A case report on rare co-occurrence of invasive ovarian mucinous adenocarcinoma, unilateral renal agenesis, and bicornuate uterus: is it a new triad?

BACKGROUND: Concomitant invasive ovarian mucinous adenocarcinoma, unilateral renal agenesis and bicornuate uterus is a rare combination. Unilateral renal agenesis has been associated with genital anomalies, such as unicornuate and bicornuate uterus. Furthermore, a wealth of studies has reported the association between unicornuate uterus and ovarian anomalies, such as the absence of an ovary or ectopic ovaries, but rarely has there been a combination of the three to the best of our knowledge. The present case report is the first case presentation with a combination of the three syndromes: ovarian mucinous tumor, unilateral renal agenesis, and bicornuate uterus. CASE PRESENTATION: We report the case of a 17-year-old who presented with abdominal distension. On examination, a CT scan revealed a large multicystic abdominal mass on the right side, with an absence of the right kidney while the left kidney was normal in size, appearance, and position. Intraoperatively, massive blood-stained ascitic fluid was evacuated. Additionally, a large whitish polycystic intra-abdominal mass with mucus-like materials and solid areas was attached to the midpoint of the colon and the right ovary, with visible metastasis to the omentum. The uterus was bicornuate. The mass and omentum were taken for histopathology and a diagnosis of invasive ovarian mucinous cystadenocarcinoma with metastasis to the colon and omentum was made after a pathological report. CONCLUSIONS: The presence of these conditions in the same individual could potentially complicate medical management and fertility considerations. Thus, a need for a multidisciplinary medical team, including gynecologists, urologists, and oncologists, to address their unique needs and provide appropriate treatment and guidance. Further research and case studies are needed to better understand the possible association and implications of these rare co-occurring conditions.

Perioperative management of a patient with unexpectedly detected early-stage ovarian mucinous carcinoma combined with progressive bulbar paralysis: a case report and literature review.

BACKGROUND: Giant ovarian cysts (GOCs)complicated with progressive bulbar paralysis (PBP) are very rare, and no such literature about these cases have been reported. Through the diagnosis and treatment of this case, the perioperative related treatment of such patients was analyzed in detail, and early-stage ovarian mucinous carcinoma was unexpectedly found during the treatment, which provided reference for clinical diagnosis and treatment of this kind of diseases. CASE PRESENTATION: In this article, we reported a 38-year-old female patient. The patient was diagnosed with PBP 2 years ago. Examination revealed a large fluid-dominated cystic solid mass in the pelvis measuring approximately 28.6×14.2×8.0 cm. Carbohydrate antigen19-9(CA19-9) 29.20 IU/mL and no other significant abnormalities were observed. The patient eventually underwent transabdominal right adnexal resection under regional anesthesia, epidural block. Postoperative pathology showed mucinous carcinoma in some areas of the right ovary. The patient was staged as stage IA, and surveillance was chosen. With postoperative follow-up 1 month later, her CA19-9 decreased to 14.50 IU/ml. CONCLUSIONS: GOCs combined with PBP patients require a multi-disciplinary treatment. Preoperative evaluation of the patient's PBP progression, selection of the surgical approach in relation to the patient's fertility requirements, the nature of the ovarian cyst and systemic condition are required. Early mucinous ovarian cancer accidentally discovered after operation and needs individualized treatment according to the guidelines and the patient's situation. The patient's dysphagia and respiratory function should be closely monitored during the perioperative period. In addition, moral support from the family is also very important.

Single nucleotide polymorphism (SNP) chromosomal microarray as a diagnostic tool for mucinous tubular and spindle cell carcinoma: A validation study.

Mucinous tubular and spindle cell carcinoma (MTSCC) shows significant overlap with papillary renal cell carcinoma (PRCC), and harbor recurrent copy-number alterations (CNA). We evaluated 16 RCC with features suggestive of MTSCC using chromosomal microarrays. The cohort was comprised of 8 females and males, each, with an age range of 33-79 years (median, 59), and a tumor size range of 3.4-15.5 cm (median, 5.0). Half the tumors were high-grade (8/16, 50%) with features such as necrosis, marked cytologic atypia, and sarcomatoid differentiation, and 5/16 (31%) were high stage (≥pT3a). Three (of 16, 19%) cases had a predominant (>95%) spindle cell component, whereas 5/16 (31%) were composed of a predominant (>95%) epithelial component. Most cases (12/16, 75%) exhibited a myxoid background and/or extravasated mucin, at least focally. Twelve (of 16, 75%) cases demonstrated CNA diagnostic of MTSCC (losses of chromosomes 1, 4, 6, 8, 9, 13, 14, 15, and 22). In addition, 2 high-grade tumors showed loss of CDKN2A/B, and gain of 1q, respectively, both of which are associated with aggressive behavior. Three (of 16, 19%) cases, demonstrated nonspecific CNA, and did not meet diagnostic criteria for established RCC subtypes. One (of 16, 6%) low-grade epithelial predominant tumor (biopsy) demonstrated characteristic gains of 7, 17, and loss of Y, diagnostic of PRCC. MTSCC can be a morphologically heterogenous tumor. Our study validates the detection of characteristic chromosomal CNA for diagnostic use that may be useful in challenging cases with unusual spindle cell or epithelial predominant features, as well as in high-grade tumors.

Primary Vaginal Mucinous Adenocarcinoma of Intestinal Type-Clinical, Radiological and Morphological Aspects.

Background and Objectives: Neoplasms of the vagina are rare and account for 1-2% of all tumors of the female reproductive system. Primary neoplasms of the vagina are most often carcinomas originating from squamous or glandular epithelium. Of the primary glandular tumors, clear cell, endometrioid, and serous adenocarcinomas are the most common types, while mucinous and mesonephric types are very rare. Mucinous adenocarcinoma is histologically subclassified into endocervical and intestinal types. We add to the existing literature another case of an extremely rare gynecological neoplasm-primary vaginal mucinous adenocarcinoma (PVMAC) intestinal type associated with vaginal villous adenoma with high-grade dysplasia. We discuss the clinical, radiological and morphological features of this rare entity. Materials and Methods: We report a case of a 59-year-old woman with PVMAC intestinal type associated with vaginal villous adenoma with high-grade dysplasia. The patient was evaluated with a gynecological exam, and biopsy, curettage and tumor excision were performed. The positron emission tomography-computed tomography (PET/CT) scan, at the level of the pelvis, supported the primary location of the disease. Histological and immunohistochemical methods were applied. Results: The gynecological examination of the vagina revealed an exophytic polypoid mass with a diameter of 3 cm, located on the posterior wall, in the area of introitus vaginae. The PET/CT scan revealed a hypermetabolic malignant formation involving the vagina and anal canal, without evidence of pelvic and inguinal lymphadenopathy, and also, it excluded disease at sites other than the vagina. The histological and immunohistochemical investigations, as well as the clinical and radiological data, lent support to the diagnosis "primary vaginal mucinous adenocarcinoma intestinal type". Conclusions: PVMAC intestinal type is a rare gynecological pathology, which presents a serious challenge for oncogynecologists, radiologists and pathologists.

Metastatic mucinous adenocarcinoma from breast mimicking a pyogenic granuloma in the gingiva: a case report.

Mucin-producing adenocarcinomas (MAC) are an extremely rare, indistinct group of neoplasm having either a salivary gland origin or with prominent glandular component. The diagnosis is chiefly based on the histological aspect conjoined with immunohistochemical evaluation as clinico-radiographical features are non-specific. It can arise as a primary metastasis to soft tissues, most commonly from either lung, breast, kidney, or colon. This paper reports a 51-year-old woman with buccolingual gingival swelling having a final diagnosis of metastatic mucinous adenocarcinoma from the breast. A tissue biopsy was performed followed by immunohistochemistry that confirmed the diagnosis. They are extremely rare, making the diagnosis challenging as it may mimic a benign neoplasm. It accounts for approximately 1% of all oral malignant neoplasms having gingival propensity. The clinician should therefore take into account every diagnostic aspect while encountering such oral lesions to achieve proper patient welfare.

Immunohistochemical FAP Expression Reflects 68Ga-FAPI PET Imaging Properties of Low- and High-Grade Intraductal Papillary Mucinous Neoplasms and Pancreatic Ductal Adenocarcinoma.

Pancreatic intraductal papillary mucinous neoplasms (IPMNs) are grossly visible (typically > 5 mm) intraductal epithelial neoplasms of mucin-producing cells, arising in the main pancreatic duct or its branches. According to the current 2-tiered grading scheme, these lesions are categorized as having either low-grade (LG) dysplasia, which has a benign prognosis, or high-grade (HG) dysplasia, which formally represents a carcinoma in situ and thus can transform to pancreatic ductal adenocarcinoma (PDAC). Because both entities require different treatments according to their risk of becoming malignant, a precise pretherapeutic diagnostic differentiation is inevitable for adequate patient management. Recently, our group has demonstrated that 68Ga-fibroblast activation protein (FAP) inhibitor (FAPI) PET/CT shows great potential for the differentiation of LG IPMNs, HG IPMNs, and PDAC according to marked differences in signal intensity and tracer dynamics. The purpose of this study was to biologically validate FAP as a target for PET imaging by analyzing immunohistochemical FAP expression in LG IPMNs, HG IPMNs, and PDAC and comparing with SUV and time to peak (TTP) measured in our prior study. Methods: To evaluate the correlation of the expression level of FAP and α-smooth muscle actin (αSMA) in neoplasm-associated stroma depending on the degree of dysplasia in IPMNs, 98 patients with a diagnosis of LG IPMN, HG IPMN, PDAC with associated HG IPMN, or PDAC who underwent pancreatic surgery at the University Hospital Heidelberg between 2017 and 2023 were identified using the database of the Institute of Pathology, University Hospital Heidelberg. In a reevaluation of hematoxylin- and eosin-stained tissue sections of formalin-fixed and paraffin-embedded resection material from the archive, which was originally generated for histopathologic routine diagnostics, a regrading of IPMNs was performed by a pathologist according to the current 2-tiered grading scheme, consequently eliminating the former diagnosis of "IPMN with intermediate-grade dysplasia." For each case, semithin tissue sections of 3 paraffin blocks containing neoplasm were immunohistologically stained with antibodies directed against FAP and αSMA. In a masked approach, a semiquantitative analysis of the immunohistochemically stained slides was finally performed by a pathologist by adapting the immunoreactive score (IRS) and human epidermal growth factor receptor 2 (Her2)/neu score to determine the intensity and percentage of FAP- and αSMA-positive cells. Afterward, the IRS of 14 patients who underwent 68Ga-FAPI-74 PET/CT in our previous study was compared with their SUVmax, SUVmean, and TTP for result validation. Results: From 98 patients, 294 specimens (3 replicates per patient) were immunohistochemically stained for FAP and αSMA. Twenty-three patients had LG IPMNs, 11 had HG IPMNs, 10 had HG IPMNs plus PDAC, and 54 had PDAC. The tumor stroma was in all cases variably positive for FAP. The staining intensity, percentage of FAP-positive stroma, IRS, and Her2/neu score increased with higher malignancy. αSMA expression could be shown in normal pancreatic stroma as well as within peri- and intraneoplastic desmoplastic reaction. No homogeneous increase in intensity, percentage, IRS, and Her2/neu score with higher malignancy was observed for αSMA. The comparison of the mean IRS of FAP with the mean SUVmax, SUVmean, and TTP of 68Ga-GAPI-74 PET/CT showed a matching value increasing with higher malignancy in 68Ga-FAPI-74 PET imaging and immunohistochemical FAP expression. Conclusion: The immunohistochemical staining of IPMNs and PDAC validates FAP as a biology-based stromal target for in vivo imaging. Increasing expression of FAP in lesions with a higher degree of malignancy matches the expectation of a stronger FAP expression in PDAC and HG IPMNs than in LG IPMNs and corroborates our previous findings of higher SUVs and a longer TTP in PDAC and HG IPMNs than in LG IPMNs.

Neuroendocrine Marker Expression in Primary Non-neuroendocrine Epithelial Tumors of the Ovary: A Study of 551 Cases.

Expression of neuroendocrine (NE) markers in primary ovarian non-NE epithelial tumors has rarely been evaluated. The aim of our study was to evaluate the expression of the most widely used NE markers in these neoplasms and to determine any prognostic significance of NE marker expression. The cohort consisted of 551 primary ovarian tumors, including serous borderline tumors, low-grade serous carcinomas, high-grade serous carcinomas (HGSC), clear cell carcinomas, endometroid carcinomas, mucinous borderline tumors, and mucinous carcinomas. Immunohistochemical analysis was performed using antibodies against INSM1, synaptophysin, chromogranin, and CD56 on tissue microarray. Positivity for INSM1, synaptophysin, chromogranin, and CD56 was most frequently observed in mucinous tumors (48.7%, 26.0%, 41.5%, and 100%, respectively). The positivity for these NE markers was mostly restricted to nonmucinous elements distributed throughout the tumor. The mucinous borderline tumor and mucinous carcinomas groups had similar proportions of positivity (mucinous borderline tumor: 53%, mucinous carcinomas: 39%). In the other tumor types, except for HGSC, there was only focal expression (5%-10%) or negativity for NE markers. HGSC showed high CD56 expression (in 26% of cases). Survival analysis was only performed for CD56 in HGSC as this was the only group with sufficient positive cases, and it showed no prognostic significance. Except for mucinous tumors, expression of NE markers in non-NE ovarian epithelial tumors is low. CD56 expression in HGSC occurs frequently but is without diagnostic or prognostic value.

TP53 as a Diagnostic Aid in the Distinction of Ovarian Mucinous Borderline Tumors From Mucinous Carcinoma.

Ovarian mucinous borderline tumors (MBTs) are clinically managed as benign neoplasms while the management of ovarian mucinous carcinomas (MC) is dependent on tumor stage. Despite the standardization of sampling of ovarian mucinous neoplasms, limited interobserver reproducibility between MBT and MC persists. Based on our recent finding that abnormal TP53 expression is associated with unfavorable outcome in MBT, we hypothesized that TP53 status might improve the reproducible distinction of MBT from MC. A virtual slide set of 85 consecutive ovarian mucinous neoplasms received at a single institution, with each case represented by 3 full sections, were reviewed by 3 pathologists in 2 iterations. The initial assessment was based solely on morphologic review, while the second iteration was performed with knowledge of TP53 status. The reproducibility of a trinary categorization (MBT, MBT with intraepithelial carcinoma [IEC], MC) significantly improved from a κ of 0.60 based on the initial morphologic assessment to a κ of 0.76 (t-test, P =0.0042) after consideration of TP53 immunohistochemistry (IHC) results. Six out of 85 patients died of disease, and in 2 of them, at least 1 pathologist assessed MBT with IEC and not MC even after integration of TP53 IHC. With the integration of TP53 IHC, substantial interobserver agreement for MBT and MC can be reached, particularly in cases with an uncertain degree of confluent growth. TP53 IHC can also be used to highlight and support the presence of IEC in MBT, however, discordances remained in 2 cases with adverse outcome.

Adenocarcinoma arising from a chronic perianal fistula in a Crohn's disease patient: case report and review of the literature.

Crohn's disease patients frequently develop perianal fistulas during their life. They are also at higher risk to develop cancers. Rarely, those cancers appear within a prior chronic fistula. The main types are adenocarcinoma mostly mucinous and squamous cell carcinoma. They are generally discovered at an advanced stage with a poor prognosis because symptoms are generally the same as those of the fistula itself. Regular follow-up of chronic fistulas is then important for an early diagnosis as well as histological analysis of the fistula during surgery. There is no consensus on the ideal treatment but abdominoperineal resection is the corner stone with or without neo or adjuvant chemo-radiotherapy. This paper presents a rare case of mucinous adenocarcinoma in a chronic perianal fistula in a Crohn's disease female and provides a review of the literature.

Primary Mucinous Carcinoma of Skin: A Rare Cutaneous Neoplasm. Clinicopathologic Features, Differential Diagnoses, and Review of Literature.

ABSTRACT: Primary mucinous carcinoma of the skin (PMCS) is a rare malignant neoplasm of sweat gland origin, with an incidence of 0.07 per million. Histologically, it may be difficult to differentiate it from metastatic mucinous carcinomas of the skin. A case of PMCS is reported here in a 59-year-old woman who presented with a lesion on the right lower eyelid. Histological examination revealed features of mucinous adenocarcinoma. The main differential diagnosis was metastatic mucinous adenocarcinoma; however, the lack of colorectal and lung markers and the presence of focal in situ components were consistent with the diagnosis of PMCS. PMCS and breast mucinous carcinoma share immunohistochemical markers, such as GCDFP-15 and mammaglobin; however, focal in situ component with the presence of myoepithelial cells in the tumor ruled out metastatic mucinous carcinoma of breast origin. The subsequent mammograms did not reveal any breast lesions. Colonoscopy did not show any evidence of colonic malignancy, and imaging studies (CT scan) did not show any evidence of neoplasm in the body. These findings were in keeping with a diagnosis of PMCS. The present case emphasizes the importance of clinicopathological correlation, histopathology, and immunohistochemistry in the accurate diagnosis of PMCS and summarizes the literature on these rare cutaneous neoplasms.

[Diagnostics and treatment of intraductal papillary mucinous pancreas neoplasm].

A clinical case of a 71-year-old patient with intraductal papillary mucinous neoplasia (IPMN) is presented. The diagnosis was established using endoscopic retrograde cholangiopancreatography, magnetic resonance imaging, computed tomography. Asymptomatic course, absence of pain syndrome, obstruction, exocrine and endocrine pancreatic failure, relatively satisfactory general health, but the presence of structural changes: an increase cyst in the head of the pancreas measuring 27×23 mm, expansion of the main pancreatic duct up to 13 mm raised doubts about the choice of treatment tactics, the need for surgical intervention. To exclude the risk of malignancy and the choice of treatment tactics, a fine-needle aspiration biopsy was performed, a cytological examination of the material, an expert opinion determined the scope of the surgical intervention. IPMN is a rather rare tumor of the pancreas. For a long time, IPMN flow "under the guise" of chronic pancreatitis. Depending on the type of degree of dysplasia and invasiveness of IPMN, the tactics of treatment and the volume of surgical intervention are determined. High-tech methods provide high information content in the diagnosis of IPMN. But only a morphological study allows you to determine the tactics of treatment.

Synergy of the microRNA Ratio as a Promising Diagnosis Biomarker for Mucinous Borderline and Malignant Ovarian Tumors.

Epithelial ovarian cancers (EOCs) are a heterogeneous collection of malignancies, each with their own developmental origin, clinical behavior and molecular profile. With less than 5% of EOC cases, mucinous ovarian carcinoma is a rare form with a poor prognosis and a 5-year survival of 11% for advanced stages (III/IV). At the early stages, these malignant forms are clinically difficult to distinguish from borderline (15%) and benign (80%) forms with a better prognosis due to the large size and heterogeneity of mucinous tumors. Improving their diagnosis is therefore a challenge with regard to the risk of under-treating a malignant form or of unnecessarily undertaking radical surgical excision. The involvement of microRNAs (miRNAs) in tumor progression and their potential as biomarkers of diagnosis are becoming increasingly recognized. In this study, the comparison of miRNA microarray expression profiles between malignant and borderline tumor FFPE samples identified 10 down-regulated and 5 up-regulated malignant miRNAs, which were validated by individual RT-qPCR. To overcome normalization issues and to improve the accuracy of the results, a ratio analysis combining paired up-regulated and down-regulated miRNAs was performed. Although 21/50 miRNA expression ratios were significantly different between malignant and borderline tumor samples, any ratio could perfectly discriminate the two groups. However, a combination of 14 pairs of miRNA ratios (double ratio) showed high discriminatory potential, with 100% of accuracy in distinguishing malignant and borderline ovarian tumors, which suggests that miRNAs may hold significant clinical potential as a diagnostic tool. In summary, these ratio miRNA-based signatures may help to improve the precision of histological diagnosis, likely to provide a preoperative diagnosis in order to adapt surgical procedures.

Endocrine Mucin-Producing Sweat Gland Carcinoma and Primary Cutaneous Mucinous Carcinoma: A Case Series.

Endocrine mucin-producing sweat gland carcinoma (EMPSGC) and primary cutaneous mucinous carcinoma (PCMC) are rare low-grade neoplasms thought to arise from apocrine glands that share many histological features and are proposed to be on a single histopathologic continuum, with EMPSGC as the in situ form that may progress to the invasive PCMC. Management involves a metastatic workup and either wide local excision (WLE) with greater than 5 mm margins or Mohs micrographic surgery (MMS) in anatomically sensitive areas. We present 2 cases of EMPSGC and 3 cases of PCMC and review their clinical and histopathologic features, differential diagnoses, and treatment.

Development and validation of a decision tree for distinguishing pulmonary adenocarcinomas with mucinous features and metastatic colorectal adenocarcinoma.

BACKGROUND: Diagnosis of mucinous carcinomas in the lung on transbronchial biopsy or fine-needle aspiration (FNA) samples can be difficult for the pathologist, because primary and metastatic tumors can have similar morphological, immunohistochemical, and molecular characteristics. Correct diagnosis is key to determine appropriate therapy and to distinguish primary from metastatic disease. This distinction often falls to the pathologist in patients with a history of mucinous adenocarcinoma of the colon. Despite its drawbacks, immunohistochemistry is often employed to help assign a primary site for mucinous adenocarcinomas in the lung. However, the published data in this regard is limited to studies that use only a handful of markers. METHODS: The authors examined the staining characteristics and heterogeneity of CK7, TTF-1, NapsinA, CK20, CDX2, and SATB2 in resection specimens of pulmonary adenocarcinomas with mucinous features and metastatic colorectal adenocarcinoma. RESULTS: Based on the heterogeneity, sensitivity, and specificity in this cohort, the authors developed a decision tree based on TTF-1, SATB2, CDX2, and CK7 to categorize tumors as primary or metastatic lesions. Validation of the decision tree in FNA specimens from the lungs and lung-draining lymph nodes showed 84% concurrence in cases from the lung and 100% concurrence in cases from the lymph node. In cases where the algorithm assigned a primary site, it was 95% accurate compared to the multidisciplinary diagnosis. CONCLUSIONS: This method holds promise in distinguishing primary versus metastatic lesions in resection, biopsy, and FNA samples from the lungs.

Clinical trajectory of intraductal papillary mucinous neoplasms progressing to pancreatic carcinomas during long-term surveillance: a prospective series of 100 carcinoma cases.

BACKGROUND: Trajectories of serological and morphological signatures have not been documented in pancreatic carcinogenesis related to intraductal papillary mucinous neoplasms (IPMNs). METHODS: Using a prospective cohort of 3437 IPMN patients, we identified 100 IPMN patients who developed pancreatic carcinomas during long-term surveillance. We examined serial changes of blood markers (carbohydrate antigen 19-9 [CA19-9], hemoglobin A1c [HbA1c], and pancreatic enzymes) and morphological features (worrisome features and high-risk stigmata) during the prediagnostic period of pancreatic carcinomas, overall and by carcinoma types (IPMN-derived vs. concomitant pancreatic carcinomas). RESULTS: CA19-9 elevation was observed in 39 patients and was associated with a metastatic stage. Compared to IPMN-derived carcinomas, concomitant carcinomas were more likely to represent CA19-9 elevation (60% vs. 30%, respectively; P = 0.005). HbA1c levels elevated only in 3 patients. Pancreatic enzyme elevation was observed in 18 patients with no differences in frequencies between the carcinoma types. All patients with elevated levels of blood markers had positive findings on cross-sectional imaging. High-risk stigmata or worrisome features were observed in all patients but one with concomitant carcinoma. The most common types of worrisome features were the main pancreatic duct dilatation and CA19-9 elevation in IPMN-derived and concomitant carcinomas, respectively. Compared to IPMN-derived carcinomas, concomitant carcinomas were less likely to harbor high-risk stigmata (16% vs. 86%, respectively; P < 0.001). CONCLUSIONS: The usefulness of currently available blood biomarkers was limited in early detection of pancreatic carcinomas related to IPMNs. Morphological alterations were well correlated with long-term risk of IPMN-derived carcinomas, but not with that of concomitant carcinomas.

[Sixteen Cases of Appendiceal Mucinous Neoplasm].

Appendiceal mucinous neoplasm is a relatively rare disease. It is classified as mucinous adenocarcinoma(MACA)and low- grade appendiceal mucinous neoplasm(LAMN). We retrospectively evaluated 16 cases of appendiceal mucinous neoplasm (LAMN: 13 cases, MACA: 3 cases)that were surgically resected in our hospital between January 2010 and July 2021. There were 7 men and 9 women, with a median age of 61 years(27-85 years). The most common chief complaint was abdominal pain(12 patients), while 3 cases were incidental findings following medical checkups for other diseases and without a chief complaint. Colonoscopy was performed for 9 cases. Of these, 5 revealed abnormal findings. The preoperative diagnosis was appendicitis in 7 patients and appendiceal tumor in 8 patients. The surgical procedures were planned for 8 cases and performed as emergencies in 8 cases. The procedures included laparoscopic surgery(n=6)and laparotomy(n=10). The resection range included appendectomy(n=9), partial cecal resection(n=4), and ileocecal resection(n=3). Surgical margins were negative in all cases. Metastases were not observed in patients who underwent lymph node dissections (2 patients with MACA and 1 patient with LAMN). The median follow-up was 17 months(1-43 months). Recurrence including peritoneal pseudomyxoma was not detected in any of the patients.

Refined criteria for p53 expression in ovarian mucinous tumours are highly concordant with TP53 mutation status, but p53 expression/TP53 status lack prognostic significance.

In gynecological neoplasms, immunohistochemical (IHC) expression of p53 is generally an accurate predictor of TP53 mutation status if correctly interpreted by the pathologist. However, the literature concerning cut-offs, frequency and prognostic significance of p53 staining in ovarian mucinous tumours is limited and heterogeneous. We performed an analysis of 123 primary ovarian mucinous tumours including mucinous borderline tumours (MBT), mucinous carcinomas (MC), and tumours with equivocal features between MBT and MC. We assessed p53 expression for the three recognised patterns of aberrant staining in ovarian carcinoma [overexpression ('all'), null and cytoplasmic] but using a recently suggested cut-off for aberrant overexpression in ovarian mucinous tumours (strong nuclear p53 staining in ≥12 consecutive tumour cells) and correlated the results with next generation sequencing (NGS) in all qualitatively sufficient cases (92/123). Aberrant p53 expression was present in 25/75 (33.3%) MBT, 23/33 (69.7%) MC (75% of MC with expansile invasion and 61.5% with infiltrative invasion), and 10/15 (66.7%) tumours equivocal between MBT and MC. Regarding the 92 tumours with paired IHC and mutation results, 86 showed concordant results and six cases were discordant. Three discordant MBT cases showed aberrant expression but were TP53 wild-type on sequencing. Three cases had normal p53 expression but contained a TP53 mutation. Overall, IHC predicted the TP53 mutation status with high sensitivity (94.1%) and specificity (92.7%). The accuracy of IHC was 93.5% with a positive predictive value of 94.1% and a negative predictive value of 92.7%. When comparing MC cases with wild-type TP53 versus those with TP53 mutation, there were no significant differences concerning disease-free survival, local recurrence-free survival, or metastases-free survival (p>0.05). In the MBT subgroup, there were no events for survival analyses. In conclusion, using an independent large sample set of ovarian mucinous tumours, the results of our study confirm that the suggested refined cut-off of strong nuclear p53 staining in ≥12 consecutive tumour cells reflect high accuracy, sensitivity and specificity for an underlying TP53 mutation but the TP53 mutation status has no prognostic significance in either MC or MBT.