Diagnostic uncertainty in prostate health, illustrated with MRI scans and biopsy slides.

When Cancer Isn't: Unmasking Malakoplakia's Mimicry in the Prostate

Nico Varela in Health & Wellness December 2025 • 4 min read.

"Learn how a rare inflammatory condition can mimic advanced prostate cancer, leading to potential misdiagnosis and unnecessary treatment."

Prostate cancer is a leading health concern for men, often diagnosed through a combination of digital rectal exams, PSA tests, and biopsies. When these tests suggest advanced cancer, the next step is typically staging with multiparametric MRI (mpMRI) to determine the extent of the disease. However, what happens when the mpMRI paints a picture of cancer, but the biopsy results tell a different story?

This article explores a rare and challenging case where an inflammatory condition known as malakoplakia mimicked the appearance of locally advanced prostate cancer on mpMRI. We will delve into the diagnostic complexities, the importance of considering unusual conditions, and the potential impact on patient care and treatment decisions.

The original research recounts the experience of a 66-year-old man whose case highlighted the difficulties in differentiating between aggressive prostate cancer and this rare inflammatory condition. By understanding this case, healthcare professionals and concerned individuals can better navigate the complexities of prostate health and avoid potential misdiagnoses.

The Case: A Cancer Imposter

Diagnostic uncertainty in prostate health, illustrated with MRI scans and biopsy slides.

A 66-year-old man presented with an abnormal digital rectal exam and an elevated PSA level, raising suspicion for prostate cancer. A subsequent biopsy revealed adenocarcinoma, but the location and extent of the cancer seemed inconsistent with the clinical exam. To resolve this discrepancy, a multiparametric MRI (mpMRI) was performed.

The mpMRI revealed a concerning 4.5 x 2 cm mass in the left mid-prostate, exhibiting characteristics typically associated with aggressive cancer: strong restricted diffusion, loss of the fat plane with the rectum, and minimal washout on DCE. A second lesion in the right base showed similar aggressive features, even suggesting invasion into the seminal vesicle.

Discordant Findings: The MRI suggested advanced cancer, but the biopsy results didn't fully support this.
Treatment Dilemma: Doctors faced a challenge in determining the best course of action.
Patient Choice: After careful consideration, the patient opted for radical prostatectomy.

Post-surgery pathology revealed a surprise: instead of advanced cancer, the patient had malakoplakia, a rare inflammatory condition, extending into extraprostatic tissue. This case underscores how malakoplakia can convincingly mimic prostate cancer on mpMRI, leading to potential misdiagnosis and overtreatment.

Why This Matters: Lessons Learned

This case highlights the importance of considering rare inflammatory conditions like malakoplakia in the differential diagnosis of suspected prostate cancer. While mpMRI is a valuable tool, it is not foolproof, and its findings must be interpreted in the context of clinical and pathological data.

The rising rates of infectious complications after prostate biopsy may increase the incidence of such inflammatory conditions. Therefore, clinicians should be vigilant in recognizing the potential for these conditions to mimic cancer, impacting treatment decisions.

Ultimately, this case underscores the need for a comprehensive and individualized approach to prostate cancer diagnosis and treatment, considering all available evidence and exploring less common possibilities to ensure the best possible outcome for the patient.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.5489/cuaj.3235, Alternate LINK

Title: Malakoplakia Of The Prostate Masquerading As Locally Advanced Prostate Cancer On Mpmri

Subject: Urology

Journal: Canadian Urological Association Journal

Publisher: Canadian Urological Association Journal

Authors: Robert Thomas Dale, Michael Metcalfe, Silvia Chang, Edward Jones, Peter Black

Published: 2015-12-14

Everything You Need To Know

What is malakoplakia, and how does it relate to prostate health?

Malakoplakia is a rare inflammatory condition that can mimic the appearance of advanced prostate cancer in imaging tests, specifically multiparametric MRI (mpMRI). It's characterized by the presence of immune cells and often presents as a mass. The case described involved a 66-year-old man whose mpMRI showed features suggestive of aggressive cancer, leading to a radical prostatectomy. However, the post-surgery pathology revealed malakoplakia, not cancer, highlighting the mimicry.

Why is it important to consider malakoplakia in the context of potential prostate cancer?

The significance lies in the potential for misdiagnosis and overtreatment. If an mpMRI suggests advanced prostate cancer due to malakoplakia, the patient may undergo unnecessary procedures like radical prostatectomy. This situation underscores the importance of considering rare conditions like malakoplakia in the differential diagnosis. Accurate diagnosis is crucial to avoid exposing patients to the risks associated with treatments like surgery, radiation, and hormone therapy, which are not appropriate for malakoplakia.

What role does multiparametric MRI (mpMRI) play in diagnosing prostate issues, and what are its limitations?

Multiparametric MRI (mpMRI) is a powerful imaging technique used to assess the prostate and determine the extent of suspected prostate cancer. It can detect various features associated with cancer, such as restricted diffusion and loss of the fat plane. However, as demonstrated in this case, mpMRI can sometimes misinterpret the appearance of other conditions. When the mpMRI findings are inconsistent with other clinical data, it's vital to consider alternative diagnoses like malakoplakia.

What are the diagnostic challenges presented by malakoplakia?

The diagnostic challenges arise from the ability of malakoplakia to mimic aggressive prostate cancer on mpMRI. This mimicry can lead to incorrect conclusions about the presence and severity of cancer. When the mpMRI findings appear suspicious, but the biopsy results are not fully consistent, clinicians face a dilemma. They must carefully assess the clinical picture, possibly including additional tests and consultations, to avoid misdiagnosis. The case described demonstrates how discordant findings require deeper investigation to guide the right treatment.

Why is it crucial to consider rare conditions like malakoplakia in prostate cancer diagnosis?

Considering rare conditions like malakoplakia is essential to avoid misdiagnosis and ensure accurate patient care. Relying solely on mpMRI without considering other possibilities can lead to unnecessary interventions. The case emphasizes that clinical and pathological data must always be considered in conjunction with imaging findings. This integrated approach allows healthcare professionals to make informed decisions, protecting patients from the potential harms of incorrect treatment.