic cases with indolent behavior (Group 2) and non-metastatic indolent PTC (Group 3). Immunohistochemical assessment of E-cadherin, ß-catenin, Vimentin, ZEB-1 and Ki-67 was performed in each tumor and a semiquantitative estimation of the percentage of expression was fulfilled on the best marking area at high of the tumor invasion front. RESULTS: 31 patients were included, 15 that died from PTC (Group 1), 6 in Group 2 and 10 in Group 3. The proliferative marker Ki-67 showed a significant difference in its expression in the tumor invasion front between the groups, specifically between groups 1 and 3 (p = 0.006). On the other hand, EMT-related immunohistochemical markers did not show significant difference in their percentage of expression, since loss of E-cadherin, ß-catenin and Vimentin was observed in most cases at the invasion front. CONCLUSION: Patients that died from PTC had a significantly higher Ki-67 labelling index compared to patients with indolent disease (cutoff of 11%). Ki-67 may have a role as a prognostic marker and could be considered for routine use in PTC.