Malakoplakia of the appendix in a young healthy adult: a case report and literature review

Abstract

Malakoplakia is a rare entity on inflammatory base that mostly occurs in immunocompromised individuals which is thought to be secondary to a bactericidal defect in macrophages. The genitourinary tract is typically affected. The appendix is a very rare localization. We report a case of malakoplakia in the appendix of a young healthy patient with a recent history of abdominal pain associated with diarrhea and nausea. The colonscopy and CT scan showed an extramucosal bumping mass pressing on the cecum and covered by normal mucosa. The patient underwent to laparoscopic appendectomy. The histology showed a malakoplakia of the appendix. Gastrointestinal localization of malakoplakia is often associated with preexisting diseases, which are probably responsible for an immune disorder underlying the etiopathogenesis of the disease. However, in our case, the patient had no comorbidities. Probably, a clinically unknown immune predisposition plays an important role. Further studies are needed to clarify this nexus.

Keywords: appendix; case report; malakoplakia.

Figure 1

Submucosal cellular population is constituted by round histiocytic elements with a granular dense cytoplasm, containing typical eosinophilic bodies (arrow); haematoxylin and eosin, magnification ×20.

Figure 2

Submucosa is expanded and colonized by a dense histiocytic population (von Hansemann cells) and harboring microcalcifications; haematoxylin and eosin, magnification ×20.

Figure 3

Intracellular and extracellular Michaelis–Gutmann bodies surrounded by inflammatory cell infiltrate of histiocytes; haematoxylin and eosin, magnification ×40.

Figure 4

The most represented population is pancytokeratin negative, confirming its non-epitheliod and non-neoplastic nature; pancytokeratin, magnification ×10.