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.

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.

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.

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.

Cutaneous mucinosis of infancy: a rare case of joint involvement.

BACKGROUND: Primary cutaneous mucinosis are a heterogeneous group of diseases characterized by the deposition of glycosaminoglycans in the dermis and the follicles. These diseases are rare in children therefore their diagnosis and management are still challenging. Joint involvement has been reported in patients with secondary cutaneous mucinosis and, rarely, in primary mucinosis. We describe a case of Cutaneous Mucinosis of Infancy with joint involvement. CASE PRESENTATION: An healthy 5-year-old boy showed acute arthritis of the left knee and left elbow confirmed by ultrasound. Laboratory tests were within normal range. Symptoms disappeared after a course of nonsteroid anti-inflammatory drugs. One year later, the knee swelling reappeared; juvenile idiopathic arthritis was diagnosed and intra-articular steroid injection was performed. Due to persistence of arthritis of the knee he was admitted to our hospital. On physical examination variable skin-colored lesions were observed, which had been in existence for over 2 years. We performed a skin biopsy that showed an interstitial mucine deposition in the reticular dermis. Cutaneous Mucinosis of Infancy was diagnosed. DISCUSSION AND CONCLUSIONS: Cutaneous Mucinosis of Infancy is a persistent dermatosis with benign prognosis and no treatment is generally required. Our case report is particularly interesting because it is the first in which joint involvement has been reported in CMI, a disorder that has so far been described as limited to skin involvement. Further studies will be necessary in order to clarify the pathogenesis of joint involvement in primary mucinosis.

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.

Oral focal mucinosis: A multi-institutional study and literature review.

BACKGROUND: Oral focal mucinosis (OFM) is a rare benign condition of unknown etiology, considered the oral counterpart of cutaneous focal mucinosis. We report the clinicopathologic features of 21 cases of OFM in conjunction with a review of the literature. METHODS: Clinical data were collected from the records of five oral and maxillofacial pathology services. All cases were evaluated by hematoxylin and eosin staining, histochemistry, and immunohistochemistry (vimentin, S-100, α-SMA, CD34, and mast cell). RESULTS: The series comprised 14 females (66.7%) and seven males (33.3%), with a mean age of 48.2 ± 20.7 years (range: 8-77 years) and a 2:1 female-to-male ratio. Most of the lesions affected the gingiva (n = 6, 28.6%) and presented clinically as asymptomatic sessile or pedunculated nodules with fibrous or hyperplasic appearance. All cases were negative for S-100 protein, CD34, and α-SMA and positive for Alcian blue staining. Conservative surgical excision was the treatment in all cases, and there was only one recurrence. CONCLUSION: OFM is a rare benign disorder that is often clinically misdiagnosed as reactive lesions or benign proliferative processes. Dermatologists and pathologists should consider OFM in the differential diagnosis of soft tissue lesions in the oral cavity, mainly located in the gingiva.

Plaque-like cutaneous mucinosis of childhood.

A healthy 10-year-old boy presented with plaque-like cutaneous mucinosis (PCM) on his back. Cutaneous biopsy was followed by progressive resolution of the skin lesion. Pediatric PCM could differ clinically from the adult form. However, more cases are necessary to draw conclusions.

[Cutaneous mucinosis of infancy]. / Kutane Muzinose der Kindheit.

Cutaneous mucinosis of infancy is a rare skin disease with just a few reported cases in the literature. We report the case of an 11-year-old boy with asymptomatic, skin-coloured papules and plaques on his right arm that had appeared 9 months prior to presentation. Histology showed a dermal and deep dermal interstitial mucin deposition and fibroblast proliferation. However, because cutaneous mucinosis of infancy is a benign disease with a good prognosis, therapy is not mandatory.