Pulmonary Malakoplakia Coexistent with Tuberculosis of the Hilar Lymph Node Mimicking Malignancy

Presacral malakoplakia presenting as foot drop: a case report

BACKGROUND

Malakoplakia is a rare condition characterized by inflammatory masses with specific histological characteristics. These soft tissue masses can mimic tumors and tend to develop in association with chronic or recurrent infections, typically of the urinary tract. A specific defect in innate immunity has been described. In the absence of randomized controlled trials, management is based on an understanding of the biology and on case reports.

CASE PRESENTATION

Here we describe a case of presacral malakoplakia in a British Indian woman in her late 30s, presenting with complex unilateral foot drop. Four years earlier, she had suffered a protracted episode of intrapelvic sepsis following a caesarean delivery. Resection of her presacral soft tissue mass was not possible. She received empiric antibiotics, a cholinergic agonist, and ascorbic acid. She responded well to medical management both when first treated and following a recurrence of symptoms after completing an initial 8 months of therapy. Whole exome sequencing of the patient and her parents was undertaken but no clear causal variant was identified.

CONCLUSIONS

Malakoplakia is uncommon but the diagnosis should be considered where soft tissue masses develop at the site of chronic or recurrent infections. Obtaining tissue for histological examination is key to making the diagnosis. This case suggests that surgical resection is not always needed to achieve a good clinical and radiological outcome.

Malakoplakia of the gastrointestinal tract: clinicopathologic analysis of 23 cases

Background

Malakoplakia is an uncommon, tumor-like inflammatory disease characterized by impaired histiocytes that are unable to completely digest phagocytized bacteria. The genitourinary tract is the most common site of involvement, however, cases have also been described in the gastrointestinal tract, suggesting that it is the second most common site of involvement. This study investigates the clinical and histologic features of malakoplakia in the gastrointestinal tract.

Case presentation

For 23 gastrointestinal specimens (biopsies and resections) from patients with a pathologic diagnosis of malakoplakia, we recorded the gender, age, location, primary diagnosis, endoscopic or surgical indication, endoscopic/gross impression and immune status (immunocompromised vs. immunocompetent).

Conclusion

Malakoplakia occurred throughout the length of the gastrointestinal tract with most of the cases located in the sigmoid colon and rectum (n = 10); other sites included the transverse and descending colon (n = 4), stomach/gastroesophageal junction (n = 4), appendix (n = 2), cecum (n = 1), small bowel (n = 1), and the peri-anal area (n = 1). Endoscopically, these lesions most commonly appeared as polyps (n = 10) or masses (n = 5), other clinical endoscopic impressions varied from a thickened area/fibrosis to mucosal erythema. Most patients were immunocompromised due to a disease state (e.g. organ transplantation, cancer diagnosis, autoimmune condition) and/or medication effect. Eight patients with malakoplakia were on immunosuppressive medications (8/23, 35%). Common immunosuppressed disease states included cancer (n = 9), autoimmune disease (n = 5), status post organ transplantation (n = 4), diabetes (n = 5), infection/sepsis (n = 3), and HIV/AIDS (n = 1). Some patients had multiple co-morbidities (i.e. diabetes and organ transplant). Twenty-one patients with malakoplakia were in an immunosuppressive state (21/23, 91%).

Cutaneous malakoplakia presenting as a groin swelling and graft failure

Malakoplakia (from the Greek malakos, 'soft' and plakos 'plaque') is a granulomatous inflammatory condition, commonly presenting as a plaque in the genitourinary system, but has been shown to affect a wide variety of structures including the skin. Presentation is varied and a high degree of clinical suspicion is needed to make a diagnosis. We report a case of cutaneous malakoplakia presenting as an inguinal swelling in a 48-year-old kidney transplant patient with temporally associated graft dysfunction. New groin swelling in an immunosuppressed patient often prompts investigation centred on a malignant cause. While this is often appropriate, less common infectious and inflammatory causes should be considered. This case highlights the importance of thorough workup and investigation, including histopathology, in immunosuppressed cohorts and acts as a reminder that less common and more complex diagnoses warrant consideration in this group.

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.

Rhodococcus equi Sepsis in a Renal Transplant Recipient: A Case Study

Rhodococcus equi is an unusual cause of infection in humans, but has emerged as an opportunistic pathogen among immunocompromised patients. Primary pulmonary involvement is the most common clinical presentation, although the spectrum of disease is broad. Diagnosing R. equi infections remains challenging, both from clinical and microbiological view, and no standard treatment has been established. In this report, we present a detailed case of a 57-year-old male renal transplant recipient who developed R. equi bacteremia with a concomitant Pneumocystis jirovecii pneumonia. We describe the clinical features of R. equi infections, highlight the importance of an early diagnosis, and briefly review treatment options for this rare infection.

Pulmonary malacoplakia at early stage: use of polymerase chain reaction for detection of Rhodococcus equi

Malacoplakia is a rare inflammatory condition characterized by the accumulation of benign macrophages associated with pathognomonic Michaelis-Gutmann bodies (MGBs). It is usually found in the genito-urinary tract, and has been associated with immunocompromised states. In this short report, we present 5 patients with pulmonary nodules clinically suspicious for primary or metastatic lung cancer. The histologic examination of the surgical specimens revealed a nonspecific granulomatous chronic disease, and despite the paucity of classical MGBs, a pulmonary malacoplakia was suspected. In all cases the opportunistic pathogen Rhodococcus equi (R. equi) was identified by 16S rRNA gene sequence analysis, leading to the final pathological diagnosis of malacoplakia. We conclude that pulmonary malacoplakia associated with R. equi is a rare disease affecting also immunocompetent patients. The pathogenesis and the diagnostic problems are discussed. Since infection by R. equi is treatable, the importance of its early recognition should be emphasized.

[Vesico-cutaneous fistula revealing abdominal wall malakoplakia accompanied by Boeck's sarcoidosis]

Malakoplakia is an acquired granulomatous disorder first described by Michaelis and Gutmann in 1902. The pathogenesis of malakoplakia is hardly known, but it thought to be secondary to an acquired bactericidal defect in macrophages occurring mostly in immunosuppressed patients.

CASE REPORT

63-year-old female patient had been treated with methylprednisolone for ten years, because of pulmonary sarcoidosis. For six month, recurrent abdominal abscess and vesico-cutaneous fistula developed. Histological examination proved malakoplakia, and Escherichia coli was detected in the abscess cavity.

METHODS

Hematoxyline eosin staining, periodic acid-Schiff, Berlin-blue and Kossa reactions were performed.

RESULTS

Microscopically malakoplakia consists of mainly macrophages, known as von Hansemann cells with scattered targetoid intracytoplasmic inclusions known as Michaelis-Gutmann bodies. In our presented case, after urological-surgical intervention and antibiotic therapy, the patient became free from complaints and symptoms.

DISCUSSION

Malakoplakia has been described in numerous anatomic locations, mainly in the urogenital tract. Malakoplakia may be complicated with fistulas in different locations: vesico-coccygeal, rectoprostatic, anorectal fistulas have been were reported in the literature, while 6 cases of malakoplakia with Boeck's sarcoidosis are published.

CONCLUSION

In the presented case sarcoidosis and the 10-year immunosuppressive treatment with methylprednisolone might have been in the background of abdominal wall malakoplakia, complicated by vesico-cutaneous fistula. The patient was successfully treated with surgery and the followed antibiotic therapy.

Malakoplakia Outside the Urinary Tract

Context.—Malakoplakia is a rare granulomatous disease that occurs commonly in the urinary tract. Histologically, it is defined by sheets of histiocytes (Hansemann cells) with accumulation of granular basophilic periodic acid-Schiff– positive, diastase-resistant inclusions and calcified Michaelis-Gutmann bodies, which are pathognomonic but not necessary for diagnosis. In addition to the urinary tract, malakoplakia has been reported in other organs, including the gastrointestinal tract, central nervous system, female genital tract, and the tongue.

Objectives.—To review the literature of reported sites of malakoplakia outside the urinary tract and their variable clinical presentations, and to discuss the main diagnostic features and differential diagnoses of malakoplakia. The pathogenesis and possible etiologic factors are also presented.

Data Sources.—Data for this work were collected from the published literature, textbooks, and the Internet.

Conclusions.—It is important to be aware of the existence of this entity in abnormal locations. In many situations, malignancy can be mimicked, especially when the lesion is ulcerated and is accompanied by lymph node involvement. Misinterpreting large, rapidly growing nodules of malakoplakia as tumor might lead to overstaging. Pathologists should be also aware of the possibility of malakoplakia coexisting with other lesions, such as tuberculosis and carcinoma, in the same specimen.