Unusual presentation of oral amyloidosis.

Amyloidosis is a rare disease of difficult diagnosis that occurs due accumulation of amyloid substance localized or systemic. The oral cavity is an unusual site and can be related to both localized and systemic forms and for that reason a full investigation is necessary to determine the extent of the disease. This study reports a case of a 58-year-old melanoderm male patient referred to the Department of Oral and Maxillofacial Surgery with white plaques on the tongue and multiple nodules in the region of the buccal mucosa and labial commissure, with 6 months of evolution and painful symptoms. An incisional biopsy was performed on both sites and histological examination indicated the presence of eosinophilic amorphous material within the connective tissue, positive for crystal violet staining, consistent with amyloidosis. At the present time, there is no consensus on the management of local amyloidosis. Surgical treatment of localized forms is indicated in some cases to reduce the functional prejudice. Moreover, follow-up is mandatory, both to manage recurrences and to monitor the possible evolution of the disease to the systemic form.

Introduction

Amyloidosis is rare disease of difficult diagnosis that occurs due accumulation of amyloid substance localized or systemic.[1] On the localized form a single organ is affected, and the most common sites are lungs, brain, and skin.[2] On the systemic form, many organs may be affected, leading to significant morbidity and mortality.[2] Death is usually caused by kidney failure or arrhythmic episodes. Once it is diagnosed in the oral cavity, the patient must be supervised regularly to control potential systemic complications of the disease.[3] Some authors attest that localized form has a better prognosis, in particular when the head and neck area is affected.[3] Amyloidosis can be classified as primary, secondary, and familial. The subtypes are currently named according to the specific protein that is deposited, using the prefix A for amyloid, followed by letters that indicate the protein. Amyloid light chain amyloidosis is the primary systemic form and one of the most common subtypes, usually associated with plasma cell dyscrasia and multiple myeloma; the most common affected organs are kidneys, liver, heart, and nerves. Amyloid A or secondary systemic amyloidosis, is usually associated with other chronic infectious or inflammatory diseases, such as osteomyelitis, tuberculosis, rheumatoid arthritis, and Crohn's disease.[4] On the head and neck area, the most common affected sites are the larynx, subglottis, and thyroid.[2]

Amyloidosis of the oral cavity is less frequent, and usually appears as multiple soft nodules on the mucosa, and can be associated to a localized disease. When tongue is affected, it can result in macroglossia and be associated to systemic form.[5] After oral amyloidosis diagnosis, systemic involvement should be evaluated.[6]

Case Report

A 58-year-old melanoderm male patient, former smoker with a history of hypertension and rheumatic disease, was referred to the Department of Oral and Maxillofacial Surgery with complaints of white plaques on the tongue with 6 months of evolution and painful symptoms. The clinical examination revealed the presence a white plaque with approximately 3 cm on the lateral border of the tongue, with soft consistency [Figure 1]. The patient also had multiple nodules in the region of the buccal mucosa near labial commissure of the right side, with approximately 1 cm each, painful symptoms, firm consistency and spontaneous bleeding [Figure 1]. The patient presented cervical lymphadenopathy. The incisional biopsy was taken from the tongue and the buccal mucosa. The histological examination revealed a fragment of mucosa with squamous epithelium in the surface and adjacent connective tissue with mild inflammatory infiltrate. It could be observed the presence of eosinophilic amorphous and fibrillar material in corion positive for crystal violet staining, consistent with amyloidosis [Figure 2]. The most evident lesions of buccal mucosa were removed, and the patient was oriented about the recidive possibility. The systemic evaluation did not reveal other focus of amyloid deposition and the patient will continue to be monitored.

Figure 1

Clinical aspect of the white plaque on the lateral border of the tongue and nodules on the commissure

Figure 2

Epithelial hyperplasia and the presence of homogeneous, eosinophilic and amorphous material in corion consistent with amyloid. Positive crystal violet staining: Amyloid exhibit metachromasia

Discussion

Normal proteins, facing some systemic conditions such as cell changes and chronic inflammatory disorders, might form insoluble fibrils that can result in organ damage and dysfunction.[27]

Amyloidosis occurs more often in the seventh decade of life with a slight male predominance, which is consistent with the case presented. The patient of this report had a history of slow progression of the lesions, and the first hypothesis was a non-neoplastic proliferative process. The oral manifestations of amyloidosis are usually represented in the form of nodules, papules, plaques, and macroglossia and the color of the mucosa may range from yellow, orange, red, blue, and purple.[1] The involvement of the salivary glands can produce xerostomia.[3] In cases when gingival tissue is affected, amyloid is more likely to accumulate on mucogingival junction because of the increased collagen fibers.[8] Biopsy should also avoid inflammation areas that could lead to misdiagnosis.[1]

In the oral cavity, amyloid deposits are rare, but when it occurs, the tongue is usually the most involved anatomic site followed by the lip.[9] The disease can also present as periodontal disease, and lesions are exacerbated by the inflammation of the periodontium.[9] In the case described, the tongue presented white plaque on the lateral border, without macroglossia. Lesions were also found in the buccal mucosa, near the labial commissure, as soft nodules that could be misdiagnosed as a simple fibroma. The histopathological examination was important for definitive diagnosis.

Amyloid stained with hematoxylin and eosin coloration appears as a homogeneous, eosinophilic amorphous material and exhibit metachromasia with crystal violet; when stained with Congo red, it demonstrates green birefringence in polarized light.[4] Although the histopathological examination is important for diagnosis, other techniques for proteins and genomic DNA, analysis may help to elucidate and confirm diagnose.[8]

Occasionally, when there is a suspect of systemic amyloidosis and the biopsy of the involved organs is at high risk of morbidity, a gingival biopsy can be performed and is preferred even in the absence of gingival lesion.[4] After the diagnosis of oral amyloidosis, it is essential the exclusion of systemic involvement.[7] Furthermore, 25% of the patients with systemic amyloidosis present macroglossia.[10] Differential diagnosis with malignant neoplasia must be made.[8]

It is important to be alert to the clinical manifestations of the disease to establish an early diagnosis.[4] Physicians and patients should work together in order to better understand the molecular mechanisms involved in the transformation of the precursor protein into amyloid fibrillar structure and understand the role played by other tissue components in the formation and persistence of amyloid deposits, which may offer new knowledge that may increase therapeutic options.[4]

A therapeutic strategy for amyloidosis is to dissolve amyloid deposits and/or prevent their accumulation. Patients with localized amyloidosis generally do not require systemic therapy, and management can be supportive or localized.[10] Excision can be realized, although these lesions are often persistent or recurrent and follow-up is an alternative.[56] The treatment of oral localized amyloidosis is usually unnecessary, but surgical excision can improve patient's condition.[5]

At the present time, there is no consensus on the management of local amyloidosis. Surgical treatment of localized forms is indicated in some cases to reduce the functional prejudice. Moreover, follow-up is mandatory, both to manage recurrences and to monitor the possible evolution of the disease to the systemic form.[2]

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.