Primary adenomatoid tumor of the adrenal gland: A case report and literature review.

RATIONALE: Adenomatoid tumors are rare benign tumors, mainly involving the reproductive tract, such as the epididymis in men and the uterus and fallopian tubes in women. However, a few cases can occur outside the reproductive tract. Herein, we report a rare case of a primary adenomatoid tumor of the adrenal gland. PATIENT CONCERNS: A 50-year-old man underwent ultrasound examination and was found to have a right adrenal mass without elevated blood pressure, weakness after fatigue, frequent nocturnal urination urgency, pain, or a history of hematuria. The patient's general health was normal. Computed tomography revealed a polycystic mixed-density lesion in the right adrenal region, approximately 7.3 × 4.5 cm in size. DIAGNOSES: Based on the clinical information, morphological features, and immunohistochemistry results, a pathological diagnosis of primary adenomatoid tumor of the adrenal gland was made. INTERVENTION: Excision of the right adrenal gland and tumor through the 11 ribs. OUTCOMES: The patient's postoperative course was uneventful. LESSONS: Preventing misdiagnosis adenomatoid tumors with other types of adrenal gland tumors or metastatic tumors is imperative. Morphological and immunohistochemical features can help diagnose primary adenomatoid tumors of the adrenal gland.

Multiparametric Ultrasound Diagnostic Approach to Malignancy-Mimicking Adenomatoid Tumors of the Scrotum: Is Strain Elastography Enough?

Background: Paratesticular tumors (PTs) are very uncommon, accounting for almost 5% of intrascrotal tumors. Of these, adenomatoid tumors (ATs) represent about 30% and most frequently arise in the tail of the epididymis. Ultrasound (US) examination is the first-choice imaging method employed for the evaluation of the scrotum. Unfortunately, there are no specific US-imaging features useful for distinguishing an AT from a malignant lesion. To increase diagnostic accuracy and confidence, new sonographic techniques have incorporated real-time tissue elastography (RTE) under the assumption that malignant lesions are "harder" than benign lesions. Case report: In our paper, we describe a very rare case of a 60-year-old patient with a giant paratesticular mass mimicking malignancy when examined using RTE, i.e., it was stiffer than the surrounding tissue (a hard pattern), which, upon histologic examination, was identified as an AT. Discussion: Our case underscores that there is also a significant overlap between different types of scrotal lesions when RTE is used for examination. Thus, if a PT is found, the imaging approach should always be supplemented with more definitive diagnostic methods, such as FNAC or FNAB, which are the only diagnostic methods capable of leading to a certain diagnosis. Conclusions: Alongside underlining the importance of pre-operative imaging for making correct diagnoses and selecting the correct therapy, we wish to draw our readers' attention to this report in order to demonstrate the clinical implications of a giant AT presenting as stiff lesions when examined using SE.

Mesotheliomas and Benign Mesothelial Tumors: Update on Pathologic and Imaging Findings.

A diverse spectrum of benign entities and malignant neoplasms originate from the monotonous mesothelium that lines the serosal membranes of the pleural, pericardial, and peritoneal cavities. The mesothelium of myriad sites shows a common origin from the lateral plate mesoderm; primary mesothelial tumors thus demonstrate similar pathogenesis, imaging findings, and treatment options. Significant changes have been made in the 2021 World Health Organization (WHO) classification schemata of the pleural and pericardial tumors on the basis of recent advances in pathology and genetics. While malignant mesotheliomas are biologically aggressive malignancies that occur primarily in patients exposed to asbestos with attendant poor survival rates, well-differentiated papillary mesothelial tumors and adenomatoid tumors charter a benign clinical course with an excellent prognosis. Mesothelioma in situ is a newly characterized entity represented by recurrent unexplained pleural effusions without any identifiable mass at imaging or thoracoscopy. Immunohistochemical markers based on BAP1, MTAP, CDKN2A, and TRAF7 gene mutations help differentiate diffuse mesotheliomas from benign mesothelial proliferations and localized mesotheliomas. Cross-sectional imaging modalities, including US, CT, MRI, and fluorine 18-fluorodeoxyglucose (FDG) PET/CT, permit diagnosis and play a major role in staging and assessing surgical resectability. Imaging studies are invaluable in providing noninvasive and quantitative assessment of tumor response in patients with unresectable disease. Owing to significant overlap in patient characteristics and pathomorphology, accurate diagnosis based on advanced histopathology techniques and genetic abnormalities is imperative for optimal management and prognostication. While patients with nonepithelioid pleural mesotheliomas benefit from immunotherapy, novel targeted therapies for CDKN2A-, NF2-, and BAP1-altered mesotheliomas are under consideration. © RSNA, 2023 Quiz questions for this article are available through the Online Learning Center.

A Rare Pancreatic Tumor with Adenomatoid Tumor-like Findings.

A 74-year-old woman was referred to our hospital for the evaluation of slightly elevated tumor marker levels. Computed tomography revealed a well-demarcated tumor, approximately 15 mm in diameter, in the pancreatic tail. Endoscopic ultrasound-guided fine-needle aspiration findings suggested poorly differentiated cancer. The tumor was surgically resected, but postoperative pathologic confirmation was not possible. After one year without treatment and no recurrence, an evaluation by a specialized facility was requested for a definitive diagnosis. Adenomatoid tumor was deemed most likely based on the histopathology and immunostaining findings; however, a definitive diagnosis was difficult because of atypical findings. The patient was recurrence-free for 36 months at the last follow-up.

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.

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.

Leiomyo-adenomatoid Tumor of the Uterus: Finding the Rare in the Routine.

Leiomyo-adenomatoid tumour (LMAT) is a rare benign neoplasm and very few cases of LMAT of the uterus are documented in the literature. Uterine LMATs are usually detected incidentally during the histopathologic evaluation of routine myomectomy or hysterectomy specimens for leiomyomata. Thorough evaluation of the morphological features and a concise immunohistochemical panel allows for accurate classification of this benign neoplasm.

Ultrasonographic misdiagnosis of multicystic mesothelioma of the omentum: A case report.

RATIONALE: Multicystic Mesothelioma (MM) is very rare and preoperative diagnosis is difficult. PATIENT CONCERNS: We report a case of a 34-year-old man with solid abdominal cystic echo mass. Physical examination showed that the patient had a flat and soft abdomen without tenderness or rebound pain, no fluid wave tremor, and no obvious abdominal mass was touched. The patient complained of repeated abdominal distention with nausea for 5 days. Sonographic examination suspected pseudomyxoma peritoneum. DIAGNOSIS: Conventional ultrasound examination showed a cystic solid echo mass in the right abdominal cavity of the patient, with uneven internal echo and honeycomb change, and clear boundary with surrounding organs. Color Doppler suggested that the blood flow in the mass was not obvious. Contrast-enhanced computed tomography of the abdomen revealed hypodensity foci in hepatic and renal crypts and right paracolic sulcus. INTERVENTIONS: Laparoscopic resection of the mass was performed, and the postoperative pathological findings were polycystic mesothelioma (greater omentum). OUTCOMES: After mass resection, all laboratory tests and abdominal ultrasound were normal, and abdominal distension and nausea disappeared. LESSONS: Improved ultrasound diagnosis of MM is useful for clinical decision-making.

Adenomatoid mesothelioma arising from the diaphragm: a case report and review of the literature.

BACKGROUND: Adenomatoid mesothelioma is a rare subtype of malignant mesothelioma that can be confused with adenomatoid tumors, which are classified as benign. The clinical features and optimal management of adenomatoid mesothelioma have not been elucidated in the literature. In this report, we present an extremely rare case of adenomatoid mesothelioma that developed on the peritoneal surface of the diaphragm as well as a literature review of adenomatoid mesothelioma in the abdominal cavity. CASE PRESENTATION: The patient was a 61-year-old Japanese woman who had undergone resection of a malignant peripheral nerve sheath tumor of the hand 18 years prior. She was diagnosed with clinical stage I lung adenocarcinoma on follow-up chest radiography. Simultaneously, a 20-mm enhancing nodule with slow growth on the right diaphragm was detected on contrast-enhanced computed tomography. She presented no specific clinical symptoms. At this point, the lesion was suspected to be a hypervascular tumor of borderline malignancy, such as a solitary fibrous tumor. After a left upper lobectomy for lung adenocarcinoma, she was referred to our department, and laparoscopic tumor resection was performed. Adenomatoid tumors were also considered based on the histopathological and immunohistochemical analyses, but we made the final diagnosis of adenomatoid mesothelioma using the results of the genetic profile. The patient remains alive, with no recurrence noted 6 months after surgery. CONCLUSION: We encountered a valuable case of adenomatoid mesothelioma of peritoneal origin. There are some previously reported cases of adenomatoid mesothelioma and adenomatoid tumors that may need to be recategorized according to the current classification. It is important to accumulate and share new findings to clarify the clinicopathological characteristics and genetic status of adenomatoid mesothelioma.

Molecular and immunohistochemical characterisation of mesothelioma of the tunica vaginalis.

AIMS: Malignant mesothelioma (MM) of the tunica vaginalis (TV) is a rare and aggressive tumour, and the molecular features and staining profile with contemporary immunohistochemical (IHC) biomarkers are largely unexplored. We characterise the clinicopathological, molecular and IHC features of MM (n = 13) and mesothelial neoplasms of uncertain malignant potential (MUMP) (n = 4). METHODS AND RESULTS: Targeted next-generation sequencing was performed on seven MMs and two MUMPs. IHC was performed for methylthioadenosine phosphorylase (MTAP), BRCA1-associated protein 1 (BAP1) and SRY-box transcription factor 6 (SOX6). Thirteen adenomatoid tumours were also assessed with SOX6. MM were epithelioid (seven of 13) or biphasic (six of 13). In MM, NF2 (five of seven; 71%), CDKN2A (three of seven; 43%) and BAP1 (two of seven; 29%) were most frequently altered. Non-recurrent driver events were identified in PTCH1 and TSC1. In contrast, none of these alterations were identified in MUMPs; however, one MUMP harboured a TRAF7 missense mutation. By IHC, loss of MTAP (two of 12; 17%) and BAP1 (two of nine; 22%) was infrequent in MM, whereas both were retained in the MUMPs. SOX6 was positive in nine of 11 (82%) MMs and negative in all MUMPs and adenomatoid tumours. CONCLUSIONS: Testicular MM exhibit a similar mutational profile to those of the pleura/peritoneum; however, alterations in CDKN2A and BAP1 are less common. These findings suggest that although MTAP and BAP1 IHC are specific for MM, their sensitivity in testicular MMs appears lower. In addition, rare tumours may harbour targetable alterations in driver genes (PTCH1 and TSC1) that are unusual in MMs at other anatomical sites. SOX6 is sensitive for MM; accordingly, the presence of SOX6 expression argues against a benign neoplastic process.

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 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 Tumors of the Uterus: A Case Report and Literature Review.

BACKGROUND An adenomatoid tumor is a benign neoplasm that originates in the mesothelial lining, commonly present in the male and female genital tracts. The lieomyoadenomatoid tumor (LMAT) is rare and considered an adenomatoid variant, characterized microscopically by prominent smooth muscle proliferation within an adenomatoid tumor. Areas of pseudo-glandular infiltration and tubular and slit-like spaces can mimic metastatic carcinoma or malignant tumors. Most cases of LMAT were incidentally discovered microscopically after an impression of leiomyoma. Eighteen cases have been reported in studies published in English. CASE REPORT We present a case of a 35-year-old woman who experienced recurrent vaginal bleeding and underwent a myomectomy. Microscopically, the mass showed smooth muscle proliferation in fascicles with areas of tubular, slit-like spaces, and gland-like areas, which showed reactivity for Wilms tumor-1 and calretinin by an immunohistochemistry study. The final pathology examination showed a 9-cm LMAT, which is the largest size ever reported to the best of our knowledge. There was no recurrence or other symptoms at the 2-year follow-up. CONCLUSIONS An LMAT should be considered in the differential diagnosis of leiomyomas that present areas of pseudo-infiltrative glands and slit-like spaces, which can lead to misdiagnosis as a malignant tumor.

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.

[Adenomatoid tumor of the adrenal gland: Clinicopathologic characteristics and differential diagnosis on two tumors of exceptional adrenal location]. / Tumeur adénomatoïde de la surrénale : aspects clinico-pathologiques et diagnostics différentiels de deux tumeurs de localisation surrénaliennes exceptionnelles.

Adenomatoid tumors are benign tumors from mesothelial origin, usually occurring in the genital tract. Extragenital locations, especially in the adrenal gland are extremely rare. Here we are reporting two cases of a 28-year-old and 50-year-old men with an adenomatoid tumor of the right adrenal gland. Usual morphological aspects join scattered and microcystic pattern with epithelioid or signet-ring cells. According to the morphological features, main differential diagnoses are adenocarcinoma metastasis, vascular tumors or mesotheliomas. Immunohistochemistry provides precious help to confirm the mesothelial origin thanks to positivity of epithelial markers (CK7, AE1-AE3, CK5/6) coupled to mesothelial markers (D2-40, Calretinin, WT1). On the other hand, there is no loss of BAP1 by immunohistochemistry and usually a surexpression of P16. Adrenal gland adenomatoid tumor is a benign tumor, which can be promoted by iatrogenous or constitutive immunodepression.