A 4-year old male presented with a history of bleeding from the rectum and weight loss of approximately six-months duration. Physical examination showed an anemic, chronically ill child. No other specific diagnostic features were appreciated on general physical examination. Hematologic examination showed microcytic hypochromic anemia. Stool examination did not reveal any ova or parasites. Rectal examination showed multiple small polyps in the rectum. Proctoscopic examination under general anesthesia revealed diffusely hemorrhagic, inflamed, and edematous rectal mucosa and multiple rectal polyps. A mass involving the ascending colon was seen laparoscopically. Transverse mesocolon and mesentery of small bowel had multiple enlarged lymph nodes. Multiple biopsies were taken from transverse mesocolon and mesentery of small intestine and sent for histopathologic evaluation.
A. Xanthogranulomatous inflammation
C. Whipple's disease
D. Polyposis coli
B. Malakoplakia of rectum and anal canal in childhood
The histopathologic examination of the rectal mucosa revealed sheets of large macrophages with abundant eosinophilic cytoplasm mixed with lymphocytes and plasma cells. Interspersed between these cells, extracellularly as well as within the histiocytes, were lamellated, basophilic calcospherites (Michaelis-Guttman bodies) (Fig 1). These bodies showed strong positivity for PAS and calcium salts when stained with von-Kossa stain (Fig 2). The diagnosis of malakoplakia was made.
Malakoplakia is a disease of adulthood, rarely described in children and infants (1). We report a case of malakoplakia in intestinal tract of a 4 year old boy who presented with bleeding from the rectum. To the best of our knowledge there are only fifteen cases of intestinal malakoplakia that have been described in pediatric patients.
Malakoplakia is a disorder, characterized by accumulation of phagocytic macrophages (von-Hansemann cells) and lamellated basophilic calcospherites, which are called Michaelis-Guttman bodies. This lesion was originally described in urinary bladder as yellow, soft plaque like lesions on the mucosal surfaces. The term malakoplakia is derived from the Greek malakos, meaning soft, and Plax, meaning plaque.
After its original description in the urinary bladder, malakoplakia has been described in many sites, including other parts of the urogenital tract such as kidney, renal pelvis, ureter, prostate, testis, and epididymis, as well as gastrointestinal tract, respiratory tract, bones and skin (2,3). Gastrointestinal tract is the second most common site for malakoplakia after urogenital system. Most cases have been described in colon and rectum, with rare exceptions occurring in appendix and stomach.
Malakoplakia can affect any age group but is most common in the 5th to 7th decades of life. Malakoplakia in children is rarely seen and most reported cases are seen in the urogenital tract. Malakoplakia in children involving gastrointestinal tract is extremely rare and only few cases have been reported in English literature (4–9).
The etiology and pathogenesis of malakoplakia are not clearly understood. Ultra-structural examination of von-Hanseman cells has revealed engorged lysosomes that contain fragments of degenerated bacteria. On the basis of these observations, malakoplakia is presently regarded as a defect in the host macrophage response to a bacterial infection. An association with infection of urinary tract with gram-negative bacteria is well established, however a causal relationship is not proven.
Treatment of malakoplakia is mainly medical. However, in some cases patients have benefited from surgical removal of the lesion followed by medical therapy. The best long-term effective treatment is based on long-term use of antibiotics which penetrate the macrophages. The drugs, which have been used effectively, include trimethoprim-sulfamethoxazole and quinolones. (Fig. 1) (Fig. 2)
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