Mucin-producing urothelial-type adenocarcinoma of prostate: report of two cases of a rare and diagnostically challenging entity

Primary mucinous adenocarcinoma of the urethra: A contemporary clinicopathologic analysis of 17 patients

Mucinous adenocarcinoma of the urethra is rare. Here we performed a contemporary clinicopathologic analysis of this entity in both male and female patients. All cases with secondary tumors involving the urethra were excluded. Clinicopathologic parameters and follow up was obtained. Seventeen patients were included in the study, 9/17 (53 %) male and 8/17 (47 %) female. The mean patient age was 68 years (range: 53-88 years). The majority (11/17, 65 %) of patients were African American, with an even greater incidence (7/8, 87 %) in female patients. In male patients, prostatic urethra was the most common part of the urethra (6/9, 67 %) where the tumor arose from. Immunohistochemical stains were performed in 11/17 (65 %) tumors and were positive for CK20 (11/11, 100 %), CDX2 (11/12, 92 %), CK7 (8/9, 88 %), GATA3 (3/8, 37 %) and negative for NKX3.1, PSA, p63, PAX8, and Beta-Catenin. In resection specimens, tumors were categorized as pT2 (3/11, 27 %), pT3 (1/11, 9 %), and pT4 (7/11, 64 %). Lymph node status was categorized as pN0 (6/9, 67 %), pN1 (1/9, 11 %), and pN2 (2/9, 22 %). Available follow up data showed 7/13 (54 %) patients developed recurrence after surgical resection and chemotherapy, of which 3/7 (43 %) died of widespread metastatic disease. It is critical for pathologists and urologic oncologists to be aware of this entity in both male and female patients in view of potential diagnostic pitfalls, prognosis, and therapeutic implications.

Mucin-producing urothelial-type adenocarcinoma of the prostate with sarcomatoid features and novel molecular phenotype

Introduction

Mucin-producing urothelial-type adenocarcinoma of the prostate is a rare tumor that may not elevate serum prostate-specific antigen, creating significant diagnostic and monitoring challenges. We evaluate our case in detail and review prior studies to demonstrate that the pathologic and molecular features of this tumor are distinct from conventional prostate adenocarcinoma.

Case presentation

Our patient had a remote history of radiation-treated conventional prostate adenocarcinoma and presented many years later with an abscess-like prostate mass leading to urinary obstruction and hematuria. Biopsy revealed mucin-producing urothelial-type adenocarcinoma of the prostate with concurrent sarcomatoid features. Molecular studies showed a unique phenotype involving alterations in the KRAS, PTEN, RAD21, and TP53 genes.

Conclusions

To our knowledge, this is the first report that describes sarcomatoid features and molecular mutations in mucin-producing urothelial-type adenocarcinoma of the prostate.

Mucinous adenocarcinoma of the prostatic urethra after brachytherapy for prostatic adenocarcinoma: a case series

Mucinous adenocarcinoma of the urethra is extremely rare, even more so in a setting of postradiation therapy, with only 3 cases reported up to date including the first case published by our group in 2011. In the present study, we included the long-term follow-up on our previously reported case and report 3 additional cases. This is the first case series to date of this rare disease entity. The aim of this study is to review the clinicopathologic features of mucinous adenocarcinoma of the prostatic urethra in patients after receiving brachytherapy for prostatic adenocarcinoma. We identified 4 patients with a mean age of 72 years, and a mean interval of 14.8 years from brachytherapy for prostate carcinoma (grade group 1). Patients presented with hematuria or urinary retention. A colonoscopy was performed in three-fourth of patients and was within normal limits. Three patients underwent cystoprostatectomy and 1 had a transurethral resection of the prostate. On gross examination, only tumor formed a 3.5 cm tan-gray, ulcerated, friable, and necrotic mass and 2 displayed either irregular red granular or thickened areas within the prostatic urethra. Abundant extracellular mucin pools dissecting the prostatic stroma were present in all tumors, with clusters of tumor cells floating in the mucin. The mucin pools were lined by pleomorphic pseudostratified columnar mucinous epithelium. Tumors were diffusely positive for CK20, CDX2 (4/4), and AMACR (2/2); they focally expressed CK7 (2/4), and lacked nuclear β-catenin expression (3/3). PSA, PSAP, NKX3.1, p63, and GATA3 were negative in the tumors tested. Among the 3 patients who underwent radical surgery, 2 had stage 2 tumors (confined to the prostatic urethra and prostate), and 1 had a stage 3 tumor, with seminal vesicle involvement. All 4 patients were alive without disease with a mean follow-up of 4.9 years. In conclusion, brachytherapy-associated mucinous adenocarcinoma of the prostatic urethra displays intestinal-type features as its non-radiation-related counterpart. It appears to lack a villous adenoma component, displays a different immunohistochemical profile with diffuse CK20 and CDX2 positivity, and is associated with lower stage and less aggressive behavior.

A Rare Case of Co-Existing Mucin-Producing Urothelial-Type Adenocarcinoma of the Prostate and Acinar Adenocarcinoma

Mucin-producing urothelial-type adenocarcinoma of the prostate is an extremely rare neoplasm, and its coexistence with acinar adenocarcinoma is exceptional. A 70-year-old man presented with treatment resistant symptoms of urinary obstruction. The serum prostate specific antigen (PSA) level was normal. Cystoscopy revealed a kind of "cottony fluff" in the prostatic urethra. A computed tomography (CT) scan and magnetic resonance imaging (MRI) showed a polylobulated, hyperintense lesion with mucinous content. It was located in the right lobe of the prostate and measured 35 × 27 × 35 mm. The bladder cavity did not show lesions and the gastrointestinal endoscopy was normal. Thus, the patient underwent a radical cystoprostatectomy. The histological sections showed the characteristics of a mucin-producing adenocarcinoma with extensive areas of mucin pools formation. No areas of necrosis, glandular urethritis, or carcinoma in situ were identified. Neither lymphovascular and perineural invasion nor lymph node metastases were identified. The immunohistochemical study showed diffuse positivity for keratin (KRT) 7, KRT20, and membranous beta-catenin and focal positivity for KRT34betaE12 and caudal-related homeobox gene 2 (CDX2). In addition, we identified a 10-mm focus of prostatic acinar adenocarcinoma that was positive for racemase and NKX3.1. There is no treatment algorithm for this condition; however, surgery (radical prostatectomy) with or without adjuvant chemotherapeutic treatment represents a therapeutic alternative.

Mucin-producing urothelial-type adenocarcinoma of the prostate diagnosed after robot-assisted radical prostatectomy

INTRODUCTION

Mucin-producing adenocarcinoma of the prostate is a rare disease that includes prostate adenocarcinoma with mucus production, secondary adenocarcinoma from the bladder or colorectum, and adenocarcinoma from the urothelium of the prostatic urethra. We describe prostate-specific antigen-negative mucin-producing urothelial-type adenocarcinoma of the prostate.

CASE PRESENTATION

The patient had urinary retention and a serum prostate-specific antigen level of 0.74 ng/mL. Computed tomography and magnetic resonance imaging revealed a prostate tumor with a mucous component. We diagnosed adenocarcinoma by prostate biopsy and subsequently performed robot-assisted radical prostatectomy. Mucin-producing urothelial-type adenocarcinoma of the prostate was diagnosed by pathological examinations. Lung metastasis, developing within 3 months after surgery, was treated using chemotherapy.

CONCLUSION

Endocrine therapy is ineffective for mucin-producing urothelial-type adenocarcinoma of the prostate. Mucin-producing urothelial-type adenocarcinoma of the prostate diagnosis requires pathological and immunohistochemical analyses. It is important to surgically remove the primary lesion, and robot-assisted radical prostatectomy may provide an effective approach. Multimodal therapy is essential to treat for mucin-producing urothelial-type adenocarcinoma of the prostate.

Mucinous adenocarcinoma of the prostatic urethra following a remote history of primary brachytherapy for prostate cancer

Secondary malignancies are a known, albeit uncommon, complication of radiation for prostate cancer, either in the form of external beam radiotherapy or seed-implant brachytherapy. Of these secondary malignancies, mucinous adenocarcinoma of the prostatic urothelium is an extremely rare clinical entity that has only once been reported in the literature. We report the case of an 80-year-old gentleman who initially underwent low-dose brachytherapy for low-risk prostate cancer 18 years ago. He subsequently developed recurrent gross hematuria and obstructive voiding symptoms. He underwent cystoscopy and transurethral resection of a large tumor from within the prostate. Final pathology of the tumor revealed a mucinous adenocarcinoma. Further immunostaining revealed this is likely to have originated from the prostatic urothelium. Given his age, comorbidities, and no clear data demonstrating that aggressive extirpative surgery provides a clinical benefit, we elected to undergo surveillance. Clinicians should be aware of mucinous adenocarcinoma of the prostatic urethra as an extremely rare, radiation-induced malignancy. Once a diagnosis is made, extirpative surgery is an option for localized disease, although prognosis remains poor.

Aggressive course in a patient with mucin-producing urothelial-type adenocarcinoma of the prostate: A case report and review of the literature

Prostate cancer is one of the frequently seen types of cancers in men. The most frequent histological type of prostate cancer is the acinar adenocarcinoma. Mucin-producing urothelial-type adenocarcinoma of the prostate is a very rare subtype. The mucin-producing urothelial-type adenocarcinoma of the prostate has microscopic similarities with colon and bladder adenocarcinoma. It has a more aggressive clinical course and does not respond to androgen deprivation therapy. A 77-year-old male patient diagnosed with mucinous prostate cancer was presented in the current case report.

Mucinous and secondary tumors of the prostate

Primary mucinous tumors and secondary tumors involving the prostate gland are relatively uncommon, however they have important diagnostic, therapeutic, and prognostic implications. The primary mucinous tumors of the prostate include mucinous (colloid) adenocarcinoma of the prostate, prostatic adenocarcinoma with mucinous features, and mucinous adenocarcinoma of the prostatic urethra (mucin-producing urothelial-type adenocarcinoma of the prostate). Mucinous adenocarcinoma of the prostate is defined as a primary prostatic acinar tumor characterized by the presence of at least 25% of the tumor composed of glands with extraluminal mucin. This diagnosis can only be made in radical prostatectomy specimens. Recent studies have shown that these tumors have a similar or in some cases better prognosis than conventional prostatic adenocarcinoma treated by radical prostatectomy. The preferred terminology for tumors that are composed of <25% extraluminal mucinous component in radical prostatectomy specimens is 'prostatic adenocarcinoma with mucinous features.' All cases of prostatic adenocarcinoma with extraluminal mucinous components in prostate needle core biopsies or transurethral resection of the prostate specimens are also referred to as 'prostatic adenocarcinoma with mucinous features.' Mucinous adenocarcinoma of the prostatic urethra (mucin-producing urothelial-type adenocarcinoma of the prostate) as the name implies, does not arise from prostatic acini or ducts, and is a distinct entity that arises from the prostatic urethra usually from urethritis glandularis or glandular metaplasia with malignant transformation, and is analogous to adenocarcinoma with mucinous differentiation arising from the urinary bladder. This tumor is aggressive and has a relatively poor prognosis. The most common secondary tumors that arise from adjacent organs and spread (direct extension or metastasis) to the prostate gland, include urothelial carcinoma of the bladder and colorectal adenocarcinoma. Other secondary tumors that may involve the prostate include metastatic epithelial tumors from several other sites, malignant melanoma and soft tissue tumors.

Co-existence of mucin-producing urothelial-type adenocarcinoma of the prostate and inverted papilloma of the bladder

Adenocarcinoma of prostate with mucinous differentiation arising in the male urethra is extremely rare, with only 21 cases reported in the previous literature. A diagnosis of mucin-producing urothelial carcinoma of the prostate is based on the pathology, immunohistochemistry, and clinical examination by excluding the secondary adenocarcinoma of the prostate. We present a case of unexpected mucinous urothelial carcinoma of prostate with co-existing inverted papilloma of bladder in a 57-year-old man. The patient underwent transurethral resection of the prostate (TURP) and transurethral resection of a bladder tumour (TUR-Bt), and the pathologic result showed mucinous prostate carcinoma and bladder inverted papilloma. Immunohistological stain was negative for prostate-specific antigen (PSA), prostate-specific acid phosphatase (PSAP), and P63, but positive for cytokeratin 7 (CK 7), CK 20, clone 34βE12 and P504S. A complete endoscopic examination was performed to exclude the secondary adenocarcinoma of prostate. This case illustrates the clinical and pathological features of a rare and unexpected mucin-producing urothelial carcinoma of prostate in a bladder neoplasm patient.

Primary mucin-producing urothelial-type adenocarcinoma of the prostatic urethra diagnosed on TURP: a case report and review of literature

BACKGROUND

Mucin-producing urothelial-type adenocarcinoma of the prostatic urethra is extremely rare. These lesions must be differentiated from other mucinous tumors including mucin-producing prostatic adenocarcinoma and metastases from either colonic or bladder primaries.

CASE PRESENTATION

We report here a case of urothelial-type adenocarcinoma arising from the prostatic urethra. The patient is an 81 year-old man with a history of pT1 urothelial cell carcinoma of the bladder status post trans-urethral resection of bladder tumor (TURBT) who initially presented with irritative lower urinary tract symptoms and mucosuria refractory to Flomax and finasteride. A shared decision was made for the patient to undergo trans-urethral resection of prostate (TURP). At the time of surgery, a papillary tumor emanating from the prostatic urethra was found and no urothelial lesions were noted in the bladder. Pathology of the resected prostatic chips revealed an invasive adenocarcinoma with intestinal-type differentiation that stained positive for CK7, CK20, and villin, but negative for PSA, PSAP, uroplakin, and CDX-2. Colonoscopy was normal and CT scan did not show any evidence of colonic lesions nor visceral or lymph node metastases. Thus, the patient was diagnosed with a primary urothelial-type adenocarcinoma of the prostatic urethra.

CONCLUSION

Herein we review the literature regarding this unusual entity, and discuss the differential diagnosis, immunohistochemistry, and the importance of correctly identifying this rare tumor.

A novel subtype of primary prostatic adenocarcinoma: A case report

The present study reports the novel case of an 81-year-old male with prostatic adenocarcinoma (PAC), whose histopathological study revealed a pure urothelial carcinoma (UC) that originated, however, from the prostatic glandular epithelium. The levels of serum prostate-specific antigen (PSA) were extraordinarily high in this patient. An MRI scan indicated a prostatic neoplasm and no malignant changes were observed in the bladder or other areas of the urinary tract. Hematoxylin and eosin-stained sections revealed a diagnosis of pure UC with no other form of differentiation (typical adenocarcinoma or squamous differentiation). The immunohistochemical findings were positive for PSA and P504S, and negative for CK7, CK20, 34βE12 and p63. A diagnosis of primary PAC (solid carcinoma) originating from the prostate was made based on the clinical, histopathological and immunohistochemical observations. This case was susceptible to diagnostic errors, however, a novel subtype of primary PAC was identified and termed the UC-like subtype.

Preneoplasia in the prostate gland with emphasis on high grade prostatic intraepithelial neoplasia

There are a variety of morphological patterns and processes that have been implicated in the pathogenesis of prostate cancer. Prostatic intraepithelial neoplasia (PIN), inflammation with or without atrophy, and adenosis (atypical adenomatous hyperplasia) have all been given candidate status as precursor lesions of prostatic adenocarcinoma. Based on decades of research, high grade prostatic intraepithelial neoplasia (HPIN), a proliferative lesion of prostatic secretory cells, has emerged as the most likely morphological pre-invasive lesion involved in the evolution of many but not all prostatic adenocarcinomas. In this manuscript, we briefly discuss other proposed precursors of prostatic adenocarcinoma and then focus on the history, diagnostic criteria and morphology of HPIN. The incidence of HPIN and its relationship to prostate cancer is reviewed. The differential diagnosis of large glandular patterns in the prostate is discussed in depth. Finally, we summarise the recent clinicopathological studies evaluating the clinical significance of HPIN and discuss follow-up strategies in men diagnosed with HPIN.

Mucin-producing tumors and tumor-like lesions involving the prostate: a comprehensive review

Mucin-producing tumors of the prostate include both primary and secondary tumors with mucinous differentiation or features involving the prostate gland. These tumors are relatively rare and have variable prognostic and therapeutic implications. Primary mucinous (colloid) adenocarcinoma of the prostate is defined as prostatic adenocarcinoma with mucinous differentiation involving 25% or more of the entire tumor. Another primary tumor of the prostate that may have mucinous features is primary mucin-producing urothelial-type adenocarcinoma of the prostate (mucinous prostatic urethral adenocarcinoma). Primary mucin-producing urothelial-type adenocarcinoma of the prostate is a distinct entity that typically arises from the prostatic urethra possibly from urethritis glandularis or glandular metaplasia with malignant transformation, and it is analogous to adenocarcinoma with mucinous differentiation arising from the urinary bladder. Signet ring cell tumors of the prostate, though rare, may also have mucinous features. Secondary tumors with mucinous differentiation that may involve the prostate include adenocarcinomas of the urinary bladder and colorectum. Pathologists should also be aware of mucin-producing tumor-like lesions involving the prostate, including mucinous metaplasia, and benign Cowper glands that may mimic malignancy. Herein we present an updated and comprehensive review of the clinicopathologic, immunohistochemical, molecular, and prognostic features of mucinous tumors and tumor-like lesions involving the prostate gland, with emphasis on mucinous prostatic adenocarcinoma and its mimickers, including potential diagnostic pitfalls.

Mucin-producing urothelial-type adenocarcinoma of the prostate as a mimicker of colonic adenocarcinoma: a case report and review of the literature

A 59-year-old man presented with persistent urinary obstructive symptoms, gross hematuria, and mucusuria. Subsequently, a prostate-specific antigen (PSA)-negative mucin-producing urothelial type adenocarcinoma of prostate was found. The serum PSA level was within the normal limit. Colonoscopy, positron emission tomography, and other tumor surveys showed this to be the only prostate lesion. Microscopically, there was an adenocarcinoma with copious mucin production, with the formation of mucin pools. The neoplastic glands were variously arranged in cribriform, glandular, and villous adenoma-like patterns. This is a very rare tumor, of which there are only 20 cases reported in the literature in the English language. It is critical to distinguish it from mucinous acinar adenocarcinoma of the prostate and from metastatic adenocarcinoma of either the bladder or colon. This is mainly because mucin-producing urothelial type adenocarcinoma of the prostate has a different clinical behavior, and hence, the treatment plan is different from that for conventional prostatic adenocarcinoma. Specifically, it has a more aggressive clinical course and is unresponsive to hormone therapy.

Primary mucin-producing urothelial-type adenocarcinoma of prostate: report of 15 cases

Prostatic urothelial-type adenocarcinoma arises through a process of glandular metaplasia of the prostatic urethral urothelium and subsequent in situ adenocarcinoma sometimes associated with villous adenoma. These prostatic adenocarcinomas are analogous to nonurachal adenocarcinomas arising in the bladder from cystitis glandularis. Only 2 cases of urothelial-type adenocarcinoma from an institution other than our own have been previously described. The distinction between adenocarcinoma from another organ secondarily involving the prostate, usual adenocarcinoma of the prostate, and prostatic urothelial-type adenocarcinoma can present a significant diagnostic challenge and has significant therapeutic implications. Fifteen cases of prostatic urothelial-type adenocarcinoma were retrieved from the consult files of one of the authors. Mean patient age at diagnosis was 72 years (range 58 to 93 y). All men had negative colonoscopies, clinically excluding a colonic primary. Bladder primaries were ruled out clinically or pathologically in radical resection specimens. Follow-up was available on all men with a mean of 50.3 months (range 2 to 161 mo). All men presented with urinary obstruction symptoms with 3 (20%) also having mucusuria and 2 (13.3%) also having hematuria. Four men (26.7%) developed metastatic disease and 8 (53.3%) died of disease. In 8/15 (53%) cases, glandular metaplasia of the prostatic urethra and contiguous transition to adenocarcinoma were identified. Multiple histologic patterns were observed including dissection of the stroma by mucin pools 15/15 (100%), villous features 7/15 (47%), necrosis 2/15 (13.3%), signet ring cells 3/15 (20%), perineural invasion 1/15 (6.7%), focal squamous differentiation 1/15 (6.7%), and a granulomatous inflammatory response 1/15 (6.7%). Immunohistochemical stains were negative for prostate specific antigen, prostate specific acid phosphatase, CDX2, and beta-catenin in all cases. Stains were positive for high molecular weight cytokeratin in 12/12 cases (100%), and CK7 and CK20 in 10/12 cases (83.3%). Prostatic urothelial-type adenocarcinoma is a rare aggressive cancer arising in the prostate. The differential diagnosis includes conventional prostatic mucinous adenocarcinoma and secondary infiltration from a colonic or bladder adenocarcinoma. Immunohistochemistry for prostate specific antigen, prostate specific acid phosphatase, and high molecular weight cytokeratin along with morphology can help rule out conventional prostate carcinoma. beta-catenin, CDX2, and clinical studies are needed to rule out colonic adenocarcinoma. As prostatic urothelial-type adenocarcinoma is entirely analogous to bladder adenocarcinoma in both, its morphology and immunophenotype, only clinical studies or in some cases pathologic examination of the cystoprostatectomy specimen can exclude infiltration from a primary bladder adenocarcinoma.

Mechanisms of Disease: high-grade prostatic intraepithelial neoplasia and other proposed preneoplastic lesions in the prostate

High-grade prostatic intraepithelial neoplasia (HGPIN) is the most likely precursor of prostatic adenocarcinoma according to virtually all available evidence. This lesion is characterized by cellular proliferations within pre-existing ducts and acini, with nuclear and nucleolar enlargements similar to those seen in prostate cancer, although unlike cancer HGPIN retains a basal-cell layer. The recognition of HGPIN is clinically important because of the strong association between this disease and prostatic carcinoma. The predictive value for cancer of an initial diagnosis of HGPIN on needle biopsy has substantially declined, with values falling from 36% to 21%. A major factor contributing to this decline is related to increased use of needle biopsy core sampling, which has provided the means for many cancers associated with HGPIN to be detected on initial biopsy; repeat biopsy, even with good sampling, does not detect many additional cancers. Other possible findings in the prostate might indicate premalignant disease (low-grade prostatic intraepithelial neoplasia, atrophy, malignancy-associated changes, and atypical adenomatous hyperplasia or adenosis), but the data for these premalignant diseases are much less convincing than those for HGPIN.

Morphological markers of secretory activity in prostatic adenocarcinoma

Background/Aim. The vast majority of prostatic tumors developing in adult males are adenocarcinomas (ACP). Histological diagnosis of prostate cancer relies on the infiltrative growth pattern, presence of macronucleoli, and absence of basal cell layer. In the last few years a special attention has been focused on investigation of cancerous glands lumen content. The aim of the study was to determine the presence of intraluminal (crystaloids, blue-tanged mucinous secretions and distension of glands) and extracellular markers of pathological secretions in ACP, as well as the type of intraluminal and extracellular mucinous secretions. Methods. Micromorphological and hystochemical (PAS, HIDAB pH 2.5) analysis was done in 96 patients to detemine differentiation by Gleason and markers of secretory activity. Results. In ACP neoplastic gland`s distension (53.12%), crystalloids (30.2%), basophilic secretions (26.04%) and presence of extracellular mucins (8.3%) were found. All morphological signs were detected in carcinoma of Gleason grade 1-4A. There was significant presence of crystalloids ((G1+G2)/G4 p < 0.05; G3/G4A p < 0.05), basophilic secretions (G3/G2 p < 0.05; G3/G4A p < 0.05) and extracellular mucins (G3/G4A p < 0.001). The association of these morphological features with neutral and acidic mucins secretion was statisticaly significant (p < 0.0001). Conclusion. This study showed that intraluminal and extracellular markers of secretory activity in ACP were significantly more often associated by mixed type of mucin secretion with predominace of sialomucins. .

Urothelial-Type adenocarcinoma of the prostate mimicking metastatic colorectal adenocarcinoma

Adenocarcinoma arising in urinary bladder or prostatic urethra is uncommon. When they occur, the tumor can be mistaken for metastatic lesions, especially from the colon. Here we report the fifth case of a primary urothelial-type adenocarcinoma arising in the prostate which showed enteric differentiation. The patient was a 55 year-old male whose prostatic needle core biopsy showed a high grade adenocarcinoma which was initially thought to be metastatic colon cancer. A follow-up colonoscopy was unremarkable. Subsequent prostatectomy revealed a high grade adenocarcinoma which was positive for cytokeratins 7 and 20, carcinoembryonic antigen, CDX2, and high molecular weight cytokeratin, and negative for prostate specific antigen, prostate specific acid phosphatase and AMACR. A diagnosis of urothelial-type adenocarcinoma of the prostate was rendered. We review the literature regarding this entity, and discuss the differential diagnosis, emphasizing utility of immunohistochemistry in making the diagnosis. Finally, we speculate on the behavior of these rare tumors.