Palatal atypical histiocytic granuloma.

In this report, we examine a clinical entity called atypical histiocytic granuloma (AHG), which is characterized by ulceroproliferative lesions that clinically simulate a squamous cell carcinoma or specific granulomatous lesions. AHG histologically shows a histiocytic proliferation and is characterized by specific mitotic activity, which has the potential to be confused with malignant processes of a lymphoid origin. There are few cases reported in the literature, and an adequate knowledge of the process is required in order to avoid a misdiagnosis, especially as regards malignant processes. To our knowledge, a case of this type of lesion in the palate has not yet been described. We present a case of an atypical histiocytic granuloma which occurred in the form of an ulcerated pediculated lesion in the palatine mucosa (an uncommon localization that not yet has been researched). This case histologically showed a histiocytic infiltration with an increase in the mitotic index, eosinophils and an accumulation of haemosiderin. The lesion resolved spontaneously after the biopsy, without recurring after a period of five years. This report stresses the important value of immunohistochemistry in diagnosing the lesion and also discusses the similarities and differences between other lesions that may be confused, potentially leading to a misdiagnosis.