Malakoplakia of the Endometrium: A Rare Unexpected Disease Raising Clinical Concern for Malignancy

Malakoplakia is a rare disease that manifests as a histiocytic inflammatory process and most often occurs in the urinary bladder. It is caused by an impaired capacity of histiocytes to kill and digest bacteria. The typical histopathologic findings are sheets of histiocytes with granular eosinophilic cytoplasm and characteristic Michaelis-Gutmann bodies, spherical bodies with a targetoid appearance. Malakoplakia is even rarer in the gynecologic tract, and our literature search found only 21 published patients of malakoplakia involving the endometrium. Here we report a 60-year-old female patient who presented with recurrent pelvic infections and postmenopausal bleeding, which raised concern for an endometrial malignancy. Hysterectomy with salpingo-oophorectomy revealed malakoplakia involving the endometrium and also the right ovary. Michaelis-Gutmann bodies were visible on the intraoperative frozen section that was performed to rule out an endometrial malignancy. We summarize the clinicopathologic findings of the published patients of endometrial malakoplakia.

Severe Ulcerative Colitis Complicated by Malakoplakia Resulting in Proctocolectomy

We report a 45-year-old man with medically refractory ulcerative colitis with superimposed colonic malakoplakia, presumed related to chronic use of azathioprine and biologics. This is the first reported case of malakoplakia in a patient requiring high doses of combination therapy. Treatment of malakoplakia is not standardized, but can involve systemic antibiotics, or surgical resection, which in this case resulted in proctocolectomy.

Malakoplakia of the small intestine presenting as an abdominal mass

Malakoplakia is a rare chronic granulomatous disease that typically involves the urinary and gastrointestinal tracts of immunocompromised individuals. Characteristic histologic features include von Hansemann cells and Michaelis-Gutmann bodies. Clinical manifestations, based on the organ system effected, range from cutaneous lesions, irritative urinary symptoms, and hematochezia. We report a rare example of malakoplakia presenting as an abdominal mass with extensive intestinal and pelvic involvement complicated by a superficial polymicrobial abscess. This case report aims to describe the proposed pathogenesis, variable clinical presentation, and surgical management of malakoplakia.

Cutaneous malakoplakia arising on the ankle of a patient with pyoderma gangrenosum

Malakoplakia is a rare chronic inflammatory condition that most commonly involves the urogenital tract. Cutaneous malakoplakia is extremely rare and many patients diagnosed with skin involvement are immunosuppressed. While the clinical presentation of cutaneous malakoplakia is variable, the histopathologic features are quite distinct and include sheets of closely packed dermal histiocytes with foamy-appearing cytoplasm and Michaelis-Gutmann bodies that are positive with certain immunohistochemical stains. While the exact pathogenesis of malakoplakia is unknown, it has been associated with certain bacterial infections. Treatment generally involves a combination of surgery and antimicrobial agents and/or modulation of immunosuppressant therapy if appropriate. Herein, the authors report a unique case of cutaneous malakoplakia arising in a patient on chronic immunosuppressive therapy for the management of pyoderma gangrenosum.

A Case of Urinary Bladder Malakoplakia in a Young French Bulldog: Diagnostic and Therapeutic Issues

A 3-month-old female French Bulldog presented with hematuria, severe pollakiuria, and urinary incontinence lasting for 1.5 months. Broad-spectrum empirical antibiotic therapy and nonsteroidal anti-inflammatory drugs were initiated by the referring veterinarian. Due to a lack of improvement, the dog was referred. At referral examination, urinary clinical signs persisted (hematuria, severe pollakiuria) and a firm bladder was noted. Abdominal ultrasonography revealed severe, diffuse bladder wall thickening with a significant reduction in the bladder lumen. Urinary tract endoscopy showed whitish exophytic proliferations throughout the entire bladder wall. Histological bladder wall analysis led to a diagnosis of bladder malakoplakia. Prolonged antibiotic therapy with fluoroquinolones was prescribed and resulted in clinical remission despite persistent bacteria in the bladder wall. This report describes a case of successfully medically managed bladder malakoplakia, a very rare condition in veterinary medicine, well documented in humans.

Multiple-Organ Involvement of Malakoplakia Mimicking Malignant Neoplasms on 18 F-FDG PET/CT

ABSTRACT

Abdominal contrast-enhanced CT was performed in a 61-year-old man with difficulties of urination and defecation for 4 months, which revealed huge rectal masses involving multiple adjacent organs, suspected as malignant lesions. 18 F-FDG PET/CT was subsequently performed for staging. The images showed intense FDG uptake and slightly hyperdense masses involving rectum, bladder, prostate, left ureter, and the anterior abdominal wall at the level of the pelvic cavity. Histopathological examination confirmed the masses were due to malakoplakia, which displayed as abundant von Hansemann cells aggregated and infiltrated in lesions, with distinctive cytoplasmic inclusions termed Michaelis-Gutmann bodies.

A case of canine intestinal malakoplakia

Malakoplakia is a rare chronic granulomatous disease usually affecting the urinary bladder and other locations. In humans, the gastrointestinal tract is the second most common location but there are no reports of intestinal malakoplakia in animals. A 10-month-old female French Bulldog was presented with chronic haemorrhagic diarrhoea and anorexia with normochromic-normocytic anaemia and hypoalbuminaemia. Grossly, there was mucosal thickening and ulceration of the caecum, colon and rectum. Microscopically, transmural sheets of foamy macrophages were seen in these tissues. Macrophages were periodic acid-Schiff, vimentin and ionized calcium-binding adaptor molecule 1 positive and contained von Kossa- and Prussian blue-positive Michaelis-Gutmann bodies. Giemsa staining revealed rod-shaped bacterial colonies and fluorescence in-situ hybridization demonstrated Escherichia coli within macrophages. This is the first reported case of intestinal malakoplakia in domestic animals. Pathological features of intestinal malakoplakia share many similarities with ulcerative histiocytic colitis in dogs but it is unclear if they are different forms of the same pathological process or distinct entities.

Malakoplakia of the Gallbladder: A Case Report

Histiocytes are cells that are involved in the immune responses of the body. They are unable to properly break down the bacterial material in malakoplakia, a chronic granulomatous histiocytic disease that occurs in immunocompromised patients and autoimmune conditions. Very few reports of these lesions exist, as those that occur in the gallbladder. It typically affects the urinary bladder, alimentary tract, cutaneous, hepato-biliary, and male and female genital systems. These lesions are usually incidental findings that result in patients being misdiagnosed. A 70-year-old female presented with right lower quadrant abdominal pain, and malakoplakia of the gallbladder was diagnosed. Histopathology findings revealed malakoplakia of the gallbladder, and the same was confirmed with special stains such as periodic acid-Schiff (PAS). This case highlights the role of gross and histopathology findings as a clue to the diagnosis, which helps the surgeon with further management.

Pancreatic Malakoplakia: A Rare Pathology Associated With Acute Pancreatitis

Malakoplakia is a rare granulomatous tumor-like inflammatory condition, most frequently involving the genitourinary system and occurring in immunosuppressed patients. The gastrointestinal tract is the second most common site, where it is usually seen involving the colon. We report a case of malakoplakia presenting as a pancreatic mass. Imaging showed soft tissue along the pancreatic tail/greater curvature concerning for infiltrating tumor, but endoscopic ultrasound with biopsy showed malakoplakia. Our case discusses malakoplakia at an uncommon site, which was appropriately treated with antibiotics.

Successful treatment of malakoplakia of the liver and skin in a pediatric liver transplant patient

BACKGROUND

Malakoplakia occurs uncommonly at any age, but pediatric reports are exceptionally limited. Malakoplakia appears primarily in the urinary tract, although involvement of essentially all organs has been reported, cutaneous malakoplakia is very uncommon and liver involvement is the rarest.

METHOD

We report the first pediatric case of concurrent hepatic and cutaneous malakoplakia in a pediatric liver transplant recipient. We also provide a literature review for cutaneous malakoplakia cases in children.

RESULT

A 16-year-old male received a deceased-donor liver transplant for autoimmune hepatitis, present with the persistence of the liver mass of unknown etiology and cutaneous plaque-like lesions around the surgical scar. Core biopsies taken from the skin and abdominal wall lesions demonstrated histiocytes containing Michaelis-Gutmann bodies (MGB) revealing the diagnosis. The patient successfully was treated with antibiotics alone for 9 months without surgical intervention or a decrease in immunosuppressive therapy.

CONCLUSION

This case demonstrates the need to include malakoplakia in the differential diagnosis of mass-forming lesions after solid transplantation and increase awareness of this very rare entity in pediatrics.

A Surgical Challenge Generated by Colonic Malakoplakia in Disguise as a Locally Advanced Colonic Malignancy-A Case Report

Colonic malakoplakia is an uncommon granulomatous development of cells resulting from the impaired capacity of the mononuclear cells to eliminate the phagocytosed bacteria, and in rare cases it can also affect the gastrointestinal tract. We report the case of a 78-year-old female patient that was admitted to hospital by The Emergency Department with the diagnosis of bowel obstruction, confirmed by the clinical and paraclinical investigations. We decided to surgically manage the case for suspicious symptomatic colonic neoplasm. The histological examination of the surgical specimens revealed colonic malakoplakia, characterized by the presence of the aggregated granular histiocytes and Michaelis-Gutmann bodies. Through this paper, we want to raise awareness for Malakoplakia, which remains an extremely rare disease that may affect multiple organs, and because it does not present specific symptoms or clinical manifestations, the final diagnosis remains the histopathological study. The clinical conduct should be decided after taking into consideration all the aspects of this pathology along with the benefits and risks for the patient.

Xanthogranulomatous Pyelonephritis and Its Differential Diagnoses: An In-Depth Case Review

Xanthogranulomatous pyelonephritis is a rare chronic infectious process of the kidney, which has been described in three different forms: diffuse, segmental, and focal. It is also known as the great simulator since its clinical, radiological, and histopathological manifestations tend to be confused with other entities. We describe a case of a 55-year-old male patient with two months of clinical manifestations characterized by a 7x7-cm palpable mass in his right lumbar region, which was hot and painful upon touch and increasing in size. This article aims to present a case of xanthogranulomatous pyelonephritis and compare it with its primary differential diagnoses. It is evident that despite the condition being considered a simulating pathology, some key differences can be found to identify and distinguish it.

Malakoplakia and xanthogranulomatous pyelonephritis treated with nephrectomy: A case report

RATIONALE

Malakoplakia and xanthogranulomatous pyelonephritis are chronic inflammatory conditions of the kidney characterized by the infiltration of inflammatory cells.

PATIENT CONCERNS

An 82-year-old female patient had a history of hypertension, type 2 diabetes mellitus, dyslipidemia, and end-stage renal disease under hemodialysis. She was admitted repeatedly 4 times within 4 months due to urosepsis.

DIAGNOSIS

The enlarged right kidney with a low-density lesion at the right middle calyx, and a well-enhanced ureter were noted on the computed tomography scan. Therefore, xanthogranulomatous inflammation was suspected. Semi-rigid ureteroscopy with biopsy was performed, and xanthogranulomatous inflammation of the ureter was confirmed on the pathology report.

INTERVENTIONS

After right open radical nephrectomy was performed, the final pathology report revealed malakoplakia with xanthogranulomatous pyelonephritis.

OUTCOMES

After the surgery, she has no longer suffered from urosepsis for 8 months, and there were no adverse event or recurrence noted.

LESSONS

With this case report, we aim to emphasize that these 2 diseases are not mutually exclusive, but they may exist simultaneously in the same patient.

Malakoplakia in the Urinary Bladder of 4 Puppies

Malakoplakia in humans most often affects the urinary bladder and is characterized by inflammation with von Hansemann-type macrophages, with or without Michaelis-Gutmann bodies, and is frequently associated with Escherichia coli infection. We describe the microscopic features of malakoplakia in the urinary bladder of 4 puppies. In all cases, the lamina propria of the urinary bladder was markedly expanded by sheets of large, round to polygonal macrophages with intracytoplasmic, periodic acid-Schiff-positive granules and granular inclusions, and rare Prussian blue-positive inclusions. Macrophages were positive for CD18 and Iba1. In 2 cases, Michaelis-Gutmann bodies were detected with hematoxylin and eosin stain and were best demonstrated with von Kossa stain. E. coli infection was confirmed in 2 cases with bacterial culture or polymerase chain reaction (PCR) and sequencing of the bacterial 16S ribosomal RNA gene. Transmission electron microscopy of one case demonstrated macrophages with abundant lysosomes, phagolysosomes, and rod-shaped bacteria. Microscopic features were similar to human cases of malakoplakia. In dogs, the light microscopic characteristics of malakoplakia closely resemble granular cell tumors and histiocytic ulcerative colitis.

Exuberant Malakoplakia of the Prostate Presenting as Prostatic Abscesses in an Immunocompromised Patient

Background: Malakoplakia is a rare benign lesion, usually associated with deficient intralysosomal degradation of microorganisms, more commonly, Escherichia coli. Malakoplakia occurs in various organ systems, the most frequently affected site being the urinary bladder. We report a rare case of isolated extensive malakoplakia involving the prostate, diagnosed on transurethral resection performed for radiologically suspected prostatic abscesses. Case Presentation: A 61-year-old African American male presented with symptoms of urinary obstruction for the past 2 months. His medical history was significant for immunosuppression (liver transplantation 3 months prior and diabetes mellitus). He reported four episodes of E. coli-associated urinary tract infection after his liver transplantation. Serum prostate specific antigen was 1.83 ng/cc (normal inferior to 4 ng/cc), and urine culture was positive for E. coli sensitive to ceftriaxone. Pelvic magnetic resonance imaging was suggestive of prostatitis with prostatic abscesses; cystoscopy was unremarkable. The patient was started on intravenous ceftriaxone therapy. A standard bipolar transurethral resection of the prostate was performed, and purulent-like material was encountered in the resected tissue. Histologic examination demonstrated extensive infiltration and replacement of the prostatic tissue by sheets of pink histiocytes with targetoid inclusions consistent with Michaelis-Gutmann bodies, ultimately confirming malakoplakia of the prostate. Conclusion: Prostatic malakoplakia is an unexpected diagnosis in patients suspected of having malignancy or prostatitis. Its exact pathogenesis is unknown, but it involves defective bacterial degradation after phagocytosis. E. coli is often cultured from the patients' urine. Immunosuppression, present in our patient, is a well-known associated factor. Prostatic malakoplakia can radiologically masquerade as prostatic adenocarcinoma, despite the use of cutting-edge imaging technology. With the growing use of multiparametric 3T prostate magnetic resonance imaging to screen for prostate cancer, it is possible that urologists, radiologists, and pathologists will encounter prostatic malakoplakia more frequently in the future.

Malakoplakia, a malignant mimic

Malakoplakia is a chronic inflammatory condition that affects multiple systems, most commonly the urogenital tract. Its clinical presentation is often non-specific, but is typically characterized by recurrent urinary tract infections and haematuria. We report a rare case of intravesical malakoplakia mimicking an aggressive transitional cell carcinoma both in its clinical presentation and in its macroscopic appearance on cystoscopy in an 82-year patient, the oldest reported case in the literature. Malakoplakia has been described in the literature as a benign disease process presenting typically in younger patients. This case demonstrates its ability to cause obstructive uropathy and affect elderly patients. Thus, this case serves as a reminder to consider malakoplakia as a differential in the evaluation of suspected bladder malignancy in patients of all ages.

Rectal malakoplakia

Malakoplakia is a rare chronic granulomatous disease with potential to affect multiple organs. Gastrointestinal involvement is considered one of the most common locations outside of the urinary tract. Herein, we present the case of a man who presented to our clinic with painless hematochezia. Physical examination findings were unremarkable; however, colonoscopy revealed a frond-like/villous, fungating, and polypoid nonobstructing circumferential mass in the rectum. Histopathological examination of the lesion revealed findings consistent with malakoplakia.

Appendiceal malakoplakia masquerading as a cecal mass

Appendiceal malakoplakia masquerading as a cecal mass is uniquely rare. The presence of an infiltrate of granular eosinophilic macrophages containing Michaelis–Gutmann bodies on histopathology is pathognomonic of malakoplakia. Cutaneous, gastrointestinal and most commonly urogenital malakoplakia is reported in association with an immunocompromised state, infectious, inflammatory and neoplastic processes. Presentation varies from microscopic disease to plaques, nodules, polypoid lesions and small masses. However, a cecal mass postea proven appendiceal malakoplakia deserves special attention. We could not find similar case reports in the English literature. The pathogenesis of malakoplakia is poorly understood, and it is unclear if it is a harbinger of malignancy, a precursor lesion or an inflammatory marker. In the setting of a dominant appendiceal mass, post-treatment endoscopic and tumor marker surveillance is paramount but, however, undefined in contemporary literature.

Renal malakoplakia mimicking a malignancy and diagnosed by fine-needle aspiration: A case report

Malakoplakia is a rare, granulomatous disease that affects a wide variety of organs and can have a clinical and radiographic presentation resembling that of malignancy. The genitourinary tract is the most commonly involved site. There are scant reported cases presenting as a locally advanced renal mass and even rarer, diagnosed by fine-needle aspiration (FNA) cytology. We report clinical, imaging, cytologic, and histological findings of an interesting case of malakoplakia initially diagnosed by FNA cytology. We also briefly review the literature and emphasize the importance of recognizing this entity when encountered in an aspirate material, which can help mitigate the diagnostic confusion of malakoplakia for clinicians.

von Hansemann Cells from Fresh Urine Sediment Samples in the Diagnosis of Malakoplakia

Background

Malakoplakia is characterized by the presence of plaques with macrophages containing inclusion bodies. The diagnosis of this disease is carried out by biopsy of the lesion. The objective of this paper was to assess the value of fresh urine sediment in the diagnosis of malakoplakia.

Materials and Methods

Five suspected cases of malakoplakia that showed macrophages with inclusions called bodies of Michaelis-Gutmann (von Hansemann cells) in unstained urine sediment were processed with Papanicolaou, Giemsa, and periodic acid-Schiff (PAS) stains. Four of the five patients had a history of cystitis and had developed antibiotic resistance. The other patient had the characteristics cells in a routine urinalysis.

Results

Papanicolaou stain revealed intracytoplasmic eosinophilic or basophilic bodies, single or multiple in macrophages. Such bodies were stained deep red with PAS technique. Giemsa stain showed these bodies with a faint basophilic coloration, sometimes with a central core. Bladder biopsies established the definitive diagnosis, showing bodies within and outside macrophages, with a concentric "birds-eye" or "owl-eye" (targetoid) appearance.

Conclusions

Finding of von Hansemann cells in fresh urine sediment of patients with cystitis and a history of resistance to antibiotic scan leads to the diagnosis of malakoplakia. Giemsa stain can show in some cases the characteristic central core of Michaelis-Gutmann bodies. Malakoplakia is probably the result of an acquired defect in macrophage function causing impairment of bactericidal activity. A correct diagnosis is important because the spread to ureters with bilateral stenosis and obstruction can lead to kidney failure.

Malakoplakia of the urinary system

Malakoplakia is regarded as a chronic granulomatous inflammatory disease with a good prognosis. It usually affects the urinary system, especially the urinary bladder. Bacterial infections, including E. coli are thought to be the main factor in pathogenesis. It frequently coexists with chronic diseases and immunosuppression state. Histopathological examination of affected tissue samples is thought to be the best diagnostic method. The basic microscopic feature is mixed inflammatory infiltration containing foamy histiocytes known as von Hansemann cells, frequently with basophilic inclusions known as Michaelis-Gutmann bodies. Symptoms and the clinical course of malakoplakia depend on location and the extent of the lesions. The lesion is treated successfully with antibiotic therapy and surgical excision.

Malakoplakia as a cause of severe hypercalcemia through ectopic 25-hydroxyvitamin D3 1-alpha-hydroxylase expression: A case report

RATIONALE

Malakoplakia is a rare disease characterized by the presence of nongranulomatous macrophage infiltration. In most cases, it affects the urinary tract. Malakoplakia can cause acute kidney injury when it is localized in the kidneys.

PATIENT CONCERNS

Here, we report the case of a 65-year-old female patient with renal malakoplakia responsible for hypercalcemia. During her initial assessment, she was also diagnosed 25-OH vitamin D insufficiency, for which she was prescribed oral cholecalciferol. Three months later, she developed severe hypercalcemia with normal 25-OH vitamin D and parathyroid hormone levels and high 1,25-dihydroxyvitamin D levels.

DIAGNOSES

After a superimposed granulomatous disease was excluded, malakoplakia cells were suspected to be responsible for the abnormal 25-hydroxyvitamin D3 1-alpha-hydroxylase activity, which was confirmed by immunohistochemistry.

INTERVENTIONS

Cholecalciferol was stopped, the patient was rehydrated with intravenous physiological saline, and prednisone was initiated to decrease the enzyme activity.

OUTCOMES

Six months later, she displayed normal serum calcium, 25-OH vitamin D and 1,25-dihydroxyvitamin D levels.

LESSONS

This case illustrates that malakoplakia may exhibit ectopic 25-hydroxyvitamin D3 1-alpha-hydroxylase activity and cause severe hypercalcemia upon vitamin D supplementation. Therefore, such supplementation should not be given in malakoplakia patients without an actual deficiency and requires careful monitoring of serum calcium.

Bladder Malakoplakia in Systemic Sclerosis Patient: A Case Report and Review Literature

Malakoplakia, an anecdotal reactive granulomatous lesion, is a rare pathologic entity but relatively more common in genitourinary tracts. Here we report a case of malakoplakia in the urinary bladder in systemic sclerosis. The patient was a 66-year-old female treated with long-term corticosteroid and cyclophosphamide. She presented with gross hematuria, and cystoscopy and biopsy revealed malakoplakia. There was no tumor and the stains for infectious organism were all negative. To the best of our knowledge, this is the first case report of malakoplakia in a systemic sclerosis patient.

An Unusual Association of Renal Cell Carcinoma and Renal Malakoplakia with Focal Segmental Glomerulosclerosis in an Elderly Patient

The association of malignancy and glomerulonephritis may be missed, especially in elderly patients. Here, we report a case of eosinophilic variant of renal cell carcinoma and renal parenchymal malakoplakia discovered on renal biopsy in a patient with steroid-dependent nephrotic syndrome. The presence of malakoplakia in our biopsy was probably due to systemic steroid therapy for glomerulonephritis, presence of concomitant asymptomatic urinary tract infection, and/or history of diabetes mellitus. The patient had remission of proteinuria following laparoscopic removal of the tumor, indicating probable remission of glomerulonephritis.

Malakoplakia after kidney transplantation: Case report and literature review

Malakoplakia is a granulomatous disease associated with an infectious etiology, usually involving the urinary tract. It reveals itself as a recurrent urinary tract infection (r-UTI), and in some cases, it is associated with impairment of renal function. Immunosuppression is one of its main associated factors, and it has been increasingly described in patients with solid organ transplantation (SOT), mainly kidney transplantation. Macroscopically, it can form masses and sometimes it may be confused with neoplasia, which is why histological findings are fundamental for the diagnosis. Here, we present a case of bladder malakoplakia, manifested by r-UTI from Escherichia coli in a patient with renal transplantation, refractory to long-term antibiotic treatment and reduction in immunosuppression, which resolved after surgical management. We also summarize the clinical characteristics of malakoplakia and compare them with previous reports in the literature on SOT.

Malakoplakia of the Prostate as a Mimicker of Prostate Cancer on Prostate Health Index and Magnetic Resonance Imaging-Fusion Prostate Biopsy: A Case Report

Background: Isolated malakoplakia of the prostate is a rare inflammatory condition that has been clinically mistaken for prostatic malignancies. The development of Prostate Imaging Reporting and Data System (PI-RADS) classifications, and Prostate Health Index (PHI) has led to more accurate diagnosis of clinically significant disease and stratification of patients that may be at risk of prostate cancer.

Case Presentation: We present a case of a 75-year-old male who was on follow-up with our hospital for elevated prostate specific antigen (PSA). He was admitted for an episode of urosepsis, which was treated with antibiotics and subsequently underwent further workup and was found to have a raised PHI, as well as a high PI-RADS classification and was later found to have malakoplakia based on histology of prostate tissue obtained during targeted magnetic resonance imaging (MRI)-guided fusion prostate biopsy.

Conclusion: To our understanding, this is the first case where a prostate lesion has been labeled as a PI-RADS 5 lesion, with elevated PHI that has subsequently been proven histologically to be malakoplakia. An important possible confounder is the interval between the MRI and the episode of urosepsis and it is well known that urosepsis can affect the PSA and MRI result. We present this case to highlight the potential for a false diagnosis of prostate cancer, in spite of laboratory and radiological findings.

Co-existing malakoplakia and xanthogranulomatous pyelonephritis of kidney: Two different spectrum of same disease process

Xanthogranulomatous pyelonephritis (XGP) and malakoplakia (MKP) are chronic inflammatory condition of kidney characterized by infiltration of inflammatory cells. We are presenting a rare case of concomitant XGP and MKP in the same kidney. This signifies that the two are different spectrums of the same disease process.

Malakoplakia Associated With Multiple Adenomas of the Colon: An Extremely Rare Incidental Finding

Malakoplakia in the colon has been described either as part of a systemic disease with a diffuse presentation or as a rare incidental finding associated usually with an adenocarcinoma. To our knowledge, the association of malakoplakia with colonic adenoma is very rare and only 5 cases, including the present case, have been reported so far. Here, we describe a case of malakoplakia coexisting with multiple sigmoid colonic adenomas in a 67-year-old patient without any underlying inflammatory or infectious disease and with no history of immunosuppressive treatment. As far as we are concerned, this is the first description of malakoplakia associated with multiple colonic adenomas.

A 13-Month-Old With Xanthogranulomatous Pyelonephritis With Features of Renal Malakoplakia

Xanthogranulomatous pyelonephritis is an uncommon chronic inflammatory renal disorder caused by chronic infection with gram-negative bacteria leading to destruction of the renal parenchyma and replacement with foamy lipid-laden macrophages. Renal malakoplakia is another rare form of chronic inflammatory granulomatous disease in the kidney associated with infection usually occurring in adults with immunocompromised status or debilitating disease. It is hallmarked by the finding of foamy histiocytes with distinctive basophilic inclusions (Michaelis-Gutmann bodies). We present a case of a 13-month-old male with history of congenital hydronephrosis who presented with clinical and radiologic findings suggestive of xanthogranulomatous pyelonephritis. However, further pathologic studies revealed the presence of Michaelis-Gutmann bodies, which are pathognomonic for renal malakoplakia. With this case we hope to bring further evidence to support that these two conditions are not mutually exclusive but rather represent two pathologic processes on the same disease spectrum.

Disseminated Mycobacterium Simiae with Pelvic Malakoplakia in an AIDS Patient

Malakoplakia in an acquired immunodeficiency syndrome (AIDS) patient with disseminated Mycobacterium simiae infection presented with a large pelvic mass that caused organ dysfunction from mimicking a tumor. Malakoplakia is a rare, chronic granulomatous abnormal host response toward infectious agents, presenting as a tumor-like lesion. This is the first report of pelvic malakoplakia after disseminated M. simiae infection in an AIDS patient.

Coexistence of Malakoplakia and Papillary Urothelial Carcinoma of the Urinary Bladder

Malakoplakia is a rare granulomatous disease that commonly involves the genitourinary tract, with the urinary bladder being the most frequently affected site. Grossly, malakoplakia can present as soft yellow plaques, nodules, bladder mass, or even without any visible lesion. In this article, we present a 74-year-old female with a background of hypertension, hyperlipidemia, and poorly controlled diabetes who presented with sepsis of unknown origin. During the course of the investigation of the source of her sepsis, an incidental bladder tumor was discovered. She subsequently underwent transurethral resection of the bladder tumor. Histology revealed ordinary low-grade papillary urothelial carcinoma that had small colonies of malakoplakia that appeared to have developed secondary to the tumor and presented concurrently. We seek to demonstrate the rare association of papillary urothelial carcinoma and malakoplakia.

Testicular malakoplakia: a rare sonographic mimic of malignancy

Testicular malakoplakia is a rare, benign condition that most often occurs in an immunocompromised patient with chronic infection. Its occurrence is acute, with pain and testicular enlargement. Sonography is commonly performed to evaluate the patient for epididymitis or torsion. The appearance of testicular malakoplakia on sonography examination has only rarely been described, making its diagnosis challenging. Because its appearance overlaps with testicular neoplasm and infection, it should be considered when making a differential diagnosis of a diffuse testicular abnormality in the appropriate clinical setting.

Malakoplakia of the thyroid gland: a case report and review of literature

Malakoplakia is a rare granulomatous disease that most commonly occurs in the urinary tract. It is characterized by sheets of histiocytes with granular basophilic inclusions and Michaelis-Gutmann bodies. We present an exceedingly rare case of malakoplakia of the thyroid in a 54-year-old Caucasian woman on immunosuppressive therapy for renal transplant performed in 1994.

Endoscopic mucosal resection of a rectal malakoplakia in a healthy adult

Malakoplakia in the gastrointestinal tract is rare in healthy young people without underlying disease. Sufficient tissue is required for accurate diagnosis. We describe a malakoplakia that developed in a healthy young woman and was treated by endoscopic mucosal resection (EMR). A 40-year-old woman with a history of taking oral contraceptives until one year earlier was referred to our hospital with anal bleeding and constipation. A colonoscopy carried out at our another hospital 18 months earlier disclosed no abnormal findings. Colonoscopy at presentation revealed a yellowish-white tumor, 5 mm in diameter, in the rectum. The lesion was slightly protruded and had a smooth flat surface, without erosion or ulceration. EMR was carried out for a definitive diagnosis. Histopathological examination showed that the tumor contained granular histiocytes, positive for CD68 and negative forcytokeratin (AE1/AE3). Several histiocytes contained intracytoplasmic round bodies (Michaelis-Gutmann bodies), which reacted positively with periodic acid-Schiff and calcium (Von Kossa) stains. Intracytoplasmic Escherichia coli (von Hansemann bodies) were identified by Giemsa staining. Based on these results, the tumor in the rectum was diagnosed as a malakoplakia. Following EMR, the patient did not receive further treatment for malakoplakia because she had no symptoms associated with malakoplakia. She has been well for more than 9 months, with no symptoms of disease. Awareness of colorectal malakoplakia is important in patients taking steroids, including oral contraceptives.

Primary extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue type with malakoplakia in the urinary bladder: a case report

Primary malignant lymphoma of the urinary bladder is a rare disease constituting less than 1% of neoplasms of the urinary bladder. The most prevalent histological subtype is extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue type (MALT lymphoma). It is frequently associated with chronic cystitis and predominantly occurs in females. On the other hand, malakoplakia is thought to be a reactive granulomatous lesion occurring most prevalently in the genitourinary tracts. It is frequently found in females and often associated with bacterial infection in immunosuppressive status. Here we report a rare case of concurrent primary MALT lymphoma and malakoplakia in the urinary bladder in a 78-year-old Japanese female. Presumably, both lymphoma and malakoplakia are considered to be involved in the antecedent cystitis and might contribute to the development of the urinary bladder tumor of the patient, leading to the occlusion of the right ureter with subsequent hydronephrosis.

Malakoplakia with digestive tract involvement in a pig

Malakoplakia is a rare, granulomatous, inflammatory disease that mimics malignant tumors and can affect any organ. Herein is described a case of malakoplakia in a 10-month-old slaughter pig. Diffuse, pleomorphic, round cell infiltrates, mainly histiocytes, with a tumor-like growth pattern at gross examination, infiltrated the stomach, pancreas, omentum, and mesenteric lymph nodes. The histiocytes and multinucleated giant cells had concentric, target-like inclusions known as Michaelis-Gutmann bodies. Microorganisms were not detected by the periodic acid-Schiff reaction, Ziehl-Neelsen, Gram, and Warthin-Starry staining or by electron microscopic and bacteriologic investigations. Porcine circovirus type 2 and porcine reproductive and respiratory syndrome viruses were not detected by immunohistochemistry in the sections examined.

Pseudotumor of the tracheal-laryngeal junction with unusual morphologic features caused by Rhodococcus equi infection

Infectious pseudotumors are unusual proliferations of histiocytes in response to certain microbial organisms. Occasionally this process may involve large airways, producing a mass lesion that may cause respiratory obstruction. Infectious pseudotumors can be confused with malignancy in their radiologic appearance and clinical presentation. We present a case of an aggressive endotracheal pseudotumor associated with Rhodococcus equi infection in a patient with advanced HIV disease. Microscopically, the lesion was composed of sheets of epithelioid histiocytes with large, strongly eosinophilic intra-cytoplasmic granules and features of malakoplakia. In this report, we review the literature of these unusual lesions and compare them to cases of conventional malakoplakia involving the large airways. We also explore the pathogenetic mechanisms that may contribute to the distinctive histologic appearance of Rhodococcus-associated pseudotumors.

Concurrent malakoplakia of cervical lymph nodes and prostatic adenocarcinoma with bony metastasis: case report

SummaryAn unusual case of malakoplakia of the cervical lymph nodes in a patient with bony metastasis from prostrate cancer is reported. An 80-year-old patient with metastatic prostatic cancer presented with bilateral cervical lymphadenopathy, and a hard cervical mass in the left supraclavicular region. Biopsy of the lymph gland revealed the presence of malakoplakia, with no evidence of metastatic prostatic carcinoma. Though co-existence of malakoplakia and adenocarcinoma within the prostrate gland has been reported before, this case is unique, as it highlights the rare occurrence of malakoplakia involving distant nodes in a patient with bony metastatic prostate cancer. This report reflects the fact that things are not always what they seem in medicine, and not infrequently we come across a different pathology which mimics another.