Adenomatoid tumors of the female and male genital tracts: a clinicopathological and immunohistochemical study of 44 cases

Adenomatoid Tumor Mimicking Peritoneal Carcinomatosis: A Case Report

An adenomatoid tumor (AT) is a benign lesion, which is commonly located in the genital tract of both sexes. We present a case of a 66-yr-old woman with the unusual characteristics of an AT mimicking peritoneal carcinomatosis. The tumor was detected incidentally by ultrasound examination, and an ensuing imaging study raised suspicion of ovarian cancer with peritoneal carcinomatosis. From the pathologic diagnosis of frozen specimens, clear cell carcinoma was noted and the patient subsequently underwent cytoreductive surgery. An 8.5-cm-sized mass was observed on the uterine serosa, extending into the myometrium. In addition, multi-cystic nodular lesions were identified in the omentum, appendiceal and small bowel serosa, and the peritoneum. After histologic and extensive immunohistochemical examinations, the final diagnosis was AT. Recognition of the diverse presentations of AT is crucial for accurate diagnosis and appropriate treatment, as these tumors can involve multiple sites and mimic peritoneal carcinomatosis, potentially leading to a misdiagnosis of malignancy.

Case report: Imaging of adrenal adenomatoid tumors: reports of two cases and review of literature

Adenomatoid tumors (ATs) are uncommon, benign tumors of mesothelial origin, most frequently found in the genital tracts of both sexes. Extragenital localization sites, such as adrenal glands, are extremely rare. Since patients with adrenal ATs have no obvious clinical symptoms, imaging examination has become important evidence for diagnosis. Although previous literature noted that the imaging findings of adrenal ATs were nonspecific, no relevant studies have confirmed this. We herein present two novel cases of adrenal ATs, confirmed by immunohistochemistry, and that were initially misdiagnosed as other, more common adrenal tumors based on clinical findings and preoperative imaging. Including our cases, we collected a total of 33 previously reported adrenal ATs and extracted all available imaging information from them, aiming to find some radiological characteristics of this rare tumor. Through the review, we identified some nonspecific imaging features of adrenal ATs; however, the final diagnosis still depends on pathology and immunohistochemistry results.

Adenomatoid tumor of the fallopian tube: A case report and a review of the literature

INTRODUCTION

Adenomatoid tumor is a rare, benign condition, more common in males, that affects the epididymis, spermatic cord and testicular tunics, whereas in females, the uterus and fallopian tubes. This solitary tumor is commonly appearing as an incidental finding. The diverse morphological characteristics of these tumors pose challenges in differential diagnoses.

PRESENTATION OF CASE

We report a case of a 33-year-old woman with a multilocular solid mass identified in a routine gynecological check-up. The cyst was removed laparoscopically, and histology analysis reported an adenomatoid tumor of the fallopian tube. Patient recovered without any additional treatment and within 2 years delivered a healthy offspring. Extensive literature search was conducted in Pubmed, Embase and Google Scholar for the identification of all relevant case reports or case series of adenomatoid tumors of the fallopian tubes.

DISCUSSION

Literature search revealed other 49 cases of adenomatoid tumors in fallopian tube published. The mean age of patients was 45,6 years (ranged from 29 to 72 years) and the mean diameter of the tumor was 10 mm.

CONCLUSION

Laparoscopic removal of such a rare, benign tumor is effective and safe.

MR Imaging Findings of Uterine Adenomatoid Tumors

PURPOSE

Adenomatoid tumor is a rare benign genital tract neoplasm of mesothelial origin. Uterine adenomatoid tumors occur in the outer myometrium and may mimic leiomyomas. Because hormonal treatment is not applicable to adenomatoid tumors and laparoscopic enucleation is not easy as myomectomy, it is important to differentiate adenomatoid tumors from leiomyomas for the adequate treatment. The purpose of this study is to evaluate the MRI findings of adenomatoid tumor for the differentiation from leiomyoma.

METHODS

MRI findings of surgically proven 10 uterine adenomatoid tumors in 9 women were retrospectively evaluated with correlation to histopathological findings.

RESULTS

All 10 tumors appeared as solid myometrial masses and showed heterogeneous signal intensity with admixture of partially ill-defined slight high-intensity areas containing abundant tubular tumor cells and well-defined myoma-like low-intensity areas reflecting smooth muscle hypertrophy on T2WI including 4 lesions with peripheral ring-like high intensity. High-intensity areas on T2WI tended to show high intensity on diffusion-weighted imaging (DWI) with relatively high apparent diffusion coefficient (ADC), suggesting T2 shine-through effect due to abundant tubules. Intra-tumoral hemorrhage revealed on MRI was rare. Early intense contrast-enhanced areas on dynamic contrast-enhanced study were observed dominantly within the high-intensity areas but rarely within the low-intensity areas on T2WI.

CONCLUSION

The outer myometrial mass with the admixture of well-defined low- and ill-defined high-intensity areas on T2WI may be suggestive of adenomatoid tumor. Peripheral ring-like high intensity on T2WI and DWI may also be suggestive. Dynamic contrast-enhanced MR study may be helpful for the differentiation from leiomyoma.

The Incidental Diagnosis of Adenomatoid Tumour on Fallopian Tubes Submitted for Tubal Ligation at a Tertiary Laboratory in Northern Pretoria, South Africa

Introduction

Adenomatoid tumours are the most common benign mesothelial neoplasms of the fallopian tube. They are usually diagnosed incidentally in specimens submitted for bilateral tubal ligation and can be mistake for vascular or epithelial lesions.

Materials and methods

A retrospective analysis of cases with adenomatoid tumour of the fallopian submitted for tubal ligation from 2012 to 2020. The clinicopathological characteristic data was retrieved from the laboratory information system.

Results

A total of 11 cases with adenomatoid tumour of the fallopian tubes submitted for tubal ligation were identified in women with average age of 30.9 years. In all the cases, only 1 fallopian tube was affected. Grossly, the fallopian tubes did not show any discernible tumour. Immunohistochemical stains confirmed the diagnosis of adenomatoid tumours in all the cases.

Conclusion

Adenomatoid tumours in fallopian tubes are infrequent, and pathologists shouldn't overlook them especially in unsuspicious instances. As frequent as adenomatoid tumour of the fallopian tubes are uncommon, pathologists show be aware of as their misdiagnosis could lead mismanagement of patient with far reaching complication.

Epididymal Adenomatoid Tumour: A Case Report

Adenomatoid tumours are rare benign neoplasm involving the para testicular region, mostly the tail of the epididymis. They are typically small, firm and asymptomatic masses in the scrotal region and often discovered incidentally during physical examination or imaging studies. It is very challenging to differentiate them clinically and radiologically from malignant intratesticular solid tumours, which may lead to unnecessary orchidectomies. This case report presents the clinical management of a 57-year-old male patient with adenomatoid tumour of the epididymis, highlighting the diagnostic workup, surgical approach and postoperative outcomes. In addition, a comprehensive literature review was conducted to discuss the morphological and immunohistochemical features to improve understanding of these rare lesions and assist in accurate diagnosis and appropriate management.

Adenomatoid tumors of ovary mimicking malignancy: report of 2 cases and literature review

BACKGROUND

Adenomatoid tumors (ATs) are benign tumors originating from the mesothelium. ATs of the ovary are rare, and can easily be confused with malignancy due to the histomorphological diversity. Thus, it is difficult in histopathological and differential diagnosis, especially during intraoperative frozen pathological diagnosis, which directly affects the resection scope of surgery.

CASE PRESENTATION

In this study, we reported two patients (58 and 41 year old) with ovarian ATs. AT of patient 1 occurred in both ovaries at different time points and she had been diagnosed with Hashimoto's thyroiditis. AT of patient 2 occurred in right ovary. Intraoperative frozen pathological diagnosis was performed in both cases and laparoscopic salpingo-oophorectomy was undergone on the lesion side according to benign freezing diagnostic result. Ovarian ATs, the final diagnoses of the 2 cases were concluded after histological, extensive immunohistochemical (IHC), histochemical, and fluorescence in situ hybridization analyses.

CONCLUSIONS

Our results show that ovarian ATs may not be related to BAP1 or CDKN2A/p16 mutations. In addition, the case 1 suggests that ATs may be associated with immune dysregulation. When encountering such similar lessions, we recommend that a series of immunohistochemical, histochemical and molecular biological techniques should be used for diagnosis and differential diagnosis to avoid misdiagnosis. Improving understanding of the rare ovarian ATs which mimic malignancy is necessary to prevent overresection.

Diffuse WT1 Positivity in Smooth Muscle Component Supports Dual Differentiation of Mesothelial Cells in the Histogenesis of Leiomyoadenomatoid Tumors—A Report of two Cases

Leiomyoadenomatoid tumors of the epididymis are exceedingly rare biphasic tumors composed of an adenomatoid component in the form of gland-like structures lined by single flat or cuboidal cells admixed with smooth muscle. Radiological and gross findings cannot distinguish leiomyoadenomatoid tumors from the more common classic adenomatoid tumors or leiomyomas, and careful microscopic examination is critical in the identification of this esoteric variant. The histogenesis of this entity remains ambiguous. Common hypotheses include a collision tumor, a variant of an adenomatoid tumor with a smooth muscle component, or an adenomatoid tumor arising in the background of reactive smooth muscle hyperplasia. We present 2 cases of leiomyoadenomatoid tumors with diffuse nuclear WT1 positivity in both the adenomatoid and smooth muscle components, supporting the mesothelial origin of these tumors.

Epididymal adenomatoid tumor: a case report and literature review

Background

Adenomatoid tumor is a very rare benign neoplasm of mesothelial origin affecting mainly female and male genital tracts. The diagnosis is challenging as this tumor mimics many differential diagnoses. The current literature offers only some case reports and short series of adenomatoid tumors.

Case presentation

A 47-year-old patient with unremarkable medical history presented for chronic mild pain of the right testis evolving for months. The physical examination shows a palpable right intrascrotal nodule of 10 mm in greatest diameter. The nodule was painful, mobile with firm consistency. The laboratory investigations were within normal limits, the scrotal ultrasonography showed a well-circumscribed predominantly hyperechoic intrascrotal nodule in the right epididymal head with heterogeneous echostructure. Excisional biopsy of the lesion was performed and the histopathological analysis showed a well-circumscribed tumor with microcystic and trabecular architecture made of small interconnected tubules and cysts lined by flattened cells with prominent vacuolization and thread-like bridging strands, consistent with an epididymal adenomatoid tumor. The postoperative course was uneventful and the patient was discharged. Four months after surgical treatment, the patient has no sign of the disease.

Conclusion

Testicular adenomatoid tumors are uncommon benign neoplasms with diagnostic challenge. Adenomatoid tumors arising in epididymis are managed by excisional biopsy with testis-sparing surgery avoiding unnecessary orchidectomy.

Adenomatoid tumours of the gastrointestinal tract - a case-series and review of the literature

AIMS

Adenomatoid tumours are mesothelial-derived benign neoplasms with a predilection for the genital tract. Extragenital sites are rare and can cause significant diagnostic challenges. Herein, we describe the clinicopathological features of a cohort of adenomatoid tumours involving the gastrointestinal tract and liver in order to more clearly characterise their histological findings and aid in diagnosis.

METHODS AND RESULTS

The pathology databases at four institutions were searched for adenomatoid tumours involving the gastrointestinal tract or liver, yielding eight cases. Available clinicoradiological and follow-up data were collected from the medical records. Six tumours were incidentally discovered during imaging studies or at the time of surgical exploration for unrelated conditions; presenting symptoms were unknown in two patients. Histologically, the tumours were well-circumscribed, although focal ill-defined borders were present in four cases. No infiltration of adjacent structures was identified. Architectural heterogeneity was noted in five (63%) tumours; an adenoid pattern often predominated. The neoplastic cells were flattened to cuboidal with eosinophilic cytoplasm. Cytoplasmic vacuoles mimicking signet ring-like cells were present in five (63%) cases. Three (38%) cases showed involvement of the mesothelium with reactive mesothelial hyperplasia. Cytological atypia or increased mitotic activity was not identified. The surrounding stroma ranged from oedematous/myxoid to densely hyalinised. Immunohistochemistry confirmed mesothelial origin in all cases evaluated. No patients developed recurrence of disease.

CONCLUSIONS

The current study evaluates the clinicopathological findings in a collective series of gastrointestinal and hepatic adenomatoid tumours, correlating with those described in individually reported cases. We highlight common histological features and emphasise variable findings that could mimic a malignant neoplasm.

Leiomyoadenomatoid tumours of the epididymis: A new case report and review of the literature

Benign tumours of the epididymis are rare, and the most common tumour types include adenomatoid tumours, representing more than half of all cases, and leiomyomas. Here, we reported a case of leiomyoadenomatoid tumours of the epididymis, a very rare, benign histological entity with only few cases described in the English literature, which have been reviewed and summarised. Clinically, the lesion presented as a solitary mass growing at the level of the tail of the right epididymis. After the intraoperative frozen section analysis revealed a benign adenomatoid lesion, the mass was enucleated with a conservative surgery sparing the testis. This case highlights the importance for both pathologists and urologists to be aware of these rare, but benign, tumours, to avoid misdiagnosis, especially in the setting of frozen intraoperative consultation, or primary radical surgical procedures, as radical orchiepididymectomy without frozen section consultation.

Adenomatoid Tumor of Fallopian Tube With "Deciduoid" Morphology and Atypical Nuclear Features

Adenomatoid tumor is a benign neoplasm of mesothelial origin. Adenomatoid tumor in female genital tract shows typical morphologic features with bland nuclei. Deciduoid morphology has not been reported in adenomatoid tumor. Tumors with deciduoid cells and atypical nuclear features may pose a diagnostic challenge and raise the suspicion of malignancy. We present a case of fallopian tube adenomatoid tumor with deciduoid morphology and atypical nuclear features in a 39-year-old woman with prolonged progestin therapy. We hypothesize that the unusual morphological changes in adenomatoid tumor, like deciduoid morphology and nuclear atypia, may be secondary to hormone effects.

Adenomatoid Tumor of the Uterus: A Report of 6 Unusual Cases With Prominent Cysts Including 4 With Diffuse Myometrial Involvement, 4 With Uterine Serosal Involvement, and 2 Presenting in Curettage Specimens

We evaluated the clinicopathologic features of 6 adenomatoid tumors of the uterus with unusual features. All the tumors differed grossly from the usual adenomatoid tumor, typically being ill-defined and occupying >50% of the myometrium, essentially replacing it in 4. The neoplasm extended to the endometrium in 2 cases and in one of these it formed an intracavitary mass; in both the tumor was first diagnosed in a curettage. In the other 4 cases, the adenomatoid tumor was discovered in a hysterectomy specimen performed for irregular vaginal bleeding (3 patients), and the finding of a pelvic mass on a computed tomography scan in a patient with right lower quadrant pain. The tumors extended to the uterine serosa in the form of small grape-like vesicles or cysts in 4 cases. All tumors contained the typical small often irregularly shaped spaces but also had prominent cysts. When cysts involved the serosa, the microscopic appearance mimicked that of peritoneal inclusion cysts. In one case with serosal involvement, a prominent papillary pattern was also present. The cysts were typically closely packed with minimal intervening stroma but were occasionally separated by conspicuous smooth muscle bundles. The stroma in one case was extensively hyalinized. Two tumors were focally infarcted. A striking, but minor, solid growth in which the tumor cells were arranged in tightly packed nests or interanastomosing cords and trabeculae was seen in 2 tumors. The unusual gross and microscopic features of these tumors can cause significant diagnostic difficulty and bring into the differential diagnosis entities that are usually not realistic considerations. The presentation of 2 tumors in a curettage specimen represents an unusual clinical aspect.

TRAF7 mutations and immunohistochemical study of uterine adenomatoid tumor compared with malignant mesothelioma

Adenomatoid tumors (ATs) are benign mesothelial tumors with a good prognosis and usually occur in female and male genital tracts, including in the uterus. ATs are genetically defined by tumor necrosis factor receptor-associated factor (TRAF) 7 mutations, and a high number of AT cases show immunosuppression. On the other hand, malignant mesotheliomas (MMs) are malignant mesothelial tumors with a very poor prognosis. Genetic alterations in TRAF, methylthioadenosine phosphorylase(MTAP), and BRCA-associated nuclear protein 1 (BAP1) in ATs derived from the uterus and MMs of pleural or peritoneal origin were compared by gene sequence analysis or immunohistochemical approaches. Formalin-fixed paraffin-embedded tissues derived from patients were used for immunohistochemical staining of L1 cell adhesion molecule (L1CAM), BAP1, MTAP, and sialylated protein HEG homolog 1 (HEG1) in 51 uterine AT cases and 34 pleural or peritoneal MM cases and for next-generation sequencing of the TRAF7 gene in 44 AT cases and 21 MM cases. ATs had a significantly higher rate of L1CAM expression than MMs, whereas MMs had a significantly higher rate of loss of MTAP and BAP1 expression than ATs. There was no difference in the rate of HEG1 expression between the tumor types. Most of the ATs (37/44; 84%) had somatic mutations in TRAF7, but none of the MMs had somatic mutations in TRAF7 (0/21; 0%). In addition, a low number of AT cases were associated with a history of immunosuppression (9/51; 17.6%). TRAF7 mutation is one of the major factors distinguishing the development of AT from MM, and immunosuppression might not be associated with most AT cases.

Adenomatoid Tumor of the Adrenal Gland: Report of Two Cases and Review of the Literature

Adenomatoid tumor (AT) is an uncommon benign neoplasm of mesothelial origin, usually occurring in the female and male genital tracts. Extragenital localization such as the adrenal gland is extremely rare. Until now, only 39 cases of adrenal AT have been reported in the English literature. Here we report two novel cases of adrenal AT that occurred in male patients aged 30 and 31 years. The tumors were discovered incidentally by computed tomography (CT). Macroscopically, the tumors were unilateral and solid, and the greatest dimension of the tumors was 3.5 and 8.0 cm, respectively. Histologically, the tumors consisted of angiomatoid, cystic, and solid patterns and infiltrated the adrenal cortical or medullary tissue. The tumor cells had low nuclear/cytoplasmic ratio, with no pathological mitosis or nuclear pleomorphism. Thread-like bridging strands and signet-ring-like cells could be seen. Immunohistochemically, the tumor cells were positive for epithelial markers (AE1/AE3, CK7) and mesothelial markers (D2-40, calretinin, and WT-1). The Ki-67 index was approximately 1 and 2%, respectively. The differential diagnosis of adrenal AT includes a variety of benign and malignant tumors. The patients had neither local recurrence nor distant metastasis at 21 and 8 months after removal of the tumor. In the literature review, we comprehensively summarized the clinical, morphological, immunohistochemical, and prognostic features of adrenal AT. Adrenal ATs are morphologically and immunophenotypically identical to those that occur in the genital tracts. Combining the histology with immunohistochemical profiles is very supportive in reaching the diagnosis of this benign tumor, helping to avoid misdiagnosis and overtreatment.

Paratesticular tumors. A clinicopathological study from a single tertiary hospital in North India

OBJECTIVE

Paratesticular tumors (PTT) are rare and form a heterogenous group, ranging from benign to malignant high grade sarcomas. This study was undertaken to describe the clinicopathological spectrum of PTTs received over a 20-year period.

METHODS

All primary and secondary PTTs diagnosed from 2000 to 2019 in the pathology department of a tertiary care hospital in North India were retrospectively reviewed. Gross, histopathological features and immunohistochemistry (IHC) findings were correlated with clinical details.

RESULTS

A total of 169 intra-scrotal tumors were diagnosed during the study period, out of which there were 30 PTTs (in 27 patients) comprising 17.75%. Age range was 4 to 85 years (median 58 years). Benign PTTs were the commonest (n = 21, 70%), followed by metastasis to the paratesticular region (n = 6, 20%) and then primary malignant PTTs (n = 3, 10%). The commonest benign PTT was lipoma (n = 16, 76.19%), followed by adenomatoid tumor (n = 3, 14.28%) with one case each (4.76%) of cellular angiofibroma and hemangioma. Among primary malignant PTT, there were two cases of rhabdomyosarcoma, and one case of biphasic malignant mesothelioma. Metastatic tumors included four cases of prostatic adenocarcinoma, and one case each of pancreatic signet ring cell carcinoma and clear cell renal cell carcinoma.

CONCLUSION

PTTs show a wide clinicopathological spectrum. Benign PTTs are commoner than malignant PTTs. Meticulous grossing and histopathological examination supplemented by IHC is essential for an accurate diagnosis of this heterogenous class of tumors, which influences the role of adjuvant therapy and patient prognosis.

Adenomatoid Tumor: A Review of Pathology With Focus on Unusual Presentations and Sites, Histogenesis, Differential Diagnosis, and Molecular and Clinical Aspects With a Historic Overview of Its Description

Adenomatoid tumors have been described almost a century ago, and their nature has been the subject of debate for decades. They are tumors of mesothelial origin usually involving the uterus, the Fallopian tubes, and the paratesticular region. Adenomatoid tumors of the adrenal gland, the liver, the extragenital peritoneum, the pleura, and the mediastinum have been rarely reported. They are usually small incidental findings, but large, multicystic and papillary tumors, as well as multiple tumors have been described. Their pathogenesis is related to immunosuppression and to TRAF7 mutations. Despite being benign tumors, there are several macroscopic or clinical aspects that could raise diagnostic difficulties. The aim of this review was to describe the microscopic and macroscopic aspects of adenomatoid tumor with a special focus on its differential diagnosis and pathogenesis and the possible link of adenomatoid tumor with other mesothelial lesions, such as the well-differentiated papillary mesothelioma and the benign multicystic mesothelioma, also known as multilocular peritoneal cysts.

Uterine adenomatoid tumor associated with lymph node lesions: a case report

We report a case of uterine adenomatoid tumor (AT) with regional lymph node involvement in a 49-year-old woman. Magnetic resonance imaging revealed an aggregated cystic mass in the posterior uterine wall with partial protrusion of the tumor outside the uterus, and cystic masses of same characteristics in the bilateral obturator and right common iliac lymph nodes. FDG PET/CT revealed no significant FDG uptake in the uterine and lymph node lesions. Taking possible lymph node metastasis into consideration, hysterectomy and lymph node biopsy were performed and it revealed AT of the uterus and the lymph nodes histopathologically.

Appendageal tumors and tumor-like lesions of the testis and paratestis: a 32-year experience at a single institution

The testicular hilum and paratestis contain several embryologically diverse anatomic structures, including the spermatic cord, tunica vaginalis, epididymis, rete testis, and several other embryonic remnants. Several benign and malignant lesions arise from these morphologically distinct structures, and owing to their proximity, it is challenging to classify and subsequently stage these tumors. Herein, we conducted a retrospective review of the paratesticular appendageal and rete testis tumors and tumor-like lesions diagnosed at our department from 1985 to 2016. Soft-tissue lesions/tumors were excluded. A total of 146 paratesticular appendageal and rete testis tumors and tumor-like lesions were identified. Most were benign (n = 107; 73%). Adenomatoid tumor (26%) was the most common benign tumor, followed by different types of cysts (19%), mesothelial hyperplasia (18%), serous cystadenoma (5.5%), and rete testis adenoma (4%). Malignant lesions comprised 23% of the cases, with mesothelioma the most common (15%), followed by adenocarcinoma of the rete testis (4%), serous cystadenocarcinoma (2%), and papillary and clear cell adenocarcinoma of the epididymis (2%). Finally, serous borderline tumors and melanotic neuroectodermal tumor (retinal anlage tumors) comprised the remaining 4% of cases. In conclusion, a wide range of benign and malignant lesions can arise from the paratesticular region. Awareness of these lesions and their histologic spectrum is crucial to avoid diagnostic pitfalls and to allow pathologists to establish a correct diagnosis and subsequent treatment plan.

Non-random adenomatoid tumours of the female genital system: A comparative clinicopathologic analysis of 14 cases

The aim of this study was to evaluate adenomatoid tumours (AT) clinicopathologically in the female genital tract and compare the histomorphological features of ATs according to their uterine or tuba-ovarian location. Cases of AT were excised and collected from female genital tracts between the years of 2010-2017. Cases were evaluated depending on their clinical findings, localisation and pathological properties. There were 14 cases of AT. Ten cases were uterine, and 4 cases were adnexal tumours. The diagnostic ratio of uterine ATs was 64.3%, and of tuba-ovarian ATs was 21.4% (P > 0.05). The size of the largest tumour was 6 cm. Two of the uterine and one of the ovarian cases had a macrocyst; 2 uterine and one ovarian case had a microcyst; and 6 uterine had a combined microcystic/trabecular pattern. Uterine cases showed a higher number of smooth muscle component, signet-ring cells and infiltrative nature compared with other cases (P < 0.05). All uterine cases were infiltrative. Most of ATs of the female genital system were small in size and incidentally diagnosed in our cases but rarely detected as an adnexal mass forming lesion which mimics a malignancy. A comparative clinicopathologic analysis of these cases should be considered with the histomorphological and immunohistochemical features for an accurate differential diagnosis.

Fallopian Tube Neoplasia and Mimics

This review discusses select fallopian tube entities and their associated mimics. It first focuses on adenomatoid tumors, the most common benign tumor of the fallopian tube. High-grade serous carcinoma and its precursor, serous tubal intraepithelial carcinoma, are then addressed. Finally, attention is turned to endometrioid proliferations of the fallopian tube. A diagnostic approach is provided for these lesions, with an emphasis on differential diagnoses and situations in which a benign lesion may appear malignant, and vice-versa.

An Unusual Adenomatoid Tumor of Fimbria with Pronounced Psammoma Bodies in a BRCA Positive Patient as a Pitfall for Carcinoma on Frozen Section

Background

BRCA gene mutations significantly increase the risk of breast and ovarian cancers where the lifetime risk of the ovarian cancer is about 40%. Therefore, many women with such mutations undergo prophylactic bilateral mastectomy and salpingo-oophorectomy. About 5-6% of these individuals display occult carcinomas in tubo-ovarian locations of which over 85% are tubal in origin. The objective of this case study was to emphasize emergence of benign lesions mimicking cancer under these circumstances.

Case Report

We present a case with positive BRCA1 mutation who underwent the prophylactic procedure where a small mass was identified in her fallopian tube. Our initial encounter with this tumor was during intraoperative consultation. The tumor was associated with extensive psammoma bodies arranged in closely packed small tubules, mimicking serous carcinoma. Frozen section limitations including artifact, time constraint, and lack of ancillary studies as well as the clinical history further complicated our diagnostic assessment, which was deferred. A diagnosis of adenomatoid tumor was rendered on permanent sections.

Conclusion

It is important to be familiar with this morphologic presentation of adenomatoid tumor as it is a pitfall for carcinoma, particularly on frozen section, and inaccurate diagnosis could lead to further unnecessary extensive procedures.

A Contemporary Review of Common Adult Non-germ Cell Tumors of the Testis and Paratestis

This article provides a comprehensive review of non-germ cell tumors of the testis and paratestis in adults, incorporating the latest 2016 World Health Organization updates. Clinical features, gross pathologic findings, key morphologic details, immunohistochemical profiles, and differential diagnoses are covered, with an emphasis on how to resolve commonly encountered, and sometimes difficult, differential diagnoses.

[Ectopic tissue of the female genital tract]

Ectopias of female genital tissues are a common event in routine pathology. Mostly they derive from paramesonephric tissues displaced during embryonal development or later. However, gonadal-, mesonephric-, or mesothelial-derived tissues may also appear in unusual localizations in and outside the female genital tract. They may be the source of benign and malignant tumors or tumor-like lesions. This review aims to provide an overview of possible tissue ectopias and to improve the developmental understanding of tumorous diseases of the female genital tract. Ectopias of primarily extragenital tissues in the female genital tract are also reviewed.

Adenomatoid tumors of the male and female genital tract are defined by TRAF7 mutations that drive aberrant NF-kB pathway activation

Adenomatoid tumors are the most common neoplasm of the epididymis, and histologically similar adenomatoid tumors also commonly arise in the uterus and fallopian tube. To investigate the molecular pathogenesis of these tumors, we performed genomic profiling on a cohort of 31 adenomatoid tumors of the male and female genital tracts. We identified that all tumors harbored somatic missense mutations in the TRAF7 gene, which encodes an E3 ubiquitin ligase belonging to the family of tumor necrosis factor receptor-associated factors (TRAFs). These mutations all clustered into one of five recurrent hotspots within the WD40 repeat domains at the C-terminus of the protein. Functional studies in vitro revealed that expression of mutant but not wild-type TRAF7 led to increased phosphorylation of nuclear factor-kappa B (NF-kB) and increased expression of L1 cell adhesion molecule (L1CAM), a marker of NF-kB pathway activation. Immunohistochemistry demonstrated robust L1CAM expression in adenomatoid tumors that was absent in normal mesothelial cells, malignant peritoneal mesotheliomas and multilocular peritoneal inclusion cysts. Together, these studies demonstrate that adenomatoid tumors of the male and female genital tract are genetically defined by TRAF7 mutation that drives aberrant NF-kB pathway activation.

A Case Report of an Adenomatoid Tumor of the Uterus Mimicking an Endometrioid Adenocarcinoma on Endometrial Curetting: a Diagnostic Pitfall

Adenomatoid tumors (AT) arising in the female genital tract are usually incidental findings occurring most often in the fallopian tube and uterine serosa and rarely in the myometrium. In the myometrium, they appear grossly as deep seated, small, firm, ill circumscribed nodules mimicking leiomyoma. Histologically they show a glandular and invasive pattern making well-differentiated/low-grade endometrioid adenocarcinoma a major differential diagnosis. However, this differential is rarely encountered in practice because myometrial AT is usually seen on the hysterectomy specimen, because of their anatomic position in the deep myometrium, and only rarely in endometrial curettings. Our case is the first to report an AT, which presented as a polyp with associated fibroid on hysterescopic examination. Microscopically, the endometrial curetting and myomectomy showed irregular glands and cystic structures with occasional cytokeratin positive single signet-ring like cells invading into the myometrium, features consistent with low-grade endometrioid adenocarcinoma. On hysterectomy specimen, there was an ill-defined 5 cm mass in the myometrium with protrusion into the endometrium. The morphology was similar to that seen in the endometrial curetting. A larger panel of immunostains was done and the neoplastic cells were positive for AE1/3, CK7, CAM5.2, calretinin, and D2-40 and negative for CD34. A diagnosis of AT was rendered and no further treatment was required. Although AT is rarely seen in endometrial curetting, they should be in the differential diagnosis of glandular lesions to avoid pitfalls and unnecessary management especially in young patients desiring fertility.

Ovarian Adenomatoid Tumor Coexisting with Mature Cystic Teratoma: A Rare Case Report

Adenomatoid tumor of the ovary is rare, and so are collision tumors in this location. The most common histological combination of ovarian collision tumors is the coexistence of mature cystic teratoma with ovarian cystadenoma or cystadenocarcinoma. Presented herein is a rare case of ovarian adenomatoid tumor found incidentally and coexisting with mature cystic teratoma. A 44-year-old woman presented with a one-year history of intermittent right-sided pelvic pain. Ultrasound evaluation revealed a heterogeneous cystic mass in the right ovary, and a clinical diagnosis of teratoma was made. The patient subsequently underwent a right salpingo-oophorectomy. Pathological examination revealed a mature cystic teratoma and coexistent adenomatoid tumor. The two tumors were separate and no transitional features were recognized histologically. To our knowledge, no previous report of coexistence of these two tumors has been reported. Both tumors are benign and completely excised; therefore no adverse consequences are expected.

Epididymal Adenomatoid Tumor: A Very Rare Paratesticular Tumor of Childhood

Adenomatoid tumor is an uncommon benign mesothelial neoplasm, usually localized in the epididymis. It is the most common paratesticular tumor of middle-aged patients (average age of clinical presentation: 36 years). However, these tumors in pediatric and pubertal patients are extremely rare. Due to their rarity, we present a case of adenomatoid tumor of the tail of the epididymis in a 16-year-old patient. After systematic research of the current literature, we did not find another case report of epididymal adenomatoid tumor in a male patient aged 16 years old or less. This notice and our concern, as well, about the patient's surveillance protocol during the postoperative period were the motive for this case study.

Uterine Adenomatoid Tumors: A Study of Five Cases Including Three Cases of the Rare Leiomyoadenomatoid Variant

OBJECTIVE

Adenomatoid tumor is a benign neoplasm of mesothelial origin encountered most often in the male and female genital tracts. This tumor has a distinct morphology and is characterized by anastomosing and variably sized tubules lined by epithelioid and flattened cells. Only 4 cases of the extremely rare leiomyoadenomatoid variant are on record. We report 5 cases of adenomatoid tumor including 3 cases of leiomyoadenomatoid tumor of the uterus, which is an extremely rare variant of adenomatoid tumor, difficult to recognize on morphology.

METHOD

A detailed histopathological review of all the uterine tumor diagnosed as fibroid and adenomatoid tumor over the period of 4 years was done.

RESULTS

A total of 5 cases of adenomatoid tumor were documented including 3 cases of leiomyoadenomatoid variant.

CONCLUSION

Leiomyoadenomatoid variant of adenomatoid tumor often missed both on imaging and histopathological examination and hence needs to be recognized as a distinct morphological entity.

Expression and diagnostic values of calretinin and CK5/6 in cholangiocarcinoma

BACKGROUND

Mesothelin, a mesothelial marker, has been found expressed in and as a potential treatment target of cholangioacarcinoma (CC). It is possible that CC may be derived from the cells sharing mesothelial markers. However, the expression of other mesothelial markers in CC is largely unknown.

METHODS

Thirty CC cases (10 extrahepatic and 20 intrahepatic) were retrieved from our institutional archive. The immunohistochemical study of Calretinin (DC8), WT1 (6F-H2), Lymphatic Endothelial Marker (D2-40), CK5/6 (D5/16 B4) and CK19 (b170) was done on formalin fixed paraffin embedded sections for 2-3 blocks of each case. We compared the expression levels between CC and normal bile duct (NBD) on the same block.

RESULTS

All of the CC and NBD are positive for CK19 (23/23) and negative for WT1 (0/23) and D2-40 (0/23), except one CC positive for D2-40(1/30, 3.3%) and one NBD positive for WT1 (1/23, 4.3%). Calretinin immunoreactivity was detected in 52.2% (12/23) of CC, but none in NBD (0/23). CK5/6 was also detectable in 73.3% (22/30) of CC and all NBD (30/30). Increased expression of calretinin and reduced expression of CK5/6 were more likely associated with CC than NBD (P < 0.001 and P = 0.002, respectively). The sequential staining pattern of positive calretinin and negative CK5/6 in calretinin negative cases has a sensitivity of 69.57% and a specificity of 100% for differentiating CC from NBD. CK5/6 expression was also more likely associated with well-differentiated CC (7/7 versus 12/20 in moderately differentiated, and 9/10 in poorly differentiated, P = 0.019) and extrahepatic CC (10/10 versus 12/20 in intrahepatic, P = 0.029), but there was no association between the calretinin expression and the CC grade or location.

CONCLUSION

Calretinin and CK5/6 immunohistochemical stains may be useful for diagnosing a CC. Their immunohistochemical results should be interpreted with caution in the cases with differential diagnoses of mesothelioma and CC. A full mesothelioma panel, including WT1 and/or D2-40, is recommended to better define a mesothelial lineage. The biology of calretinin and CK5/6 expression in CC is unclear, but might shed light on identifying therapeutic targets for CC.

True incidence of uterine adenomatoid tumors

Uterine adenomatoid tumors (UATs) are benign tumors of the uterine serosa and myometrium that originate from the mesothelium and forming gland-like structures. This study was conducted in order to determine the true incidence of UATs, which are usually an incidental finding during uterine surgery performed for other causes. UATs may resemble pre-existing vessels and lymphatic ducts, as well as metastatic adenocarcinomas. A total of 199 consecutive surgical operations (134 hysterectomies and 65 uterus-preserving tumor excisions) were performed by a single team of gynecologists and examined by a single attending pathologist, who performed a thorough macro- and microscopic examination of all the specimens. UATs were identified in nine (5%) out of the 199 cases [six (5%) out of the 134 hysterectomies and three (5%) out of the 65 uterus-preserving tumor excisions]. Therefore, the true incidence of UATs may be significantly higher than 1%, which is the incidence reported in the presently available literature.

Adenomatoid Tumor of the Testis With Intratesticular Growth

Adenomatoid tumor of the male genitourinary tract is a rare benign neoplasm thought to be of mesothelial origin. In exceptional cases, these lesions may involve the testicular parenchyma, of which there are only 9 published cases in the literature. The authors describe a rare case of a testicular tumor in a 41-year-old male with normal tumor markers. Histopathology and immunohistochemical studies revealed an adenomatoid tumor with intratesticular growth. No involvement of the epididymis or testicular membranes was identified. The morphological clues leading to the correct diagnosis of adenomatoid tumor and the possible histogenesis and differential diagnosis are discussed.

Adenomatoid tumors of the female and male genital tract. A comparative clinicopathologic and immunohistochemical analysis of 47 cases emphasizing their site-specific morphologic diversity

Adenomatoid tumors (ATs) are uncommon benign mesothelial tumors with a predilection for the genital tract. We reviewed 47 ATs diagnosed at our institutions during 10-year period. Thirty tumors (64%) originated in the female (21 uterine, 8 tubal, and 1 ovarian) and 17 (36%) in the male (9 epididymal and 8 testicular) genital tract. The median age for females and males was 47.5 and 51 years, respectively. While 83% of tumors in females were incidental findings in resections for unrelated diseases, 94% of male lesions presented as clinical masses leading to surgery. The median size was 2, 1, and 0.5 cm for uterine, epididymo-testicular, and tubo-ovarian lesions, respectively. Architecturally, the microcystic/angiomatoid pattern was the most frequent (32/47; 68%), followed by combined microcystic/trabecular (26/47; 55%) and retiform/adenoid (15/47; 32%) pattern. The trabecular/solid (6%) and macrocystic (4%) patterns were uncommon. However, 57% of cases revealed ≥2 growth patterns. Taken by anatomic site, 20 of 21 uterine cases were at least focally microcystic but none was retiform. In contrast, the retiform pattern dominated in male genital tract tumors (12/17; 71%). Immunohistochemistry showed expression of calretinin (36/36) and D2-40 (30/30) and lack of CD34 (0/30) and PAX8 (0/32). GLUT-1 was expressed in 11/11 male genital tract tumors but in none of the microcystic uterine lesions. Estrogen and progesterone receptor expression was weak and focal (two and three uterine cases, respectively). None stained for the androgen receptor. Our study illustrates the great site-specific morphological diversity of ATs emphasizing their wide site-dependent differential diagnosis.