Langerhans cell histiocytosis (LCH) and adult-onset xanthogranuloma (AXG) are rare disorders characterized by the accumulation of macrophage, dendritic cells, or monocyte-derived cells in various tissues of the body. Many researchers now consider LCH a form of malignancy, but this classification remains controversial. As per our knowledge, there are only 36 cases of AXG reported so far in the English literature. Here, we report a case of AXG and single-system LCH found in the oral cavity and cervical lymph nodes, respectively. In this article, we intend to define a clear understanding of some classic clinical, radiological, and histopathological findings of LCH and AXG, to differentiate them from oral malignancies. The primary goal of this article is to increase awareness regarding conditions that closely resemble malignancies and to save patients from the burden of extensive treatment under the presumption of malignant disorders. In the medical field, reporting of rare cases is highly encouraged; however, proper treatment for the patient depends on the accurate diagnosis that, in this case, was made postoperatively, which only added more physical and mental distress for the patient and their family.

Vasculitis is an inflammatory disorder of blood vessels affecting multiple organs. A deficiency of adenosine deaminase enzyme type 2 (DADA2) is a novel condition identified as a monogenic cause of cutaneous vasculitis. Since its first description in 2014, numerous case series and literature across several countries have expanded the scope of our understanding of this rare genetic condition. However, due to a scarcity of reported cases in adults, little is known regarding its full spectrum of clinical presentations, treatment guidelines, or outcomes in the adult patient population. It is established that it commonly affects multiple organ systems, such as the skin, musculoskeletal, neurological, hematological, gastrointestinal, and renal systems. It presents with a wide range of clinical manifestations, including fever, Livedoid rash, cutaneous polyarteritis nodosa, polyneuropathy, and immunodeficiency. Such a varied clinical spectrum opens an opportunity for discussion to list some of the differential signs of DADA2. In this article, we report a unique case of a 26-year-old male with a delay of nine years in diagnosing a genetic mutation that led to DADA2. In addition, a 10-year history of recurring cutaneous ulcers and peripheral neuropathy makes this case a noteworthy addition to the literature on cutaneous vasculitis and its miscellaneous causes.