Extragenital adenomatoid tumor of a mediastinal lymph node

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.

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.

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.

Adenomatoid tumor of the skin: Differential diagnosis of an umbilical erythematous plaque

Adenomatoid tumors are benign tumors of mesothelial origin that are usually encountered in the genital tract. Although they have been observed in other organs, the skin appears to be a very rare location, with only one case reported in the literature to our knowledge. We report a second case of an adenomatoid tumor, arising in the umbilicus of a 44-year-old woman. The patient presented with an 8-month-old erythematous and firm plaque under the umbilicus. A skin biopsy showed numerous microcystic spaces dissecting a fibrous stroma and lined by flattened to cuboidal cells with focal intraluminal papillary formation. This little-known diagnosis constitutes a diagnostic pitfall for dermatopathologists and dermatologists, and could be misdiagnosed as other benign or malignant entities. Through this case report, a practical approach and diagnostic keys have been devised to avoid misdiagnosis and overtreatment.

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.

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.

Posterior Mediastinal Adenomatoid Tumor: A Case Report and Review of the Literature

Adenomatoid tumor is an uncommon benign neoplasm of mesothelial differentiation that distinctively arises in and around the genital organs. In rare instances, it has been described in extragenital locations. There have been only two reports documenting its occurrence in the anterior mediastinum, and no reports documenting its occurrence in the posterior mediastinum. We report the first case of posterior mediastinal adenomatoid tumor. A 37-year-old Caucasian woman presented with symptoms of bronchitis. Imaging studies identified a 2.0 cm posterior mediastinal mass abutting the T9 vertebral body, clinically and radiologically most consistent with schwannoma. Histologic sections revealed a lesion composed of epithelioid cells arranged in cords and luminal profiles embedded in a fibrotic to loose stroma and surrounded by a fibrous pseudocapsule. Lesional cells showed vacuolated eosinophilic cytoplasm and peripherally displaced nuclei with prominent nucleoli. There was focal cytologic atypia but no mitotic figures or necrosis was identified. The lesional cells expressed cytokeratin, calretinin, and nuclear WT1 but were negative for PAX8, TTF1, p53, chromogranin, CD31, and CD34, and Ki67 showed <2% proliferation rate, diagnostic of adenomatoid tumor. Three years after resection, the patient is in good health without tumor recurrence. Thus, our encounter effectively expands the differential diagnosis of posterior mediastinal neoplastic entities.

Adenomatoid tumor of the small intestine: the first case report and review of the literature

The case represents the first literature report of an adenomatoid tumor that arises primarily in the small intestine of a 44-year-old woman, who presented with intermittent upper abdominal pain accompanied by nausea and vomiting. The resected tumor was grossly unencapsulated and had a gray-tan color on its cut surface. Microscopically, it consisted of variably sized tubules and glandular spaces which involved the whole layers of the intestine. The mesothelial nature of the lesion was subsequently verified by the immunopositivity for pancytokeratin (AE1/AE3), HBME-1, calretinin, D2-40, and WT1 with cells lining the tubules and glandular spaces. Albeit very rare, adenomatoid tumor should be included in the differential diagnosis of tubular or glandular tumors occurring in the small intestine.

Transmural peritoneal adenomatoid tumour in the ileocaecal region causing massive haemoperitoneum and low gastrointestinal bleeding: differential diagnosis with capillary haemangiomas

Peritoneal adenomatoid tumours are rare benign neoplasms originating from mesothelial cells. We present a case of peritoneal adenomatoid tumour penetrating into the bowel wall and causing massive intra- and extraluminal bleeding.

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.

Leiomyo-adenomatoid tumor of the uterus: a distinct morphological entity?

INTRODUCTION

The morphologic and immunohistochemical findings of a well-circumscribed leiomyoadenomatoid tumor located in the posterior uterine wall are reported.

CASE REPORT

The patient was a 55-year-old white woman who complained of peri/postmenopausal and irregular bleeding during the past 4 months. The adenomatoid component was intermingled with bland smooth muscle fascicles and was composed of vacuolated cells, tubules, and slit-like structures crossed by epithelial bridges. Immunohistochemistry revealed positivity to epithelial and mesothelial markers in the adenomatoid component and strong immunoreaction for smooth muscle markers in the leiomyomatous one.

CONCLUSIONS

The well-defined circumscription and the presence of mesothelial component intermingled with the leiomyomatous proliferation favors the hypothesis that a leiomyo-adenomatoid tumor should be considered as a subtype of adenomatoid tumor with distinctive morphological features. Only four previous cases of this rare neoplasm have been reported to date, one in the epydidimis and the other three cases in the uterine wall, one of them affecting also to the right ovary.

Cystic lymphangioma-like adenomatoid tumor of the adrenal gland: Case presentation and review of the literature

Adenomatoid tumors (AT) are usually found in the genital tract of both sexes. They are very rarely located in extragenital sites, and are exceedingly rare in the adrenal. AT of the adrenal gland (AT-AG) are nonfunctioning, usually discovered incidentally and confused on imaging with other more common adrenal neoplasms. The overwhelming majority occur in males. Thirty-four cases have been reported so far, more often presenting grossly as solid tumors, rarely as solid with cystic areas, and 5 cases were almost entirely cystic. At histology they can be either circumscribed or locally infiltrative, and may pose diagnostic difficulties when the pathologist relies on morphology alone or is challenged on frozen section. On light microscopy the diagnosis may be very difficult if the tumor is rich in vacuolated cells, mimicking metastatic signet ring-cell adenocarcinoma. Immunophenotyping and/or electron microscopy are paramount in helping to ascertain their mesothelial lineage. Lymphangioma is the main histologic mimic of solid-cystic and cystic AT-AG, but lymphangioma is immunopositive for endothelial markers and negative for cytokeratins and mesothelial markers. Ultrastructural analysis has been performed in 10 published cases of AT-AG, in all of which the classical microvilli of coelomic type were always observed. In brief we report herein the sixth case of cystic lymphangioma-like AT, which was incidentally discovered during clinical follow-up in a 39-year-old man undergoing cancer staging and surveillance after surgery. The adrenal tumor was 5.5 cm in size and was fully investigated immunohistochemically and ultrastructurally. A complete review of the literature is also presented.

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

Adenomatoid tumors of the female and male genital tracts are well characterized as mesothelial in origin, but a detailed histological and immunohistochemical analysis comparing both traditional and newer mesothelial markers across gender and site has not been formally conducted. A variety of morphologic features previously described as characteristic of adenomatoid tumors were evaluated in 44 adenomatoid tumors from the male and female genital tracts. Immunohistochemical analysis with pankeratin (AE1/CAM5.2), WT-1, calretinin, CK5/6, D2-40, and caldesmon was also performed. The extent and intensity of staining were scored semiquantitatively on one representative section per case and mean value for each parameter was calculated. All (n=44) the adenomatoid tumors from both the female and male genital tracts demonstrated a distinctive thread-like bridging strand pattern. Lymphoid aggregates were seen in all 12 adenomatoid tumors of male patients, but in only 4 of 32 (13%) tumors in female patients (P<0.0001). The remaining morphologic features were variably present with no clear sex predilection. Pankeratin, calretinin, and D2-40 reactivity were identified in all female (n=32) and male (n=12) genital tract adenomatoid tumors. Adenomatoid tumors expressed WT-1 in 11/12 (92%) male patients and in 31/32 (97%) female patients. In male patients, reactivity for CK5/6 and caldesmon was found in 1/12 (8%) and 0/12 (0%) adenomatoid tumors (respectively), whereas reactivity in female patients was found in 5/32 (16%) and 1/32 (3%); respectively. Female tumors differ from their male counterparts by the frequent absence of lymphoid aggregates and the presence of a circumscribed margin when occurring in the fallopian tube. Of the putative mesothelial markers evaluated, calretinin, D2-40, and WT-1 show a similar immunoprofile and have a higher sensitivity than CK5/6 and caldesmon in genital tract adenomatoid tumors. However, the presence of additional, often strong expression of WT-1 in normal tissues of the female genital tract limits the utility of WT-1 in this setting.

Myocardial Adenomatoid Tumor in Eight Cattle: Evidence for Mesothelial Origin of Bovine Myocardial Epithelial Inclusions

The adenomatoid tumor is an uncommon benign lesion, thus far described only in humans. Adenomatoid tumors typically arise in the genital tract, exceptionally in the heart, and usually represent an incidental finding. Microscopically, they are constituted by epithelioid cells that form tubular structures and anastomosing channels within a fibrous stroma. Mesothelial origin of these lesions is suggested by their immunohistochemical characteristics. In cattle, previously reported myocardial epithelial inclusions are morphologically similar in that the cells are immunoreactive for both cytokeratins and vimentin, and bear surface microvilli. Myocardial lesions found incidentally at slaughter in 8 cattle histologically resembled the so-called bovine myocardial epithelial inclusions and had morphologic and immunohistochemical features consistent with human adenomatoid tumor. All lesions were in the left ventricular myocardium, adjacent to the epicardium, and composed of epithelioid cells that formed cords and tubules, and were immunoreactive for pan-cytokeratins, cytokeratin 5/6, vimentin, calretinin, Wilms' tumor 1 suppressor gene, and CD30 antigen. By electron microscopy, numerous long slender microvilli were associated with desmosomes and tonofibrils. The immunohistochemical and ultrastructural features were considered consistent with mesothelial origin. These lesions, corresponding to the previously described myocardial epithelial inclusions in cattle, might be considered embryologic rests and could represent the bovine counterpart of the human adenomatoid tumor.

Adenomatoid tumor of the adrenal gland: case report with immunohistochemical study

Adrenal adenomatoid tumor (AT) is a recently recognized disease with marked male predominance. Herein is presented a case of adrenal AT incidentally found in a 30-year-old man and results of immunohistochemical examination of the tumor. The left adrenal gland, weighing 17 g, contained a mass measuring 3 x 2.5 x 2.5 cm in the cortical tissue. Cut surface showed a relatively well-circumscribed firm tumor with a white solid appearance. Histologically, the tumor had the typical appearance of AT described in the genital tract. Immunohistochemically, the tumor cells were positive for calretinin, D2-40, WT1, mesothelial cell antigen, CA125, thrombomodulin, vimentin and cytokeratins (stained by AE1 + AE3, OV-TL 12/30, CAM5.2 and MNF116), and negative for endothelial markers (CD31, CD34 and factor VIII-related antigen) and CD56. CD56-positive adrenocortical cells were diffusely scattered in the tumor, especially in its periphery. Immunohistochemistry of estrogen, progesterone and androgen receptors was negative. These findings confirm mesothelial origin of the tumor and suggest that this tumor has little relation to sex hormone despite male predominance.

Adenomatoid tumor of the adrenal gland: a clinicopathologic study of 3 cases

Adenomatoid tumors are relatively uncommon benign neoplasms of mesothelial origin, usually occurring in the male and female genital tracts. Rare extragenital adenomatoid tumors have been identified in the adrenal glands, heart, mesentery, pleura, and lymph nodes. In the adrenal gland, adenomatoid tumors may pose a diagnostic challenge. The differential diagnosis includes adrenocortical carcinoma and metastatic carcinoma, especially signet ring cell carcinoma. Because of its glandular pattern, an adenomatoid tumor may be confused with an adenocarcinoma. We present 3 cases of adrenal adenomatoid tumors, including one with a concurrent large hemorrhagic vascular adrenal cyst. The adenomatoid tumors were unilateral, appeared solid and white, and varied from 1.7 to 4.2 cm in diameter. They occurred in 3 male patients aged 33, 33, and 46 years. One patient presented with abdominal pain due to the presence of a concurrent large adrenal cyst. The tumor was an incidental radiological finding in another case and was discovered during the course of a workup for hypertension in the third case. The light microscopic appearances were consistent with those of typical adenomatoid tumors. Immunohistochemical stains for calretinin and cytokeratin 5/6 were positive, confirming the tumors' mesothelial origin. Ultrastructural studies performed in 2 cases revealed microvilli and desmosomes. Follow-up showed no evidence of recurrence or metastasis. In our experience, the key to the diagnosis of this rare benign tumor is to consider adenomatoid tumor in the differential diagnosis of any glandular tumor occurring in the adrenal gland.

Adenomatoid Tumors of the Female and Male Genital Tracts Express WT1

Adenomatoid tumors are benign proliferations most often encountered in the female and male genital tracts. The mesothelial phenotype of these unusual tumors has been established by a variety of ultrastructural and immunohistochemical studies, although their etiology is by no means certain. The expression of the Wilms' tumor suppressor gene, WT1, in normal, hyperplastic, and malignant mesothelial cells prompted us to analyze the expression pattern of WT1 in a series of 24 adenomatoid tumors occurring in the uterus, fallopian tube, ovary, epididymis, scrotum, and testis. Twenty-three of the tumors expressed WT1 protein and the same number expressed calretinin, another marker of mesothelial differentiation. The one tumor that failed to stain with calretinin was positive for WT1. These results provide further support for mesothelial differentiation of adenomatoid tumors and suggest that the presence of WT1 expression may be useful in the differential diagnosis of these uncommon neoplasms, especially when they present in unusual settings or expression of other mesothelial markers is absent.