Malakoplakia of the Maxilla

Introduction

Malakoplakia is a rare inflammatory disorder which typically occurs in immunocompromised patients secondary to impaired bactericidal activity of macrophages. Histopathologically, it is characterized by a dense infiltrate of histiocytes with eosinophilic cytoplasm and Michaelis-Gutmann bodies, which are basophilic, round inclusions within macrophages. Malakoplakia commonly affects the genitourinary and gastrointestinal tracts but has been reported in other organs. Oral cavity involvement, however, is exceptionally rare. Here we present the first reported case of maxillary malakoplakia in an immunosuppressed patient.

Materials and Methods

This case was submitted to the Oral Pathology Laboratory, Inc. at New York-Presbyterian Queens.

Case Report

A 66-year-old male with a history of lung transplant presented with a non-healing extraction site of the left maxilla. To rule out a diagnosis of malignant neoplasm, the submitting clinician performed an incisional biopsy. Multiple pieces of tan-brown soft tissue measuring 2.3 × 2.0cm in aggregate were submitted for histopathologic examination.

Microscopic examination revealed a lesion composed of diffuse sheets of ovoid to spindle cells containing foamy cytoplasm. Numerous round, basophilic inclusions, consistent with Michaelis-Gutmann bodies, were noted within the cells. The inclusions were positive with von Kossa stain, indicating the presence of calcium. Immunohistochemical studies for CD68 were strongly positive, confirming a dense macrophage infiltrate. GMS and PAS stains were negative for the presence of microorganisms.

Conclusions

This is the first reported case of malakoplakia affecting the maxilla. Forty-nine previous cases of malakoplakia affecting the head and neck region have been published, with only 9 intraoral cases reported. Malakoplakia should be considered in the differential diagnosis of patients presenting with non-healing surgical sites, especially in those with a history of immunosuppression. Early diagnosis and prompt treatment are essential for successful management of this rare disease.