Oral focal mucinosis: A systematic review.

Oral focal mucinosis (OFM) is a rare lesion first described in 1974, but the aetiology remains unknown. Clinically, OFM presents as an asymptomatic nodular lesion and the similarity of clinical features to other soft tissue injuries makes the diagnosis difficult. The aim of this study was to integrate the demographic, clinical, and histopathological characteristics from previously published cases of OFM into a systematic review. Electronic searches without publication date restriction were performed in the following databases: Embase, PubMed, Medline, Web of Science, and Scopus. Case reports or case series of OFM published in English and presenting enough clinical and histopathological information were included. This systematic review identified 42 studies from 12 countries, comprising 113 cases of OFM. This lesion affected more females than males, usually in the fourth decade of life. The gingiva was the most common anatomical location, followed by the palate. Clinical presentation was most often an asymptomatic nodule. Imaging exams revealed that most cases did not have bone involvement. Surgical removal was the treatment of choice for most cases and only one recurrent case was reported. In conclusion, OFM is an uncommon pathology, and its diagnosis depends on histopathological analysis. The lesion could be included as a differential diagnosis of benign soft tissue lesions of the oral cavity, especially those affecting the gingiva.

Papular Mucinosis.

This case report describes erythematous patches on the face that involved the nasolabial folds, as well as numerous skin-colored homogenous waxy papules on the arms, neck, and trunk.

Intestinal Submucosal Mucinosis in a Patient With Systemic Lupus Erythematosus: A Case Report.

Systemic lupus erythematosus (SLE) is an autoimmune disease with various clinical presentations. Mucin deposition is a characteristic finding in skin lesions, but it is rare in other organs. We present a case with erythematous patches from the terminal ileum to the anus in an SLE patient. Diffuse colitis was diagnosed clinically. However, in addition to inflammatory cell infiltration, there was abundant mucinous material deposition in the submucosa. The mucinous material was positive for Alcian blue staining (pH 2.5) and was sensitive to hyaluronidase digestion. These findings are similar to those of cutaneous mucinosis in SLE patients. This is thought to be the first case of gastrointestinal tract mucinosis in SLE reported in the literature.

Identifying the potential origin of mucin in primary cutaneous mucinoses-A retrospective study and analysis using histopathology and multiplex fluorescence staining.

BACKGROUND: Primary cutaneous mucinoses (PCM) are rare diseases characterized by dermal or follicular mucin deposits. OBJECTIVES: A retrospective study characterizing PCM to compare dermal with follicular mucin to identify its potential origin on a single-cell level. MATERIAL AND METHODS: Patients diagnosed with PCM between 2010 and 2020 at our department were included in this study. Biopsy specimens were stained using conventional mucin stains (Alcian blue, PAS) and MUC1 immunohistochemical staining. Multiplex fluorescence staining (MFS) was used to investigate which cells were associated with MUC1 expression in select cases. RESULTS: Thirty-one patients with PCM were included, 14 with follicular mucinosis (FM), 8 with reticular erythematous mucinosis, 2 with scleredema, 6 with pretibial myxedema and one patient with lichen myxedematosus. In all 31 specimens, mucin stained positive for Alcian blue and negative for PAS. In FM, mucin deposition was exclusively found in hair follicles and sebaceous glands. None of the other entities showed mucin deposits in follicular epithelial structures. Using MFS, all cases showed CD4+ and CD8+ T cells, tissue histiocytes, fibroblasts and pan-cytokeratin+ cells. These cells expressed MUC1 at different intensities. MUC1 expression in tissue histiocytes, fibroblasts, CD4+ and CD8+ T cells, and follicular epithelial cells of FM was significantly higher than the same cell types in the dermal mucinoses (p < 0.001). CD8+ T cells were significantly more involved in expression of MUC1 than all other analysed cell types in FM. This finding was also significant in comparison with dermal mucinoses. CONCLUSION: Various cell types seem to contribute to mucin production in PCM. Using MFS, we showed that CD8+ T cells seem to be more involved in the production of mucin in FM than in dermal mucinoses, which could indicate that mucin in dermal and follicular epithelial mucinoses have different origins.

Obesity-associated lymphedematous mucinosis and stasis mucinosis.

Cutaneous dermal mucinoses are a group of conditions characterized by abnormal deposition of mucin (hyaluronic acid and sulfated glycosaminoglycans) in the dermis. They can be classified either as localized or generalized forms and occur primarily or secondarily to systemic disorders. Obesity-associated lymphedematous mucinosis and pretibial stasis mucinosis are uncommon and relatively newly recognized disorders occurring in obese patients or in patients with venous insufficiency. Clinically, patients present with papules and nodules progressing to plaques and arising in an erythematous and edematous basis on the legs, especially the shins. Histopathologic examination indicates mucin deposition in the superficial portion of the dermis, angioplasia with an increase in small blood and/or lymphatic vessels, vertically running vessels, slight fibrosis, and no inflammation. Laboratory workup and histopathologic testing are helpful in differentiating these entities from pretibial myxedema (thyroid dermopathy), which represents the main differential diagnosis. Obesity-associated lymphedematous mucinosis and stasis mucinosis are not different entities but belong to a spectrum of mucinoses secondary to an increased body mass index, chronic lymphedema, and/or chronic venous insufficiency.

Acral persistent papular mucinosis: A case report and summary of 24 Japanese cases.

Acral persistent papular mucinosis is a rare subtype of localized lichen myxedematosus. We report a case of a 41-year-old woman with acral persistent papular mucinosis. She had a 5-year history of multiple, scattered, whitish papules, on the back of both hands, of 2-5 mm in diameter. Histopathological examination revealed a focal, fairly circumscribed area with sparse collagen fibers in the upper and middle dermis. The circumscribed area was positively stained with Alcian blue. The papules were clinically and histologically diagnosed as acral persistent papular mucinosis. We also summarized 24 Japanese acral persistent papular mucinosis cases, including ours. Although acral persistent papular mucinosis occurs predominantly in women according to overseas reports, the male : female ratio is 5:7 in Japan. It has been reported that tranilast (N-[3,4-dimethoxycinnamoyl]-anthranilic acid) was effective in two Japanese cases. In our case, the patient had been treated with tranilast for 2 months without improvement. Further studies are required to confirm the efficacy of tranilast for acral persistent papular mucinosis.