Foreign Bodies in Sinonasal Tissues: A Potential Pitfall yet a Hint to Oroantral Fistulas.

Foreign bodies in the maxillary sinus are infrequent findings with various organic and inorganic materials have been reported. Most are iatrogenic due to abnormal communications between the oral cavity and the sinus cavity, predominantly secondary to dental and oral procedures. Oroantral fistulas might be asymptomatic incidental findings or may present with sinusitis-related symptoms. Even though oroantral fistulas are frequently encountered iatrogenic complications, most studies focused on radiologic findings and surgical closure procedures. A few cases reported the histopathologic findings of foreign body-related antral sinusitis. Our aim is to report three cases of chronic maxillary sinusitis induced by various foreign bodies of oral and dental origin associated with oroantral fistulas. Our focus is to highlight the different histopathologic patterns, potential pitfalls and helpful clues of foreign body-induced maxillary sinusitis. Altered foreign bodies in procured sinus specimens might be missed, misinterpreted or ignored by pathologists. Obvious vegetable food remnants were detected, but subtle vegetable residuals showed pulse granuloma, rings and sheet-like patterns embedded in the granulation tissue and fibrous stroma. Some materials mimicked fungal hyphae while others were ignored as nonspecific debris. Periodic acid Schiff stain and polarizing light helped delineate their nature. Other helpful hints included the presence of oral-type squamous epithelium, crystals, hemosiderin pigments, dental materials such as alvogyl, and microorganisms of oral origin for example Actinomyces. Our series emphasizes the importance of correct recognition of foreign bodies of oral and dental origin in paranasal specimens to guide clinicians to the possibility of oroantral fistula-associated odontogenic sinusitis versus conventional rhinosinusitis.

Oral manifestations of Langerhans cell histiocytosis with unusual histomorphologic features.

Langerhans cell histiocytosis (LCH) is a bone marrow-derived immature myeloid dendritic cell proliferative disorder with diverse clinical manifestations commonly involves bone, skin, lymph node and lung. Oral involvement is uncommon. Intraoral lesions can be the first sign of either a localized LCH or clinically undiagnosed systemic LCH, predates systemic manifestations of LCH, or an early indicator of recurrence in known cases. Clinically, it can be mistaken for primary oral and dental inflammatory, infectious and neoplastic lesions. Histologically, diagnostic challenges may arise because of the nature of oral and dental specimens, different tissue reaction patterns and variations in histomorphology of LCH. We performed a retrospective review study over 10 years. We searched for diagnosed cases of LCH. We retrieved and reviewed cases of LCH with oral involvement. We found 54 cases of LCH, four (7.4%) with oral involvement. The age range was between 1 and 27 years with an average age of 13.7 years. They were males. They were clinically confused with abscess, cysts, infection, granulation tissue and other neoplastic lesions. Histologically, they showed different histopathologic features including different patterns of necrosis, granulomas, allergic-like inflammation, superimposed infection, stomatitis, cyst and sinus formation, foreign body giant cell reaction, and foci mimicking lymphomas and metastasis. Certain cytologic features were helpful hints. In doubtful cases, immunohistochemistry helped confirm the diagnosis. Because of the multiple fragmented nature of oral specimens with different tissue reaction patterns, the diagnostic Langerhans cells may be missed or misinterpreted. Oral LCH may be confused with infectious, inflammatory, benign and malignant neoplastic lesions because of its variable clinical presentations and its heterogeneous histomorphologic features. Pathologists have an important role in guiding clinicians to the correct diagnosis and patients' management. They should be familiar with the different histomorphologic patterns to avoid pitfalls. Attention to certain morphologic features and immunohistochemistry should help resolve challenging cases.

Be Aware of a Potential Pitfall in Oral and Dental Specimens: Alvogyl Fibers.

Alvogyl dressing is used to help control hemostasis, foster healing, and prevent complications after certain oral procedures. It is a paste composed of different antiseptic and analgesic substances, and fern-derived Penghawar djambi fibers that have styptic properties. It is claimed to be a resorbable and self-eliminating paste with little complications. However, some studies have demonstrated detrimental effects. We report 3 cases of postextraction nonhealing sockets after Alvogyl dressing. Histologically, they demonstrated residual Alvogyl fibers with foreign body giant cell stromal reaction and complications that were clinically confused with abscess, cysts, infections, and neoplastic lesions. Being unaware of their histopathologic appearances, the foreign bodies in 2 cases were initially confused with fungal hyphae, parasitic ova, vegetable material, and other surgical and nonsurgical materials. To add to our confusion, they were periodic acid-Schiff (PAS) and Grocott methenamine silver (GMS) positive, septated, spiked, and calcified. A history of Alvogyl dressing was retrospectively found. Learning from our mistakes and being aware of the histologic manifestations of Alvogyl fibers, the third case was correctly spotted. Because Alvogyl fibers are undissolvable and are not spontaneously eliminated, they may, if left for a long period, elicit tumefactive foreign body giant cell stromal and epithelial reactions that can be confused with inflammatory, infectious, and neoplastic lesions. Histologically, they can mimic infectious agents and noninfectious materials. Because history of dressing is not always provided, pathologists should be familiar with their histomorphologic features to avoid pitfalls and guide clinicians to correct diagnosis and management. In absence of history, certain histologic features are helpful hints.