Benign müllerian glandular inclusions in men undergoing pelvic lymph node dissection

Benign Islet Cells Within Peripancreatic Lymph Nodes: A Potential Diagnostic Pitfall

The presence of epithelial cells within lymph node parenchyma is typically indicative of a metastatic malignancy. However, there are rare instances in which non-neoplastic epithelial or epithelioid cells may be found within lymph nodes, either due to aberrant embryologic migration, mechanical displacement, or physiological trafficking. These can potentially lead to serious potential diagnostic pitfalls, as when such situations are encountered by surgical pathologists, there is substantial risk of overdiagnosing these as metastatic malignancy. Herein, we describe 2 cases of benign pancreatic islet cells within peripancreatic lymph nodes, and underscore the potential for misdiagnosis of this phenomenon as foci of metastatic well-differentiated neuroendocrine tumor. The benign nature of these intranodal islet cells was supported by: (1) the absence of a well-differentiated neuroendocrine tumor in the entirely submitted concomitant pancreatic resection specimen and (2) the presence of an admixture of insulin and glucagon expressing cells by immunohistochemistry in a distribution characteristic of non-neoplastic pancreatic islets. Both cases were incidental microscopic findings in pancreatic resections for intraductal papillary mucinous neoplasms that were previously biopsied and showed associated microscopic areas of fibrosis and chronic pancreatitis and thus this phenomenon may be related to mechanical displacement from prior injury and/or biopsy.

The uterine secretome initiates growth of gynecologic tissues in ectopic locations

Endosalpingiosis (ES) and endometriosis (EM) refer to the growth of tubal and endometrial epithelium respectively, outside of their site of origin. We hypothesize that uterine secretome factors drive ectopic growth. To test this, we developed a mouse model of ES and EM using tdTomato (tdT) transgenic fluorescent mice as donors. To block implantation factors, progesterone knockout (PKO) tdT mice were created. Fluorescent lesions were present after oviduct implantation with and without WT endometrium. Implantation was increased (p<0.05) when tdt oviductal tissue was implanted with endometrium compared to oviductal tissue alone. Implantation was reduced (p<0.0005) in animals implanted with minced tdT oviductal tissue with PKO tdT endometrium compared to WT endometrium. Finally, oviductal tissues was incubated with and without a known implantation factor, leukemia inhibitory factor (LIF) prior to and during implantation. LIF promoted lesion implantation. In conclusion, endometrial derived implantation factors, such as LIF, are necessary to initiate ectopic tissue growth. We have developed an animal model of ectopic growth of gynecologic tissues in a WT mouse which will potentially allow for development of new prevention and treatment modalities.

Management of retroperitoneal high-grade serous carcinoma of unknown origin: A case report

BACKGROUND

Retroperitoneal high-grade serous carcinoma (HGSC) of unknown origin is a sporadic tumor that can originate from ovarian cancer. Herein, we report the case of a woman with retroperitoneal HGSC of unknown origin and describe how she was diagnosed and treated.

CASE SUMMARY

A 71-year-old female presented with the tumor marker CA125 elevated to 1041.9 U/mL upon a regular health examination. Computed tomography revealed retroperitoneal lymph node enlargement. Subsequently, positron emission tomography scanning revealed lesions with increased F-18 fluorodeoxyglucose uptake at the nodes. As a result, she underwent laparoscopic lymph node resection, and pathology revealed metastatic adenocarcinoma with CK7(+), PAX8(+), WT1(+), PR(-), and p53 mutational loss of expression, indicating that the origin may be from the adnexa. The patient was admitted to our ward and underwent laparoscopic staging; however, the pathological results were negative. Under the suspicion of retroperitoneal HGSC of unknown origin, chemotherapy and targeted therapy were initiated. Tumor marker levels decreased after treatment.

CONCLUSION

We present a case of HGSC of unknown origin managed using retroperitoneal lymphadenectomy, staging surgery, chemotherapy, and targeted therapy.

Primary Retroperitoneal Carcinomas: New Insights into Pathogenesis and Clinical Management in Comparison with Ovarian Carcinomas and Carcinoma of Unknown Primary

Primary retroperitoneal carcinomas are very rare tumors. Their pathogenesis remains unknown but may be associated with that of ovarian carcinomas, considering the similarity in morphology and gender preference. Although metaplasia of coelomic epithelium is the most widely accepted theory, the pathogenesis of retroperitoneal carcinomas may differ by histologic subtype, like ovarian carcinomas. Mucinous carcinoma, which develops in both women and men, may originate in both primordial germ cells and Walthard cell nests that may be derived from the fallopian tube. Serous carcinomas may be associated with endosalpingiosis, the presence of fallopian tube-like epithelium outside the fallopian tube, and a remnant Müllerian tract. Endometrioid and clear cell carcinomas appear to be associated with extraovarian endometriosis. Additionally, both carcinomas in the retroperitoneal lymph nodes may be metastatic diseases from endometrial and/or renal cell cancer that regress spontaneously (carcinoma of unknown primary). Retroperitoneal carcinomas are difficult to diagnose, as they have no characteristic symptoms and signs. Surgery is the cornerstone of treatment, but the necessity of chemotherapy may depend on histological subtype. Further studies are necessary, in particular studies on endosalpingiosis, as endosalpingiosis is a poorly understood condition, although it is associated with the development of both serous and mucinous carcinomas.

Intraoperative Appearance of Endosalpingiosis: A Single-Center Experience of Laparoscopic Findings and Systematic Review of Literature

Background: Endosalpingiosis is assumed to be the second most common benign peritoneal pathology after endometriosis in women. Although recent studies indicate a significant association with gynecologic malignancies, many underlying principles remain unclear. This work aimed to systematically describe the intraoperative appearance of endosalpingiosis. Methods: Data and intraoperative videos of patients with histologically verified endosalpingiosis were retrospectively reviewed. The main outcome measures were macroscopic phenotype and anatomical distribution. Additionally, a systematic review searching PubMed (Medline) and Embase was conducted. Results: In the study population (n = 77, mean age 40.2 years (SD 16.4)), the mean size of lesions was 3.6 mm and the main visual pattern was vesicular (62%). The most frequent localization was the sacrouterine ligaments (24.7%). In the systematic review population (n = 1174 (210 included studies overall), mean age 45.7 years (SD 14.4)), there were 99 patients in 90 different studies with adequate data to assess the appearance of the lesions. The mean size of the lesions was 48.5 mm, mainly with a cystic visual pattern (49.5%). The majority of the lesions affected the ovaries (23.2%), fallopian tubes (20.4%), or lymph nodes (18.5%). Comparing this study to the literature population, the main differences concerned the size (p < 0.001) and main visual patterns (p < 0.001) of lesions. Conclusions: The usual intraoperative findings of endosalpingiosis appeared less impressive than described in the literature. In our study population, lesions of a few millimeters in size with a vesicular appearance were mostly seen, most frequently in the sacrouterine ligament area. Intraoperative recognition by the gynecologic surgeon and histologic diagnosis should play an important role in further understanding this entity, scientifically and clinically.

Ciliated Cells in Renal Calyx mucosa: Metaplastic Change or Developmental Abnormality? Immunohistochemical Study of one Case and Review of the Literature

Ciliated epithelial cells have been rarely observed in urothelium lined mucosa. Only extremely rare reports in the literature have described this phenomenon and no cases have been described in other sites than the male urethra. Herein, we illustrate the finding of ciliated pseudostratified columnar cells in the renal calyx mucosa adjacent to an area of urothelial invasive carcinoma in an 82 year-old man with previous history of nephrolithiasis. The ciliated cells covered a linear extension of 0.5 cm: they were positive for keratin 7 and keratin 8/18 and negative for keratin 20. Alcian blue staining was positive in some vacuoles in the apical cytoplasm of the same cells whereas PAS (Periodic Acid-Schiff) staining was negative. GATA3 resulted negative in ciliated cells except for a layer in the basal portion of the epithelium, just above the basal membrane. The actual prevalence of ciliated epithelia in the urinary tract is not well documented and the current knowledge on the subject is limited to electron scanning microscopy studies. The significance of this phenomenon remains unknown: it could be either a developmental abnormality or more probably a metaplastic change. Associated urolithiasis, which has been described in both a previous report and in the present one, could hypothetically represent a possible trigger for this unusual cell change. However, this hypothesis needs to be confirmed through further investigation.

Endocervicosis in an Intramammary Lymph Node

Benign müllerian inclusions are frequently encountered within infra-diaphragmatic locations such as pelvic lymph nodes, bladder, cervix and vagina. Supra-diaphragmatic müllerian inclusions, especially endocervicosis, are exceedingly rare. We report a case of endocervicosis within an intramammary lymph node in a 49-year-old woman. To the best of our knowledge, this is the second reported case.

The History of the Discovery of Ectopic Epithelial Cells in Lower Peritoneal Organs: The So-Called Mucosal Invasion

Through microscopy, early researchers identified the epithelium on the inner surfaces of the uterus, cervix and Fallopian tubes. The identification of ectopic epithelium was gradual, starting from the gross pathology study of unusual cystic lesions. Towards the end of the nineteenth century, attention focused on the epithelium as a critical component. The term ‘adenomyoma’ was coined around eighteen eighty to designate the majority of mucosa-containing lesions. Several theories were advanced to explain its aetiology. In the main, lesions were considered to arise from invasion from uterine epithelium; implantation of endometrium through retrograde menstruation; hematogenous or lymphatic spread; or from embryonic remnants. Although initially widely rejected, around 1920, an almost unanimous consensus formed on the endometrial nature of epithelial invasions. During the following years, adenomyosis and endometriosis came to be used to distinguished lesions within or outside the uterus. Adenomyosis was attributed to direct infiltration of uterine mucosa into the myometrium, and endometriosis to the implantation of endometrial cells and stroma into the peritoneal cavity through retrograde menstruation. Around the same time, ovarian lesions, initially described as ovarian hematomas or chocolate cysts, were regarded as a form of endometriosis. Three variants of endometriosis were thus described: superficial peritoneal, deep nodular and ovarian endometriomas. Ectopic epithelium has long been recognised as having similarities to tubal, or cervical epithelium. Lesions containing mixed epithelium are often termed Müllerianosis. This article demonstrates the stepwise evolution of knowledge, the role of the pioneers and the difficulties that needed to be overcome. It also demonstrates the value of collaboration and the inter-connected nature of the scientific endeavour.

Cystic Lesion of Dissected Pararectal Lymph Node in a Female Patient With Rectal Carcinoma: A Rare Pattern of Nodal Metastasis Mimicking a Serous Inclusion Cyst

Nodal metastatic foci of colorectal carcinoma are usually solid nodules. Serous inclusions are occasionally found in lymph nodes, particularly in female patients, and they occasionally form cysts. An 86-year-old woman was treated with laparoscopic low anterior resection and D3 lymph node dissection for advanced rectal carcinoma. A cyst with serous fluid and no necrotic debris was found within one of the dissected pararectal lymph nodes. Histologically, the cyst was lined by low columnar-to-cuboid epithelium with mild nuclear atypia, mimicking a serous inclusion cyst. Immunohistochemically, the epithelial cells were positive for caudal type homeobox 2 and negative for Wilms' tumor suppressor gene1. Immunohistochemistry for p53 showed a diffuse strong positivity, indicating a mutant TP53 as seen in primary rectal carcinoma. Thus, the nodal cystic lesion was confirmed to be a metastatic lesion. It is important to carefully assess a nodal cystic lesion to confirm whether it is benign or malignant.

Uterine endosalpingiosis: Case report and review of the literature

OBJECTIVE

Endosalpingiosis rarely occurs in the uterus. We report a case and review literature to explore its current clinical diagnosis and treatment.

CASE REPORT

A 31-year-old woman was admitted to the hospital for suspected uterine leiomyoma with cystic degeneration based on ultrasound and magnetic resonance imaging and surgical treatment. Laparoscopy revealed a large cystic mass protruding from the posterior uterine wall. The mass was resected, and a histologic examination showed that the cyst wall was lined with benign fallopian tube-type ciliated epithelium surrounded by normal myometrium, consistent with the diagnosis of endosalpingiosis of the uterus (also known as a Müllerian cyst). Currently, there are 18 cases (including ours) in the literature. Of these, two had a uterine malignancy, one endometrioid endometrial carcinoma, and another cervical adenocarcinoma. The age at diagnosis varied from 31 to 73, with a mean of 47 ± 8. The typical clinical manifestations were a palpable low abdominal mass, abnormal menstrual bleeding, and pelvic pain. Overall, 75% (12 of 16) of patients underwent a total hysterectomy, while 62.5% (10 in 16) had a concomitant bilateral salpingo-oophorectomy for nonmalignancy. No recurrence was reported.

CONCLUSION

We describe the youngest patient with tumor-like uterine endosalpingiosis. The preoperative diagnosis is challenging because of its rarity. Most patients had a hysterectomy with castration, which may have resulted in overtreatment. Awareness of this lesion is necessary for the differential diagnosis of uterine and adnexal tumors. Review of relevant literature has shown a relationship between endosalpingiosis progression and cancer development, indicating an uncertain and complicated pathology.

Lineage tracing suggests that ovarian endosalpingiosis does not result from escape of oviductal epithelium

Most high-grade serous carcinomas are thought to arise from Fallopian tube epithelium (FTE), but some likely arise outside of the tube, perhaps from ectopic tubal-type epithelium known as endosalpingiosis. Importantly, the origin of endosalpingiosis is poorly understood. The proximity of the tubal fimbriae to the ovaries has led to the proposal that disruptions in the ovarian surface that occur during ovulation may allow detached FTE to implant in the ovary and form tubal-type glands and cysts. An alternative model suggests that cells present in ectopic locations outside the Müllerian tract retain the capacity for multi-lineage differentiation and can form glands with tubal-type epithelium. We used double transgenic Ovgp1-iCreER^T2 ;R26R^LSL-eYFP mice, which express an eYFP reporter protein in OVGP1-positive tissues following transient tamoxifen (TAM) treatment, to track the fate of oviductal epithelial cells. Cohorts of adult mice were given TAM to activate eYFP expression in oviductal epithelium, and ovaries were examined at time points ranging from 2 days to 12 months post-TAM. To test whether superovulation might increase acquisition of endosalpingiosis, additional cohorts of TAM-treated mice underwent up to five cycles of superovulation and ovaries were examined at 1, 6, and 12 months post-TAM. Ovaries were sectioned in their entirety to identify endosalpingiosis. Immunohistochemical staining for PAX8, tubulin, OVGP1, and eYFP was employed to study endosalpingiosis lesions. Ovarian endosalpingiosis was identified in 14.2% of TAM-treated adult mice. The endosalpingiotic inclusion glands and cysts were lined by secretory and ciliated cells and expressed PAX8, tubulin, OVGP1, and eYFP. Neither age nor superovulation was associated with a significant increase in endosalpingiosis. Endosalpingiosis was also occasionally present in the ovaries of pre-pubertal mice. The findings imply that ovarian endosalpingiosis in the mouse does not likely arise as a consequence of detachment and implantation of tubal epithelium and other mechanisms may be relevant. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Observations on the origin of ovarian cortical inclusion cysts in women undergoing risk-reducing salpingo-oophorectomy

AIMS

Evidence suggests that up to 70% of high-grade serous ovarian carcinomas (HGSCs) arise potentially from fallopian tube fimbriae, and that many of the remaining cases arise from within the ovary in cortical inclusion cysts (CICs) with a Müllerian phenotype (Müllerian-CICs). It has been proposed that Müllerian-CICs arise either from metaplasia of mesothelial ovarian surface epithelium (OSE) entrapped within the ovary after ovulation or from normal tubal cells entrapped postovulation. However, this proposal is controversial. We therefore conducted a study of CICs in women, most of them BRCA1/2 mutation carriers, undergoing risk-reducing salpingo-oophorectomy at our institution from 2000 to 2014.

METHODS AND RESULTS

We used immunohistochemistry for PAX8, a Müllerian marker, and calretinin, a mesothelial marker to classify CIC cells. In 499 CICs from 59 women, 72.3% were positive for PAX8 (PAX8⁺ ): ≥10% of CIC cells positive; 43.5% positive for calretinin (calretinin⁺ ). The proportion of PAX8⁺ CICs increased from 62.9% in premenopausal to 80.5% in postmenopausal patients. The proportion of calretinin⁺ CICs decreased from 52.6% to 35.6%, respectively. There was significant overlap of PAX8 and calretinin positivity: 82 (16.4%) CICs were PAX8⁺ /calretinin⁺ ; 43 (40.2%) of these 82 demonstrated PAX8⁺ /calretinin⁺ in the same cells.

CONCLUSIONS

These results, and the increased ratio of PAX8⁺ to calretinin⁺ CICs from premenopausal to postmenopausal, show that many PAX8⁺ CICs probably arise from metaplasia of OSE-derived CICs. The proportion of PAX⁺ /calretinin^- CICs arising from OSE-derived CICs is unclear, but our results strongly support the proposal that many Müllerian-CICs arise from OSE via metaplasia.

Vaginal Endosalpingiosis Case Report: A Rare Entity Presenting as Intermenstrual Bleeding

Endosalpingiosis is a benign and rare entity whose pathophysiology remains unknown. It has been described in pelvic organs, the abdomen, or axillar lymph nodes. Its underrecognition has occasionally led to its misinterpretation for an adenocarcinoma. This case reports the treatment and follow-up of vaginal endosalpingiosis, presenting as a vaginal polyp in a premenopausal women with intermenstrual bleeding. To our knowledge this is the first reported case of vaginal endosalpingiosis and the second mucosal localization after bladder endosalpingiosis.

Clinicopathological and immunohistochemical analysis of epithelial-lined (true) cysts of the adrenal gland with proposal of a new histogenetic categorization

Epithelial- lined (true) cysts are rare lesions and until now the only information we had about their histogenesis was based on the analysis of a few cases. We retrospectively reviewed 8 cases of cysts with a true epithelial lining (confirmed immunohistochemically). The pathological findings and immunohistochemical analysis of the epithelial linings allowed for categorization of the cysts into 3 groups. Five cysts had pure mesothelial lining, which was flattened to cuboidal, and demonstrated a positive reaction for mesothelial markers (eg. calretinin, WT1), and a negative reaction for EpCAM, EMA, PAX8 and ER. Two cysts had cuboidal to flattened lining, the cells of which were diffusely or focally positive for mesothelial markers, for some epithelial markers (eg. EpCAM and EMA) and despite a lack of müllerian-type epithelium demonstrated a positive reaction for PAX8 and focally for ER. A cyst derived from adreno-hepatic fusion (AHF)-related intra-adrenal bile ductules was diagnosed in a right adrenal gland which was directly adherent to the liver, microscopically features of AHF were visible with intermingling of adrenal and liver parenchymal cells. The immunoreactivity pattern was similar among the preserved cells of the cyst-lining, the intra-adrenal bile ductules and the normal bile ductules in the adjoining liver parenchyma. On the basis of this case series from a single institution (8 presented now and 1 reported before) we propose a new histogenetic categorization of adrenal epithelial cysts into: 1. pure mesothelial cysts (the most common type), 2. mesothelial cysts with incomplete or complete müllerian metaplasia 3. AHF-related cysts.