Custom Search

        

Ear Pathology Online

Pathology of Malakoplakia of the Ear

Dr Sampurna Roy MD

Dermatopathology Quiz Case 70

Diagnosis: Cutaneous Malakoplakia

 

Ear Pathology Online - Home Page

 

Ear Pathology Online -Index 

 

Rare cases of Malakoplakia have been reported in the middle ear.

Malakoplakia (from the Greek malacos, soft, and placos, plaques) is a rare granulomatous disease that occurs commonly in the urinary tract.

It was first described by Michaelis and Gutmann in 1902.

Other organs like the genito-urinary tract, testis, epididymis, lymph nodes, nasopharynx , tonsil and retroperitoneal tissue have been also involved though less frequently.  

Pathogenesis: 

1) Microorganisms might play a role in the pathogenesis. The organisms include Escherichia coli (found in more than two thirds of cases), Mycobacterium tuberculosis, Proteus, and Staphylococcus aureus.

Specific bacteria are found in certain categories of patients, for example, coliform bacteria in patients with chemotherapy and Rhodococcus equi in patients with acquired immunodeficiency syndrome.

2) An abnormal or altered immune response has been also implicated in the pathogenesis.

3) The third hypothesis is an abnormal macrophage response because of defective lysosomal function.

It is suggested that macrophages in malakoplakia are capable of phagocytosis but unable to digest the bacteria.

Partially digested bacteria accumulate in monocytes or macrophages and lead to the deposition of calcium and iron on residual bacterial glycolipid.

Gross features:

Grossly, malakoplakia can present as soft tan yellow plaques and nodules or even extensive bands.

The lesion is usually solitary but can be multiple.

Microscopic features:

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. 

The composition of Michaelis-Gutmann bodies has been shown to be 94.6% organic and 5.4% inorganic, with the inorganic components being calcium, phosphorus, and iron.

Further reading:

Malakoplakia outside the urinary tract

Malakoplakia of the middle ear

Malakoplakia of the middle ear.

Malakoplakia of the temporal bone in a nine-month-old infant

Scabies: 10 facts about Pathology of Scabies Infestation

 

Ear Pathology Online - Home Page

 

Ear Pathology Online -Index 

 

 

 

Dr Sampurna Roy  MD

Consultant  Histopathologist (Kolkata - India)


 

 

Histopathology-India.net

 

Pathopedia-India.com

 

Surgical Pathology.com

 

Pathology-India.com

 

Dermpath-India

 

Infectious Disease Online

 

Pathology Quiz Online 

 

Paediatric Pathology Online

 

Pancreatic Pathology Online

 

Paraganglioma-Online

 

Endocrine Pathology Online

 

Eye Pathology Online

 

Ear Pathology Online

 

Cardiac Path Online

 

Pulmonary Pathology Online

 

Lung Tumour Online

 

Mesothelioma-Online

 

Nutritional Pathology Online

 

Environmental Pathology Online

 

Soft Tissue Tumour Online

 

GI Path Online-India

 

Gallbladder Pathology Online

 

E-book - History of Medicine  

 

Microscope - Seeing the Unseen

 

 roypath.in

 

Disclaimer

Privacy Policy  

Advertising Policy

Copyright 2017  histopathology-india.net