Malakoplakia is a rare chronic granulomatous disease associated with impaired macrophage phagocytosis of bacteria. Because colonic malakoplakia presents with varied endoscopic appearances, its characteristic features have not been clearly defined, and differentiation from colorectal neoplasms during endoscopy may be difficult. We report a case of colonic malakoplakia with adenomatous features evaluated using magnifying narrow-band imaging (NBI). A patient receiving hemodialysis and corticosteroid therapy for immunoglobulin A nephropathy underwent total colonoscopy after a positive fecal immunochemical test. Two reddish polyps were identified in the ascending colon. Magnifying NBI showed either absent or regular surface patterns with fine, thread-like vessels, along with areas resembling adenomatous changes. Although malignant features were not observed, a definitive diagnosis could not be established endoscopically. Consequently, both lesions were resected using cold snare polypectomy. Histopathological examination revealed a granulation tissue-like inflammatory lesion composed of histiocytes containing Michaelis-Gutmann bodies in the lamina propria and submucosa, leading to a diagnosis of malakoplakia. Based on this diagnosis, a surveillance colonoscopy was scheduled for 1 year later.

To describe the clinicopathological spectrum of genitourinary malakoplakia (MPL) and to evaluate the feasibility and clinical impact of metagenomic pathogen detection (MetaPath) performed on archival formalin-fixed paraffin-embedded (FFPE) tissue. Clinical imaging, histopathology, immunohistochemistry, special stains and MetaPath results were retrospectively analysed in five MPL cases diagnosed between January 2019 and August 2025. The cohort comprised four men and one woman with a median age of 65.4 years. Four lesions arose in the prostate and one in the bladder. Histology showed chronic granulomatous inflammation with numerous eosinophilic histiocytes containing 5-10µm targetoid Michaelis-Gutmann bodies. CD68 and CD163 were diffusely positive; PAS and iron stains highlighted the inclusions. MetaPath identified pathogens in 3/5 (60%) FFPE specimens (Escherichia coli in two, Pseudomonas aeruginosa in one). Antibiotic regimens were adjusted according to MetaPath results. After a median follow-up of 6 months (range 4-8) all patients remained symptom-free. MPL is frequently misdiagnosed as malignancy. MetaPath can reliably detect pathogens in archival tissue and guide targeted antimicrobial therapy, representing a valuable adjunct to conventional culture.

To the Editor More than a century has passed since 1903, when Professor David von Hansemann described the presence of macrophages deposited in the form of a soft plaque and coined the term of Greek origin, malakoplakia (MLP). A year later, the morphologyof this cell with its own name was completed by the contribution of Michaelis and Gutmann, who pointed out the inclusions in its cytoplasm...

Colonic Malakoplakia of Post-Renal Transplantation in a 31-Year-Old Female Case

Abstract Introduction/Objective Malakoplakia is a relatively rare inflammatory condition defined by histiocytic infiltration with pathognomonic intracytoplasmic inclusions known as Michaelis-Gutmann bodies. The lesion has been strongly associated with immunosuppressed states. Although the exact mechanism is unknown, an infectious component, such as impaired bactericidal activity in macrophages is highly implicated which leads to deposition of calcium and iron on residual bacterial glycolipid. Although commonly identified in the genitourinary tract, malakoplakia has been found in virtually all organ systems. Methods/Case Report We hereby present a 44-year-old male with a history of renal transplantation, presenting with a history of chronic diarrhea for one year. Colonoscopy was performed which identified diverticulosis in the sigmoid colon and a 5 mm sessile rectal polyp. Histopathological examination of the polyp biopsy demonstrated chronic active colitis, histiocyte aggregates and numerous intracellular, basophilic, concentric, laminated and targetoid calcified structures that were highlighted by Von Kossa and iron stains. These structures are known as Michaelis-Gutmann bodies which are pathognomonic of malakoplakia. A literature review of 45 cases was completed by utilizing the PubMed database. The cases reviewed included involvement of the allograft, host kidney, bladder, colon, prostate, thyroid, submandibular gland, lung, and testicles. Many of the patients were managed with either long term antibiotics, reduction of immunosuppression, or excision of the lesion with improvement in symptoms and/or renal function. Results (if a Case Study enter NA) NA Conclusion Our case highlights the importance of diagnosing this benign entity on histology examination to allow early treatment and improvement in symptoms.

BackgroundMalakoplakia is a rare inflammatory condition, commonly affecting the genitourinary system of immunocompromised patients. Gastrointestinal malakoplakia has been reported in the literature, with previous endoscopic findings mimicking mass lesions.PurposeTo describe a case of colonic malakoplakia after referral for endoscopic management of a large non-pedunculated colorectal polyp.MethodCase report and review of the literature.Result(s)Case ReportAn 80-year-old male with chronic kidney disease and remote renal transplant on immunosuppressive therapy (mycophenolate mofetil, tacrolimus, prednisone) was referred for endoscopic resection for a large non-pedunculated colorectal polyp in the cecum. Original presenting symptoms included chronic diarrhea, iron deficiency anemia, and fecal immunochemical test (FIT) positivity. A repeat colonoscopy demonstrated a 40mm Paris 0-IIA plaque-like lesion in the cecum with optical features not in keeping with adenomatous or serrated histopathology. Biopsies were performed with histopathology demonstrating normal colonic mucosa with confluent sheets of histiocytes with concentrically layered cytoplasmic inclusions, in keeping with malakoplakia.Literature reviewMalakoplakia, Greek for “soft plaque”, is a rare inflammatory condition characterized by impaired dysfunction in macrophages leading to the accumulation of incompletely degraded bacteria in phagolysosomes. Histologically, this appears as concentrically layered cytoplasmic inclusions, comprising the pathognomonic Michaelis-Gutmann bodies. Many bacterial organisms have been implicated in the development of malakoplakia, with E. coli being the most common; specifically in immunocompromised patients, whether from immunosuppressive medications, immunodeficiency syndromes, or clinical conditions precluding effective immune function. Malakoplakia commonly presents as a mass-like lesion and has been found in all organs, most commonly in the genitourinary system. Diagnosis is made by biopsy and allows for appropriate treatment, which is most commonly a reduction in immunosuppressive therapy and antibiotic therapy.ImageConclusion(s)Malakoplakia is rare but should be considered when a lesion with atypical optical evaluation features is found in immunocompromised individuals or those with recurrent infections.Please acknowledge all funding agencies by checking the applicable boxes belowNoneDisclosure of InterestNone Declared

Introduction: Malakoplakia is a rare histiocytic inflammatory response that is usually found in the urinary tract. Gastrointestinal involvement is considered the second most common location affected and is a result of dysfunctional macrophages. Histopathology is characterized by granular histiocytes with Micahelis-Gutmann bodies. Although usually an incidental finding, Malakoplakia is associated with immunosuppressive therapy, colorectal carcinoma and infectious diseases. Case Description/Methods: A 54-year-old man with a pmhx of alcohol use disorder was referred to clinic for acute, asymptomatic liver enzyme abnormalities. Laboratory findings were significant for AST of 270 U/L, ALT of 63 U/L, ALP of 65 U/L, and total bilirubin of 0.3 mg/dL. Further workup showed positive hepatitis B surface antigen, reactive hepatitis B core antibody and hepatitis B DNA by PCR was 172K IU/mL. Patient underwent screening colonoscopy which revealed a 2 mm sessile polyp in the cecum (Figure A). Histological examination of the polyp showed von-Hansemann cells containing Michaelis-Gutmann bodies, which is diagnostic for malakoplakia (Figure B). Discussion: The first report of colonic malakoplakia was described by Terner and Lattes in 1965 and usually involves the ascending colon, sigmoid colon and rectum. Clinical manifestations of colonic involvement range from asymptomatic to abdominal pain, fever, diarrhea and rectal bleeding. The lesion is characterized by von-Hansemann cells which are aggregates of histiocytes with eosinophilic cytoplasm and intracytoplasmic Michaelis-Gutmann bodies. Pathogenic mechanisms include a causative organism, altered immune response and phagocyte disfunction. Escherichia coli is the most common isolated pathogen found in 90% of patients with malakoplakia. These chronic bacterial infections are due to suspected abnormal macrophage function resulting in the inability to break down bacteria. The most susceptible include immunosuppressed patients who are post-transplant or have an untreated systemic disease such as chronic hepatitis. Antibiotic therapy, immunotherapy modification and surgical resection are the mainstay of management. While most cases of malakoplakia are diagnosed as incidental findings on screening colonoscopy, there does exist an associate with colorectal adenocarcinoma. Given the potential for significant morbidity if left untreated, malakoplakia diagnosed on incidental screening should prompt a work up for systemic infections, immune compromising diseases and malignancy.Figure 1.: A: Two mm cecum polyp denoted by yellow arrows. Figure B: High-power view of Malakoplakia (60x). Macrophages containing basophilic targetoid structures, known as Michaelis-Gutmann bodies.

Prostatic malakoplakia (MP) is rare, with only case reports and small series (< five patients) available in the literature. In this study we analysed an international multi-institutional series of 49 patients with prostatic MP to more clearly define its clinicopathological features. The median age was 67 years and the median serum prostate-specific antigen (PSA) was 7.5 ng/ml. MP was clinically manifest in most cases (28 of 45 patients with data available, 62%). Of 43 patients with detailed clinical history available, 21 (49%) had concurrent or metachronous malignancies (including prostate cancer). Diabetes or insulin resistance was present in 11 patients (26%). Additionally, three patients had a history of solid organ transplantation and one had HIV. Of note, six of 34 patients (18%) without concurrent prostate cancer had an abnormal digital rectal examination and/or lesions on magnetic resonance imaging (MRI) with prostate imaging reporting and data system (PIRADS) scores 4-5. The initial diagnosis was made on core biopsies (25 of 49, 51%), transurethal resection specimens (12 of 49, 24%), radical prostatectomies (10 of 49, 20%), Holmium-laser enucleation (one of 49, 2%) and cystoprostatectomy (one of 49, 2%). Tissue involvement was more commonly diffuse or multifocal (40 of 49, 82%). Von Kossa and periodic acid-Schiff stains were positive in 35 of 38 (92%) and 26 of 27 lesions (96%), respectively. Of note, two cases were received in consultation by the authors with a preliminary diagnosis of mesenchymal tumour/tumour of the specialised prostatic stroma. The present study suggests that prostatic MP is often associated with clinical findings that may mimic those of prostate cancer in a subset of patients. Moreover, MP may be found incidentally in patients with concurrent prostate cancer.

Introduction: Malakoplakia is a rare chronic granulomatous disease that can affect multiple organs including the genitourinary tract, lungs, brain, GI tract, and bone. The exact mechanism of action is unknown at this time, but is thought to be related to an acquired defect in macrophages. This defect is believed to lead to the decreased clearance of calcified cytoplasmic inclusions, also known as Michaelis-Gutmann bodies. The disease process is typically associated with immunosuppression, infection, and malignancy. The following is a presentation of a patient who initially presented with hematochezia and a colonic mass concerning for malignancy, and was subsequently found to have colonic malakoplakia. Case description/methods: A 48-year-old-male with a history of Hodgkin's lymphoma, non-ischemic cardiomyopathy, and heart transplant presented to the hospital with hematochezia. He was found to have a hemoglobin of 5.8 and iron deficiency. CT abdomen showed a large heterogeneous mass in the sigmoid colon that was concerning for malignancy. Colonoscopy was performed that revealed a partially obstructing mass in the sigmoid colon with surrounding oozing. The mass was biopsied which was negative for malignancy and showed extensive inflammation with no infectious cause identified. Given the uncertain diagnosis, a repeat colonoscopy was performed and deeper biopsies were obtained that showed malakoplakia. He was started on a course of ciprofloxacin/metronidazole and was discharged home. Repeat CT abdomen showed continued extension of the sigmoid mass with a contained perforation, and the patient ultimately required a sigmoid colectomy for definitive treatment. Discussion: Colonic malakoplakia can present in a myriad of ways, so it can be common to initially mistake malakoplakia for another process such as malignancy, IBD, or infection. A comprehensive history and physical is key to diagnosis of malakoplakia in order to properly assess for risk factors. Once diagnosis is made definitively by biopsy, early treatment is key to minimize complications. Initial treatment consists of antibiotics that facilitate the killing of bacteria by phagocytosis. Such antibiotics are the fluoroquinolones, trimethoprim/sulfamethoxazole, and rifampin. If medical therapy is not sufficient then surgical excision may be required. While colonic malakoplakia is rare it should remain on the differential diagnosis of a colonic lesion, especially when the patient has known risk factors and when there is difficulty making a definitive diagnosis.Figure 1.: A: Proliferation of macrophages with abundant granular cytoplasm infiltrating the entire thickness of the bowel causing mucosal ulceration (arrow). B: Characteristic cytoplasmic inclusions referred to as Michaelis-Gutmann bodies (arrows). C: CD68 (macrophage marker) of the mass lesion diagnosed as malakoplakia is shown. The macrophages are positive for CD68. D: The mass identified in the colectomy specimen is composed of sheets of macrophages with granular eosinophilic cytoplasm and PAS positive granules E: Von Kossa stain highlights the Michaelis-Gutmann bodies in malakoplakia. Partially digested bacterial products form the nidus for the calcium [von Kossa (+)] and iron depositions in these bodies.

Gallbladder malakoplakia masquerading as malignant primary on 18F-FDG PET/CT.

19. The many faces of colonic malakoplakia: A case series and review of the literature

WITHDRAWN: Well surgical outcome of malakoplakia and xanthogranulomatous pyelonephritis which presented in the same patient: A case report and literature review

INTRODUCTION: Malakoplakia is a rare chronic granulomatous condition related to a defect in macrophage phagolysosomal response in which engulfed bacteria are not destroyed. The urinary bladder is the most common site for malakoplakia to present and the gastrointestinal tract is a distant secondly reported site. Malakoplakia is often associated with conditions that cause immunodeficiency. We report a rare case of colonic malakoplakia (CM) in an asymptomatic, immunocompetent man with history of successfully treated hepatitis C virus (HCV) infection. CASE DESCRIPTION/METHODS: A 70-year-old African American man with a past medical history of treated HCV due to prior intravenous drug use, was referred by his primary care provider for screening colonoscopy. He was asymptomatic and clinical history was negative for inflammatory or other infectious diseases. He denied use of immunosuppressant medications. HCV RNA was undetectable. HIV serology was negative. No remarkable findings on physical examination. During colonoscopy, a single 5 mm sessile polyp was noted in the transverse colon and was removed (Figure 1). Histopathological analysis of polyp identified targetoid calcospherites on Von Kossa calcium stain consistent with Michaels-Gutman bodies, diagnostic of malakoplakia (Figures 2 and 3). On repeat colonoscopy four months later, a single 14 mm sessile polyp was found in the proximal descending colon with histopathology consistent with tubular adenoma. No findings suggestive of malakoplakia was noted, however, exam may have been limited due to poor bowel prep. DISCUSSION: In summary, malakoplakia has been reported to involve the urinary tract in approximately 75% of cases while the gastrointestinal tract is involved less than 10% of reported cases. CM is often associated with neoplasms such as adenocarcinoma, adenoma, and lymphoma and other non-neoplastic conditions such as infections, sarcoidosis, diabetes mellitus, alcoholic liver disease, immunosuppressive therapy, or other conditions of immunodeficiency. Though not previously reported, HCV could have played a role in development of CM. HCV as been reported to be associated with the development of cutaneous malakoplakia; therefore, we cannot exclude association of other extrahepatic manifestations. In conclusion, CM is a rare chronic granulomatous condition that can be incidentally found in immunocompetent individuals, more studies warranted to evaluate any association with HCV.

目的 探讨膀胱软斑病的诊治水平，提高对该病的认识。 方法 将1例膀胱软斑病患者的诊治过程进行报告，并结合文献进行复习。 结果 本组1例患者，男，82岁，以无痛性全程肉眼血尿为首发症状，超声及CT均提示膀胱内占位性病变，膀胱镜黏膜活检病理诊断为膀胱软斑病。 结论 膀胱软斑症的确诊依赖于病理组织学的检查，膀胱软斑症可采取保守治疗及膀胱肿物电切术。

A 71-year-old Caucasian male with history of smoking, hyperlipidemia and paroxysmal atrial fibrillation presented to clinic for colorectal cancer surveillance. Prior colonoscopy at an outside institution 5 years prior showed removal of four small polyps (unknown type) and surveillance was recommended. He had no symptoms and physical exam was normal. All laboratory tests and cancer screening tests were normal. During surveillance colonoscopy we noted four diminutive tubular adenomas and diffuse coalescent areas of raised erythematous plaques throughout the entire colon which were biopsied. Pathology of the plaques showed sheets of granular macrophages with numerous round targetoid spherules stainable for calcium and iron inclusions within histiocytes characteristic of Michaelis-Gutmann bodies, diagnostic for malakoplakia. Malakoplakia, from the Greek malakos (soft) and plakos (plaque), is a rare granulomatous inflammatory disease, predominantly in the genitourinary tract associated with Escherichia coli (75%), followed by the gastrointestinal tract (11%). It was described in 1902 by Michaelis and Gutmann as a collection of histiocytes with abundant eosinophilic cytoplasm (von Hansemann cells) with inclusions (Michaelis-Gutmann bodies) mixed with lymphocytes, plasma cells and neutrophils. The cells have low cGMP levels, which alter its microtubular functions for bacterial phagocytosis and lysosomal activity. Incompletely digested bacterial fragments undergo mineralization with calcium and iron salts, resulting in Michaelis-Gutmann bodies. Malakoplakia of the colon was first described in 1965 by Terner and Lattes in two different patterns: localized (associated with tumor) or diffuse (associated with immunocompromised state). This case exemplifies a rare finding, especially of the colon. Definitive diagnosis can be made by histological examination of von Hansemann cells and Michaelis-Gutmann bodies. Chronic bacterial infections and altered immune response are potential etiologies for diffuse disease, which further workup for HIV and quantitative immunoglobulins are being pursued in our patient. Furthermore, malakoplakia has been associated with colonic adenocarcinoma in 24 of 95 reported cases. This presentation serves as a clinical reminder of the association between malakoplakia and adenocarcinoma of the colon and the need for comprehensive colon cancer screening in these patients.

Malakoplakie de la glande sous-mandibulaire chez un patient transplanté rénal

Introduction: Malakoplakia is a rare, chronic granulomatous disease that is thought to occur as an acquired phagocytic deficiency in macrophages leading to an inability to fully digest bacteria first described in 1902.1-3 The majority of cases involve the genitourinary tract, however 11% of cases occur in the GI tract.3-5 Malakoplakia is rare in healthy people and is typically associated with chronic illness or immunosuppression.6 Case Report: Our asymptomatic 62 year old female patient was referred to our practice for average risk colon cancer screening. She was not taking medications. She denied abdominal pain, altered bowel habits, weight loss, or blood in her stool. Screening colonoscopy was performed and was notable for four pink-tan sessile polyps measuring 1 mm in the rectum. Cold forceps polypectomy was performed and cytohistochemistry was consistent with a diagnosis of malakoplakia. The patient confirmed no history of illness including autoimmune disease or chronic inflammatory conditions. Chemistry panel, CBC, hepatitis serologies, HIV, Immunoglobulin E, G, and M were all within normal limits. CT scan of chest, abdomen and pelvis showed no abnormalities. Endoscopic ultrasound of the rectum was normal. As patient was asymptomatic she received no further treatment. Discussion: Diagnosis of malakoplakia remains difficult given the variable clinical and endoscopic presentation.7 The endoscopic appearance of malakoplakia is heterogeneous.8-11 Accurate diagnosis requires histopathologic findings of histiocyte aggregates with eosinophilic cytoplasm, known as von Hansemann cells and the pathognomonic Michaelis-Gutmann bodies which are mineralized intracytoplasmic partially digested microorganisms within the lysosome that stain positive with periodic acid-Schiff, Von Kossa, and Prussian blue for their high glycogen, calcium, and iron content.6,12-17 The pathogenesis of malakoplakia is thought to involve infection followed by an inadequate host and inflammatory response.3,18-20 Previous studies have implicated bacteria as the source of infection with Escherichia coli being found in over 90% of cases21 but viruses, including HPV, have also been described.11 Roughly 40% of patients with malakoplakia have a primary or acquired immunodeficiency.22 Treatment includes cessation of immunosuppressive therapy, surgery, cholinergic agonists, or antibiotics.6,23-28 In asymptomatic cases such as ours, no treatment may be necessary.

A 54-year-old man was referred to our department for colorectal cancer screening. The colonoscopy revealed, at the ascending colon, several white plaques, some confluent, interspersed with normal mucosa (Fig. 1). Biopsies were performed and the histopathological examination showed a fragment of polypoid colonic mucosa with optically empty vacuoles in the lamina propria (Fig. 2) and irregular cystic spaces of varying sizes, similar to adipocytes in the absence of inflammation or dysplasia. Colonic pseudolipomatosis is a benign and rare condition, with an estimated prevalence of 0.02-0.3% in colonoscopic series, characterized by the presence of vacuoles with gas content in the lamina propria of the large intestine [1]. The incidence is more frequent between the sixth and seventh decade of life [2]. The pathogenesis remains unclear, but it is now considered to be an iatrogenic change caused by penetration of gas into the mucosa during endoscopy [1,2]. The endoscopic aspect is typical, with whitish or yellowish, single or multiple, mucosal plaques [1,2]. The plaques extend over several mm to 4 cm and can be found equally in the right and left colon [3]. The histological aspect is characterized by presence of optically empty vacuoles measuring 20-240 μm and displacing adjacent lamina propria. These clear spaces have no epithelial lining and are morphologically similar to adipocytes but without lipid content, based on histochemistry and ultrastructure [3]. The differential diagnosis includes cystic pneumatosis, colonic lymphangioma and colonic malakoplakia [2,3]. Conservative management is adequate since the lesions regress spontaneously without complications within weeks.

Introduction: Malakoplakia is an uncommon inflammatory condition usually associated with an underlying immunodeficiency, gram negative infection, or malignancy. Most cases are of genitourinary etiology. We describe a case of malakoplakia with simultaneous presentation in the pancreas and colon in an immunocompetent host. Case Report: A 69-year-old male presented to his primary care provider for evaluation of fatigue, 20-pound weight loss, and early satiety. Physical exam was significant for a cachectic appearing male, with a benign abdominal exam. Fecal occult blood test was positive. Laboratory investigation revealed a Hgb of 9.4 g/dL, transferrin saturation 8%, and a ferritin of 39.5 ng/mL. Other labs included a WBC count of 6.2 K/uL (with a normal differential), platelet count 263 K/uL, and INR of 1.74. LFTs were within reference range. HIV was negative. Due to his profound anemia, he was referred for colonoscopy which was significant for an 8-mm nodular submucosal collection of macrophages consistent with malakoplakia. Upper endoscopy was unremarkable. A computed tomography scan of his abdomen demonstrated a 5.8 x 5.2 cm pancreatic head mass. An endoscopic ultrasound confirmed this finding in the setting of an otherwise normal pancreatic parenchyma and pancreatic duct. Fine needle aspirate of the pancreatic head mass was significant for Michaelis-Gutmann bodies. Colon and pancreas specimens were negative for bacteria or malignancy. The patient is currently undergoing empiric antibiotic treatment and is doing well. Discussion: Malakoplakia is an uncommon form of chronic inflammation with usual involvement within the genitourinary tract. Other involved organ systems include the gastrointestinal tract, integumentary system, respiratory tract, central nervous system, HPA axis, and lymphatic system. The Michaelis-Gutmann body is pathgnomic, being described as a phagolysome encrusted with calcium and iron salts. The etiology of Michaelis-Gutmann bodies are thought to be an abnormal response to incompletely digested bacterial fragments and hence has been associated with chronic bacterial infections. Most cases of colonic malakoplakia are associated with colonic adenocarcinoma. Cases of malakoplakia of the pancreas are limited and are usually associated with pancreatic adenocarcinoma. Our case report is the first to our knowledge of a patient presenting with concomitant malakoplakia of the colon and pancreas outside the setting of an immunocompromised state or malignancy. This case highlights the fact that not all cases of iron deficiency anemia are “colon cancer until proven otherwise” and vigilance for zebras should always be present in the clinician’s mind.

Purpose: Malakoplakia is an uncommon condition, inflammatory in nature, usually involving the genitourinary system. It is characterized by presence of foamy histiocytes with characteristic basophilic inclusions known as Michaelis-Gutmann bodies. Gastrointestinal malakoplakia usually involves rectum and colon, often associated with colonic malignancy. We present a case of disseminated gastrointestinal malakoplakia with involvement of upper and lower GI tract, in the setting of high grade Myelodysplastic syndrome (MDS) evolving into acute myeloid leukemia (AML). Case: A 78 year old female with history of hypertension and hypothyroidism, presenting with malaise, anorexia, weight loss, fever, leukocytosis and severe anemia. A CAT scan of abdomen suggested an ill-defined right lower quadrant mass with diffuse thickening of terminal ileum and cecum. Colonoscopy suggested an ulcerated mass lesions in the cecum and the hepatic flexure. There were multiple nodules in sigmoid colon. Upper endoscopy suggested an unusual appearing mass in distal duodenum with whitish exudates on biopsy. All biopsies from the upper and lower GI lesions confirmed malakoplakia with the presence of characteristic inclusions. She had a complicated hospital course with respiratory failure. She received broad spectrum intravenous antibiotics. A repeat CAT scan in a few weeks suggested significant improvement in the size of mass lesion and resolution of ileal thickening. The bone marrow biopsy confirmed high grade MDS quickly evolving into AML. She rejected chemotherapy and was briefly leukopheresed preceding her transfer to hospice care. Discussion: Malakoplakia was first described in 1902, by Michaelis and Gutmann. GI involvement in a disseminated fashion is rare, particularly with duodenal involvement. We did not find a similar case scenario on review of literature, particularly in the setting of MDS/AML. Conclusion: Malakoplakia (meaning soft plaque in Greek) of gastrointestinal tract is a rare entity. The pathogenesis of malakoplakia is unknown. It may result from chronic infection with bacteria such as atypical mycobacterium, an abnormal immune reaction in a immune-compromised patient or an abnormal macrophage reaction. It is often a sign of underlying defective immune function, as seen in patients with hematologic malignancies or chemotherapy side effects. Presentation is variable depending on the location and extent of the involvement. Treatment with broad spectrum intracellular antibiotics is recommended. Our patient's malakoplakia partially improved with antibiotics despite her ongoing rapidly progressive high grade MDS/AML, suggesting a bacteriologic etiology of malakoplakia in the presence of a defective immune response.