[A Case of Adenocarcinoma, HPV-independent, Mesonephric Type with Significant Response to Neoadjuvant Chemotherapy].

Adenocarcinoma, HPV-independent, mesonephric type (hereafter referred to as "mesonephric carcinoma") arising from the cervix is rare, its treatment has not been established, and its sensitivity to chemotherapy has not been fully investigated. Here we report on a 30-year-old female patient who presented at our hospital with a chief complaint of abnormal genital bleeding. We suspected cervical cancer. Based on examination, biopsy, and imaging, she was diagnosed with stage IIA2 adenocarcinoma of the cervix and was scheduled for surgery. Because she had a SARS-COV-2 infection, she was given two courses of paclitaxel-carboplatin (TC) therapy, based on the then-current surgical risk assessment after SARS-COV-2 infection, with a waiting period of at least 8 weeks. The patient was deemed to have a partial response and was treated with paclitaxel and carboplatin, after which she was deemed to have a partial response and underwent total hysterectomy. A diagnosis of stage IIA2 mesonephric carcinoma, ypT1b2N0M0, was made after histopathologic examination of an excised specimen. The patient was treated with 4 additional courses of TC therapy after surgery, and has had no recurrence in 13 months. We report a first case of response to neoadjuvant chemotherapy with TC regimen in a patient with mesonephric carcinoma of the cervix.

Extrauterine Mesonephric-like Carcinoma: A Comprehensive Single Institution Study of 33 Cases.

Extrauterine mesonephric-like carcinoma (ExUMLC) shares histologic, immunohistochemical (IHC), and molecular (MOL) features with endometrial mesonephric-like carcinoma (EnMLC). Its rarity and histologic overlap with Mullerian carcinomas contribute to underrecognition of ExUMLC. Aggressive behavior of EnMLC is well-documented; behavior of ExUMLC is yet to be characterized. This study presents the clinicopathologic, IHC, and MOL features of 33 ExUMLC identified over a 20-year time period (2002-2022) and compares the behavior of this cohort to more common upper gynecologic Mullerian carcinomas (low-grade endometrioid, LGEC; clear cell, CCC; high-grade serous, HGSC) and EnMLC diagnosed over the same time period. ExUMLC patients ranged from 37 to 74 years old (median=59 y); 13 presented with advanced stage (FIGO III/IV) disease. Most ExUMLC had the characteristic mixture of architectural patterns and cytologic features, as previously described. Two ExUMLC had sarcomatous differentiation, 1 with heterologous rhabdomyosarcoma. Twenty-one ExUMLC (63%) had associated endometriosis, and 7 (21%) arose in a borderline tumor. In 14 (42%) cases, ExUMLC was part of a mixed carcinoma representing >50% of the tumor in 12. Twenty-six cases (79%) were incorrectly classified as follows: LGEC or HGEC (12); adenocarcinoma, not otherwise specified (3); HGSC (3); LGSC (2); mixed carcinoma (1); carcinosarcoma, Mullerian type (2); seromucinous carcinoma (1); transitional pattern of HGSC (1); and female adnexal tumor of probable Wolffian origin (1). Three patients had occult synchronous endometrial LGEC. IHC facilitated diagnosis in all cases with an expression of GATA-3 and/or TTF-1 in conjunction with decreased hormone receptor expression in most tumors. MOL testing (n=20) identified a variety of mutations, most frequently: KRAS (15); TP53 (4); SPOP (4); and PIK3CA (4). ExUMLC and CCC were more likely to be associated with endometriosis ( P <0.0001). ExUMLC and HGSC had more recurrences compared with CCC and LGEC ( P <0.0001). Histologic subtype was associated with longer disease-free survival for LGEC and CCC versus HGSC and ExUMLC ( P <0.001). ExUMLC trended towards a similar poor overall survival as HGSC compared with LGEC and CCC, and EnMLC trended to shorter survival compared with ExUMLC. Neither finding reached significance. No differences were seen between EnMLC and ExUMLC with respect to presenting stage or recurrence. Staging, histotype, and endometriosis were associated with disease-free survival, but on multivariate analysis, only stage remained as an independent predictor of outcome. The tendency of ExUMLC to present at an advanced stage and have distant recurrence points to more aggressive behavior compared with LGEC with which it is most frequently confused, underscoring the importance of an accurate diagnosis.

Mesonephric Adenocarcinoma and Mesonephric-like Adenocarcinoma of the Urinary Tract.

Given the association of mesonephric adenocarcinoma (MA) of the uterine cervix with florid mesonephric hyperplasia, one would expect MAs to rarely arise in other anatomical locations that harbor mesonephric remnants. In contrast, mesonephric-like adenocarcinoma (MLA) is thought to arise from Müllerian origin without an association with mesonephric remnants. The current case series characterizes 4 cases of MA arising in the urinary bladder (1 woman and 3 men), 1 case of MA in the perirenal region (woman), and 1 case of MLA in the ureter (woman). All cases displayed morphologic features similar to MA of the uterine cervix and MLA of the ovary and endometrium, characterized by predominant tubular and focal glandular/ductal architecture. Mesonephric remnants in the bladder wall were closely associated with adjacent MA in cases 1 and 4. MLA in case 6 was associated with mesonephric-like proliferations and endometriosis. All cases (6/6) were diffusely positive for Pax8, and all displayed a luminal pattern of CD10 staining, except case 4 for which CD10 immunostain was not available for review. Gata3 was either focally positive (cases 1, 2, and 6), negative (case 3), or diffusely positive (case 5). TTF-1 was diffusely expressed in cases 1 and 3 and negative in cases 2, 5, and 6. Although a KRAS G12C somatic mutation was detected in case 6, hotspot mutations in KRAS, NRAS, and PIK3CA were not present in other tested cases. Our study demonstrates that MAs and MLAs of the urinary tract share similar histopathogenesis, morphology, and immunophenotype to their counterparts in the female genital tract. We propose that, in the urinary tract, MA might be classified as a distinctive tumor that arises from mesonephric remnants or presumed Wolffian origin if they are not related to Müllerian-type precursors. The tumor displaying similar morphology and immunoprofile to MA but associated with Müllerian-type precursors should be classified as MLA.

A rare case of primary ovarian mesonephric adenocarcinoma and a review of the literature.

OBJECTIVE: Are reported in the cervix in the female genital tract, has been reported in very few studies in the literature. In this report, we aimed to present a case with mesonephric carcinoma, which was detected in the ovary and is very rarely seen. CASE REPORT: In a case since the frozen section results of the left adnexal mass were reported as malignant. CONCLUSION: Ovarian mesonephric carcinoma is very rare and exhibits very different morphological patterns. Therefore, immunohistochemical and morphological findings should be evaluated together. If the pathological picture does not fit the common carcinomas of ovarian origin and this entity must be brought to mind, because, if these tumors with different molecular developmental pathways are diagnosed correctly, treatment schemes will change and targeted therapies will be developed too. KEY WORDS: Mesonephric carcinoma, Mesonephric like carcinoma, Ovarian carcinoma.

Mesonephric adenocarcinoma in the uterine corpus: A case report and review of the literature.

Mesonephric adenocarcinoma (MNA) is a rare malignancy arising from the mesonephric remnant of the female reproductive tract, typically found in the cervix. MNA is uncommon in the uterine corpus, only 33 cases have been described in the literature. A 55-year-old postmenopausal woman presented with pink vaginal discharge and bilateral hip pain for 2 months, with the help of histopathologic observation and immunohistochemical staining, a diagnosis of "MNA" was made. The tumor invaded the whole layer of myometrium without endometrium involvement, mesonephric remnants and hyperplasia of the mesonephric duct were also found at the periphery of the neoplasm. After the operation, the patient was treated with 3 cycles of chemotherapy. The patient was followed for 6 months with disease. Further experience to diagnose and cure this rare tumor is warranted.

Mesonephric adenocarcinomas in female genital tract: A case series.

ABSTRACT: Mesonephric adenocarcinoma (MNAC) is a very rare tumor that originates from mesonephric duct remnants of the female genital tract. Only a few cases were reported in the literature, and most of them occurred in the cervix, extremely rare in the uterine body and ovary. MNAC was rarely reported to arise in the uterine corpus, but never was reported in the ovary. Mesonephric-like adenocarcinomas are recently suggested to describe these neoplasms arising from the uterine corpus and ovary. Due to the rareness of the disease, little is known regarding clinical characteristics, pathological diagnosis, prognosis, and optimal management strategy of MNAC in the female reproductive system. We report a series of MNACs arising from the vagina, cervix, uterine corpus, ovary, and fallopian tube, to summarize the clinical characteristics, pathological diagnosis, treatment, and prognosis.We retrospectively analyzed all MNACs in the female genital tract derived from our institute from January 2010 till January 2020. Patients' clinical details and follow-up were obtained from hospital records and scans were obtained from picture archiving and communication system.A total of 11 patients were included. The median age of onset of symptoms was 52 years. All patients underwent total hysterectomy and bilateral salpingo-oophorectomy, and lymph node dissections were performed in 7/11 (63.6%) patients. Two/eleven (18.2%) received neoadjuvant chemotherapy before surgery and 7/11 (63.6%) received adjuvant chemotherapy after primary surgery. Of the 11 patients, only 1 patient received adjuvant radiation therapy. One patient died at the end point of this study, 9 patients (81.8%) survived and 1 patient was lost to follow-up. The mean follow-up duration was 33.5 months.Although there is no consensus for the optimal treatment of this rare disease, radical surgery is considered to be the initial choice for localized lesion. Given the high malignancy, the majority of MNAC or mesonephric-like adenocarcinoma patients who underwent adjuvant chemotherapy received 4 to 8 cycles of carboplatin/paclitaxel as a first-line treatment after primary surgery with a median progression-free survival of 12 months. Treatment for recurrent disease in these patients included gemcitabine, carboplatin, and paclitaxel. Radiation was very limited in the treatment of the disease.

Cervical Mesonephric Adenocarcinoma: A Case Report of a Rare Gynecological Tumor from Embryological Remains of the Female Genital Tract.

INTRODUCTION: Malignant mesonephric tumors are uncommon in the female genital tract, and they are usually located where embryonic remnants of Wolffian ducts are detected, such as the uterine cervix. The information about these tumors, their treatment protocol, and prognosis are scarce. CASE REPORT: A 60-year-old woman with postmenopausal vaginal bleeding was initially diagnosed with endometrial carcinoma. After suspicion co-testing, the patient underwent a loop electrosurgical excision of the cervix and was eventually diagnosed with mesonephric adenocarcinoma. She was subjected to a radical hysterectomy, which revealed International Federation of Gynecology and Obstetrics (FIGO) IB1 stage, and adjuvant radiotherapy. The follow-up showed no evidence of recurrence after 60 months. CONCLUSION: We present the case of a woman with cervical mesonephric adenocarcinoma. When compared with the literature, this case had the longest clinical follow-up without evidence of recurrence, which reinforces the concept that these tumors are associated with a favorable prognosis if managed according to the guidelines defined for the treatment of patients with cervical adenocarcinomas. Though a rare entity, it should be kept in mind as a differential diagnosis for other cervical cancers.

Mesonephric and mesonephric-like carcinomas of the female genital tract: molecular characterization including cases with mixed histology and matched metastases.

Mesonephric carcinoma of the cervix is a rare tumor derived from Wolffian remnants. Mesonephric-like carcinomas of the ovary and endometrium, while morphologically similar, do not have obvious Wolffian derivation. Here, we sought to characterize the repertoire of genetic alterations in primary mesonephric and mesonephric-like carcinomas, in the distinct histologic components of mixed cases, as well as in matched primary tumors and metastases. DNA from microdissected tumor and normal tissue from mesonephric carcinomas (cervix, n = 8) and mesonephric-like carcinomas (ovarian n = 15, endometrial n = 13) were subjected to sequencing targeting 468 cancer-related genes. The histologically distinct components of four cases with mixed histology and four primary tumors and their matched metastases were microdissected and analyzed separately. Mesonephric-like carcinomas were underpinned by somatic KRAS mutations (25/28, 89%) akin to mesonephric carcinomas (8/8, 100%), but also harbored genetic alterations more frequently reported in Müllerian tumors. Mesonephric-like carcinomas that lacked KRAS mutations harbored NRAS (n = 2, ovary) or BRAF (n = 1, endometrium) hotspot mutations. PIK3CA mutations were identified in both mesonephric-like (8/28, 28%) and mesonephric carcinomas (2/8, 25%). Only mesonephric-like tumors harbored CTNNB1 hotspot (4/28, 14%) and PTEN (3/13, 23%) mutations. Copy number analysis revealed frequent gains of chromosomes 1q and 10 in both mesonephric (87% 1q; 50% chromosome 10) and mesonephric-like tumors (89% 1q; 43% chromosome 10). Chromosome 12 gains were more frequent in ovarian mesonephric-like carcinomas, and losses of chromosome 9 were more frequent in mesonephric than in mesonephric-like carcinomas (both p = 0.01, Fisher's exact test). The histologically distinct components of four mixed cases were molecularly related and shared similar patterns of genetic alterations. The progression from primary to metastatic lesions involved the acquisition of additional mutations, and/or shifts from subclonal to clonal mutations. Our findings suggest that mesonephric-like carcinomas are derived from a Müllerian substrate with differentiation along Wolffian/mesonephric lines.

Whole-proteome analysis of mesonephric-derived cancers describes new potential biomarkers.

Mesonephric carcinomas (MEs) and female adnexal tumors of probable Wolffian origin (FATWO) are derived from embryologic remnants of Wolffian/mesonephric ducts. Mesonephric-like carcinomas (MLCs) show identical morphology to ME of the cervix but occur in the uterus and ovary without convincing mesonephric remnants. ME, MLC, and FATWO are challenging to diagnose due to their morphologic similarities to Müllerian/paramesonephric tumors, contributing to a lack of evidence-based and tumor-specific treatments. We performed whole-proteomic analysis on 9 ME/MLC and 56 endometrial carcinomas (ECs) to identify potential diagnostic biomarkers. Although there were no convincing differences between ME and MLC, 543 proteins showed increased expression in ME/MLC relative to EC. From these proteins, euchromatic histone lysine methyltransferase 2 (EHMT2), glutathione S-transferase Mu 3 (GSTM3), eukaryotic translation elongation factor 1 alpha 2 (EEF1A2), and glycogen synthase kinase 3 beta were identified as putative biomarkers. Immunohistochemistry was performed on these candidates and GATA3 in 14 ME/MLC, 8 FATWO, 155 EC, and normal tissues. Of the candidates, only GATA3 and EHMT2 were highly expressed in mesonephric remnants and mesonephric-derived male tissues. GATA3 had the highest sensitivity and specificity for ME/MLC versus EC (93% and 99%) but was absent in FATWO. EHMT2 was 100% sensitive for ME/MLC & FATWO but was not specific (65%). Similarly, EEF1A2 was reasonably sensitive to ME/MLC (92%) and FATWO (88%) but was the least specific (38%). GSTM3 performed intermediately (sensitivity for ME/MLC and FATWO: 83% and 38%, respectively; specificity 67%). Although GATA3 remained the best diagnostic biomarker for ME/MLC, we have identified EHMT2, EEF1A2, and GSTM3 as proteins of interest in these cancers. FATWO's cell of origin is uncertain and remains an area for future research.

Atypical Mesonephric Hyperplasia of the Uterus Harbors Pathogenic Mutation of Kirsten Rat Sarcoma 2 Viral Oncogene Homolog (KRAS) and Gain of Chromosome 1q.

BACKGROUND/AIM: Mesonephric carcinoma (MNC) is a rare but notable entity of the female genital tract. While many researchers have acknowledged and studied MNC, much remains unknown on the characteristics of mesonephric remnant (MNR) or hyperplasia (MNH). There has not been any study examining the molecular features of MNR and MNH so far. The aim of this study was to investigate the clinicopathological and molecular characteristics of ten uterine mesonephric lesions, including two MNRs without atypia, four MNHs without atypia, and three MNHs with atypia. MATERIALS AND METHODS: We reviewed the electronic medical records and all available slides of ten cases from multiple institutions. Targeted sequencing and array comparative genomic hybridization were performed. RESULTS: Three atypical MNHs displayed nuclear enlargement, mild-to-moderate nuclear pleomorphism, and nuclear membrane irregularity, and harbored pathogenic Kirsten rat sarcoma 2 viral oncogene homolograt sarcoma 2 viral oncogene homolog (KRAS) mutation. Two of those that co-existed with MNC harbored the same sequence alterations as each of their adjacent MNC. One of the three atypical MNHs harbored chromosome 1q gain. CONCLUSION: Atypical MNH is a potential premalignant lesion in which KRAS mutation and chromosome 1q gain play an important role in the early stage of mesonephric carcinogenesis.

Ovarian mesonephric-like adenocarcinoma arising in serous borderline tumor: a case report with complex morphological and molecular analysis.

BACKGROUND: Mesonephric-like adenocarcinoma (M-LAC) is a rare, recently described tumor occurring in the uterine corpus and ovary, which shares the same morphological and immunohistochemical features with the more common mesonephric adenocarcinoma (MAC), which mostly arises the uterine cervix. Despite the similarities between these tumors, the histogenesis of M-LAC is still disputable. CASE PRESENTATION: Sixty-one-year-old woman presented with an advanced tumor of the left ovary with intraabdominal spread and liver metastases. After receiving 5 cycles of neoadjuvant chemotherapy, she underwent a hysterectomy with bilateral salpingo-oophorectomy, and resection of the liver metastasis, omentum, and appendix. Histologically, the ovarian tumor consisted of two components, whose morphology and immunohistochemical results were typical of either a serous borderline tumor (immunohistochemical positivity for PAX8, WT1, ER and PR) or a mesonephric-like carcinoma (immunohistochemical positivity for PAX8, TTF1 and GATA3). Only the component of the mesonephric-like adenocarcinoma metastasized to the omentum and liver. A molecular analysis with a panel of 271 genes (size 1020 kbp) was performed separately on samples from the borderline tumor, primary ovarian mesonephric-like adenocarcinoma, and liver metastasis. The results showed the clonal origin of all samples, which shared the same KRAS (NM_004985.3:c.34G > T, p.(G12C)) and PIK3CA (NM_006218.2:c.1633G > A, p.(E545K)) somatic mutations. Moreover, in the sample from the primary mesonephric-like carcinoma and its liver metastasis a likely pathogenic somatic MYCN mutation (NM_005378.4:c.131C > T, p.(P44L) was found. In all samples, the deletion of exons 9-10 in the CHEK2 gene was present, which is in concordance with the previously performed genetic testing of the blood specimen which revealed the hereditary CHEK2 mutation in this patient. CONCLUSIONS: Our result support the theory that at least some mesonephric-like ovarian adenocarcinomas are of Müllerian origin. The serous borderline tumor seems to be a precursor of mesonephric-like adenocarcinoma, which has been proven in our case by both tumors sharing the same mutations, and the presence of cumulative molecular aberrations in the mesonephric-like adenocarcinoma.

Cervical Mesonephric Adenocarcinoma With Novel FGFR2 Mutation.

Mesonephric adenocarcinoma is a rare tumor, accounting for <1% of cervical cancers. Well-differentiated mesonephric adenocarcinoma can be difficult to distinguish from diffuse mesonephric hyperplasia. Herein, we report a case of well-differentiated mesonephric adenocarcinoma with an FGFR2 mutation not previously reported in the literature. Nonselective tyrosine kinase inhibitors or FGFR2 inhibitors may represent options for targeted therapy.

Cytologic features of upper gynecologic tract adenocarcinomas exhibiting mesonephric-like differentiation.

BACKGROUND: Mesonephric adenocarcinomas are rare neoplasms which most commonly arise in the lateral cervix and vagina. Tumors with similar morphologic, immunophenotypic, and molecular characteristics recently have been described in the uterine corpus and ovary. Herein, the authors sought to characterize the cytomorphologic features of adenocarcinomas exhibiting mesonephric-like differentiation arising in the upper gynecologic tract. METHODS: Institutional databases were queried retrospectively for tumors of the upper gynecologic tract described as a "tumor of Wolffian origin" or "with mesonephric features" between 2007 and 2017. All available cytologic material was reviewed. Cytomorphologic characteristics were evaluated by 3 pathologists. RESULTS: The current study cohort consisted of 8 cases taken from 7 patients. Primary sites included the ovary (3 cases); endometrium (4 cases); and pelvis, not otherwise specified (1 case). All cases demonstrated tight 3-dimensional clusters of overlapping cells. Additional architectural features included tubular (5 of 8 cases; 63%) and papillary (3 of 8 cases; 38%) formations. Cells were small with scant (7 of 8 cases; 88%) to moderate (1 of 8 cases; 12%) cytoplasm. Three of the 8 cases (38%) demonstrated extracellular hyaline globules. Nuclei were uniform in size (6 of 8 cases; 75%) or showed mild anisonucleosis (2 of 8 cases; 25%). Nuclear grooves and indentations were observed in all cases. Mitoses (5 of 8 cases; 63%) and apoptotic bodies (4 of 8 cases; 50%), when present, were rare. No necrosis was noted. CONCLUSIONS: Adenocarcinomas exhibiting mesonephric-like differentiation show a monotonous population of small cells with scant to moderate cytoplasm and abundant nuclear grooves arranged in tight, overlapping, 3-dimensional clusters. Occasionally, papillary or tubular architecture, as well as extracellular hyaline globules, may be seen. These features should prompt further testing (eg, immunohistochemistry) to confirm the diagnosis and to exclude potential mimics.

Mesonephric adenocarcinoma of the cervix: a case report with a three-year follow-up, lung metastases, and next-generation sequencing analysis.

BACKGROUND: Mesonephric adenocarcinoma (MNAC) is a rare tumor of the female genital tract, which originates from mesonephric duct remnants. Its diagnosis is pathologically challenging, because MNAC may exhibit a mixture of morphological patterns that complicates the differential diagnosis. CASE PRESENTATION: The patient in this case was a 48-year-old woman with a polypoid mass protruding into the endocervical canal. The patient underwent a total hysterectomy outside the institution. During biopsy, the mass showed a cerebroid aspect. Histological study revealed a tumor with a predominantly tubular and ductal growth pattern. The immunoprofile showed negative staining for calretinin, carcinoembryonic antigen (CEAm), estrogen receptors (ER), and progesterone receptors (PR), and positive staining for CD10, p16, and PAX2. The Ki-67 score was 46%. Using a next-generation sequencing assay, we documented genomic alterations in KRAS and CTNNB1, low tumor mutation burden (TMB), and an absence of microsatellite instability. In addition, gain of the long arm of chromosome 1 (1q) was also documented using chomogenic in situ hybridization (CISH). Three years later, the patient presented pulmonary nodules in the lingula and left basal lobe that were resected by thoracotomy. The histopathologic study of the pulmonary nodules confirmed the presence of metastases. CONCLUSION: Carcinomas of mesonephric origin are among the rarest subtypes of cervical tumors. We report the first case of mesonephric adenocarcinoma of the cervix with lung metastases showing a CTNNB1 gene mutation.

Carcinosarcoma of the uterine cervix: a rare pathological finding originating from mesonephric remnants.

Carcinosarcoma of the uterine cervix is a very rare tumour that has been described in less than 70 cases in the literature. It is less common compared with carcinosarcoma of the uterine corpus and it can have two origins: the Müllerian ducts and the mesonephric duct remnants. The association of mesonephric carcinoma with a sarcomatous component was reported in only 11 cases, including the following. We describe a case of a 64-year-old woman, presenting with vaginal bleeding and a cervical lesion reported as a sarcoma of endometrial stroma in the first biopsy. After exclusion of distant disease, she was submitted to radical surgery and the final histopathological examination showed a carcinosarcoma of the cervix with mesonephric origin.

Clinicopathologic and Molecular Characteristics of Mesonephric Adenocarcinoma Arising From the Uterine Body.

Mesonephric adenocarcinoma (MNAC) is a rare tumor of the female genital tract mainly occurring in the uterine cervix. To date, only a few cases of MNAC arising from of the uterine body (UB-MNAC) have been reported. The clinicopathologic and molecular characteristics of UB-MNAC remain unknown. In this study, we investigated the clinical, histopathologic, immunohistochemical, and genetic features of UB-MNAC. In total, 11 cases were included. Six patients developed metastatic disease, most commonly in lungs (5/6). Histopathologically, UB-MNAC was characterized by an admixture of tubular, glandular, papillary, retiform, glomeruloid, sex cord-like, and comedonecrosis-like architectural patterns. Three adverse pathologic characteristics, including advanced International Federation of Gynecology and Obstetrics stage, high mitotic activity, and presence of lymphovascular the invasion, were independent factors predicting the development of metastasis. All cases were positive for GATA-binding protein 3 and paired box 2 expression and showed wild-type p53, patchy p16, and preserved PTEN expression, as indicated by immunohistochemistry. Next-generation sequencing using 12 samples (11 primary tumors and 1 metastatic tumor) revealed 42 single nucleotide variations in 16 genes, mostly in KRAS (10/12) and ARID1A (9/12). Copy number variation was found in 16 genomic regions, and consisted of 57 gains and 10 losses, with 1q gain (11/12) being the most prevalent. In conclusion, UB-MNAC displays an aggressive biological behavior, with a tendency to metastasize to the lungs. Adverse pathologic characteristics reflect the aggressive nature of UB-MNAC. Distinct molecular features of UB-MNAC include frequent somatic mutations of KRAS and ARID1A and gain of 1q.

An Ovarian Adenocarcinoma With Combined Low-grade Serous and Mesonephric Morphologies Suggests a Müllerian Origin for Some Mesonephric Carcinomas.

Mesonephric carcinomas are rare adenocarcinomas of the female genital tract that occur most commonly in the uterine cervix. They are classically thought to arise from benign mesonephric remnants, and are rarely reported at other sites in the gynecologic tract. Here we present an interesting biphenotypic ovarian adenocarcinoma with intimately associated but distinct components of both low-grade serous carcinoma and mesonephric-like carcinoma. A serous borderline tumor was present adjacent to the invasive carcinoma, and no benign mesonephric precursors were identified. Numerous invasive peritoneal metastases were present, including multiple metastases with both low-grade serous and mesonephric-like elements. Consistent with recent reports, foci of mesonephric-like carcinoma were morphologically and immunohistochemically identical to classic mesonephric carcinoma of the cervix. On molecular analysis, the serous borderline tumor, primary and metastatic low-grade serous carcinoma, and primary and metastatic mesonephric-like carcinoma each harbored a shared NRAS p.Q61R hotspot mutation, shared gains in chromosome 1q and 18p, and shared losses in chromosomes 1p, 18q, and 22. These shared molecular features indicate a clonal relationship between all morphologic elements of this ovarian adenocarcinoma, suggesting that at least some mesonephric carcinomas may arise from Müllerian precursors.

Mesonephric adenocarcinoma of the uterine corpus with intracystic growth completely confined to the myometrium: a case report and literature review.

BACKGROUND: Mesonephric adenocarcinoma (MA) is a rare tumor believed to arise from mesonephric remnants occurring mostly in the uterine cervix and, to a lesser extent, the corpus. Since the first case report of MA in the corpus in 1995, only 16 cases have been reported in the English literature. A recent report suggested that MA originates in Müllerian tissue and exhibits the mesonephric differentiation phenotype. CASE PRESENTATION: An asymptomatic 61-year-old woman was referred to our hospital because of elevated levels of tumor markers. Imaging revealed an intramural lesion of the uterine corpus exhibiting fluorodeoxyglucose uptake. A total hysterectomy and bilateral salpingo-oophorectomy were performed. The tumor was completely confined to the corpus wall and was composed of an intracystic bulky component and an invasive component in the myometrial layer. The tumor exhibited a variety of growth patterns, including a characteristic tubular pattern with dense eosinophilic secretion reminiscent of the thyroid, as well as a variety of morphologies, such as acinar, papillary, and ductal structures. The structures were immunoreactive for CK7, vimentin, CD10, calretinin, PAX8, and GATA3 and almost completely negative for ER/PgR. CA125 and CA19-9 antigen expression was also detected. CONCLUSION: A case of MA with a unique growth pattern of an intracystic mass within the corpus wall is presented. The histogenesis and differential diagnoses are discussed. The histogenesis of MA is not yet clear. We hypothesize two different pathways involved: 1) direct development from the mesonephric remnants and/or 2) mesonephric transformation of Müllerian adenocarcinoma.