Primary localized cutaneous lichen myxedematosus with light chain-restricted plasma cells: A distinct variant of the localized form of lichen myxedematosus.

Lichen myxedematosus (LM) is a chronic cutaneous mucinosis that can present as a localized skin lesion or as a generalized systemic disease termed scleromyxedema. The differential diagnosis is determined by a combination of clinical presentation, serological studies, and histopathological examination. Currently, well-established and accepted histopathological features to distinguish localized LM from scleromyxedema have not been elucidated. Our recent publication, together with a retrospective literature review, suggests that the presence of groups of light chain-restricted plasma cells represents a distinct histopathological clue for the diagnosis of localized LM. In this report, we provide two additional cases of localized LM with lambda light chain-restricted plasma cells, together with clinical and histopathological findings that are similar to our previous publication. These cases support our theory that the light chain-restricted plasmacytic microenvironment is primarily attributed to the pathogenesis of localized LM. Therefore, we consider these cases to constitute a clinically and pathologically new variant of localized LM and name it primary localized cutaneous LM with light chain-restricted plasma cells.

Reticular erythematous mucinosis: Literature review and case report of a 24-year-old patient with systemic erythematosus lupus.

Reticular erythematous mucinosis (REM) was first described 50 years ago, but only around 100 case reports in English have been published. Its relation with other inflammatory skin disorders is still being debated. We report a case of REM, including the clinical and histopathological findings. Also, a systematic review of 94 English-language reported cases is provided. The described criteria for clinical and histopathological diagnosis are highlighted in order to REM can be confidently diagnosed.

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.

Clinical and Histopathological Features of Scleroderma-like Disorders: An Update.

Scleroderma-like disorders include a set of entities involving cutis, subcutis and, sometimes, even muscular tissue, caused by several pathogenetic mechanisms responsible for different clinical-pathological pictures. The absence of antinuclear antibodies (ANA), Raynaud's phenomenon and capillaroscopic anomalies constitutes an important element of differential diagnosis with systemic sclerosis. When scleroderma can be excluded, on the basis of the main body sites, clinical evolution, any associated pathological conditions and specific histological features, it is possible to make a correct diagnosis.

Self-healing juvenile cutaneous mucinosis, a sclerodermoid disorder simulating juvenile dermatomyositis: a case-based review.

Self-healing juvenile cutaneous mucinosis (SHJCM) is a rare childhood disease with characteristic cutaneous and rheumatic manifestations. Cutaneous manifestations include a combination of nodules affecting peri-articular (especially interphalangeal joints) and head and neck areas; and linearly arranged ivory white papules over an erythematous indurated skin. Despite a benign course, an abrupt onset of symptoms with extensive cutaneous involvement often leads to parental anxiety, overenthusiastic evaluation and sometimes aggressive treatment. A peculiar cutaneous distribution in SHJCM including nodular lesions and periorbital edema, arthritis and arthralgia in a few cases, may simulate juvenile dermatomyositis. It is, therefore, important for dermatologists and pediatricians to be aware of this entity. In this report, we describe two cases of SHJCM and briefly review similarly reported cases in children.

Scleromyxedema in a 21 year old female patient with acute lymphoblastic leukemia: a case report.

BACKGROUND: Scleromyxedema is a rare, para-neoplastic, chronic, progressive condition of the Lichen myxedematosus (LM) family. The clinical picture consists of generalized confluent papular eruptions with possible systemic manifestations, which may be fatal as it still constitutes a therapeutic dilemma. Histologically, it is characterized by dermal mucin deposition, fibroblast proliferation with fibrosis, with monoclonal gammopathy in the absence of thyroid disease. Some atypical forms of the disease were reported in the literature, but none were reported in acute leukemia. CASE PRESENTATION: Herein, we report a case of a 21 years old female patient, known case of acute lymphoblastic leukemia (ALL), who developed numerous hyper-pigmented erythematous papules and plaques, mainly over her thighs, lower abdomen, and sub-mammary flexures. Histopathology of skin lesions confirmed the diagnosis of atypical scleromyxedema. Her symptoms significantly improved with the use of high dose intravenous immunoglobulin (IVIG). CONCLUSIONS: Despite that scleromyxedema is associated with many hematologic disorders, it is very rarely associated with acute lymphoblastic leukemia, and a high index of suspicion is needed for diagnosis. IVIG remains a reasonable management of such a disabling disease.

[Reticular erythematous mucinosis-A special subtype of cutaneous lupus erythematosus?] / Retikuläre erythematöse Muzinose ­ Sonderform eines kutanen Lupus erythematodes?

Reticular erythematous mucinosis (REM syndrome) is a rare skin disease that predominantly affects women. It is clinically characterized by flat, partly reticular, irregularly configurated pale erythema located in the region of the central chest and upper back. The skin alterations are usually asymptomatic or associated with slight pruritus or burning. Extracutaneous diseases and involvement of internal organs do not occur in REM syndrome. Histopathological features include perivascular and periadnexal lymphocytic inflammatory infiltrates as well as increased deposition of mucin in the dermis. Due to the similar histology to lupus erythematosus (LE) tumidus, it is discussed whether REM syndrome can be assigned to the spectrum of cutaneous LE or can be assessed as a lupus-like disease. Moreover, both conditions respond well to treatment with hydroxychloroquine.

[A case of "juvenile" self-healing cutaneous mucinosis in an adult]. / Mucinose cutanée « juvénile ¼ auto-involutive chez l'adulte.

INTRODUCTION: Self-healing juvenile cutaneous mucinosis (SHJCM) is a stereotypical disease in children characterized by the acute onset of subcutaneous papules and nodules on the face, dorsum of the hands and peri-articular regions that disappear spontaneously within a few months or years. A few cases have been reported in adults, but these display more heterogeneous clinical and histopathological features. Herein we report a case with a juvenile clinical presentation in an adult woman. OBSERVATION: A 36-year-old patient with a history of Von Willebrand disease was referred to our dermatology department following the rapid development of subcutaneous nodules on her face, hands and large joints, together with periorbital edema. Three nodules were surgically removed and histology demonstrated mucin deposition in the dermis with dissociation of collagen fibers. Autoimmune disease, neoplasia, infection and dysthyroidism were ruled out. Bilateral carpal tunnel syndrome was confirmed by electromyogram in this patient carrying out manual work. Treatment with hydroxychloroquine proved unfruitful. After 1.5 years of follow-up, her lesions showed partial regression. CONCLUSION: The form of SHJCM described in pediatric populations may occur in rare cases in adults. Should the name of juvenile mucinosis still be used in this event?

Oral focal mucinosis in adolesence: a sparingly diagnosed clinicopathologic entity.

OBJECTIVE: Oral focal mucinosis an oral counterpart of cutaneous focal mucinosis, is a rare disease of unknown etiology. Its pathogenesis may be due to the overproduction of hyaluronic acid by a fibroblast, at the expense of collagen production, resulting in focal myxoid degeneration of the connective tissue, primarily affecting the mucosa overlying the bone. Oral focal mucinosis occurs predonderantly in adults during the fourth and fifth decade of life, although it has been reported sparingly in children and adolescents. It has no distinctive clinical features, as the diagnosis is solely based on the histopathological features and treatment involves complete surgical excision. Recurrence is unreported. This case report put forward the clinical and histological presentation and consequent management of Oral focal mucinosis in an adolescent female patient.

Follicular mucinosis in patients with hematologic malignancies other than mycosis fungoides: A clinicopathologic study.

BACKGROUND: Follicular mucinosis (FM), which is defined by mucin accumulation within follicular epithelium, may occur in mycosis fungoides (MF). FM without MF is occasionally reported in systemic hematologic malignancies and may be diagnostically challenging. OBJECTIVE: To describe clinicopathologic characteristics of FM in patients with hematologic malignancies other than MF. METHODS: Clinical data and histopathology features were analyzed in patients with FM and hematologic malignancies diagnosed between 1994 and 2017. RESULTS: A total of 18 patients with FM and systemic hematologic malignancies without cutaneous T-cell lymphoma (CTCL) were identified; 9 of them were discovered after hematopoietic stem cell transplantation. No patients with non-CTCL-associated FM (n = 46 [37 biopsy specimens]) developed CTCL during a mean follow-up of 4.3 years. Of the cases of CTCL associated with FM (n = 44 [31 biopsy specimens]), MF was the most common subtype (n = 38), although other CTCLs were identified. FM in patients with non-CTCL hematologic malignancies differed clinically from those with MF-associated FM, presenting most frequently with erythematous papules (P < .0001), without plaques (P <.0001), without alopecia (P = .001), and without histopathologically identified epidermal exocytosis (P = .013). LIMITATIONS: A retrospective study in a single cancer center. CONCLUSIONS: FM can present in systemic hematologic malignancies, including after hematopoietic stem cell transplantation. Papular lesional morphologic and histopathologic features may help to distinguish these cases from MF.

Follicular induction and CK20+ Merkel cells overlying cutaneous focal mucinosis.

BACKGROUND: Cutaneous focal mucinosis (CFM) or focal dermal mucinosis is a benign reactive process categorized as a primary mucinosis. Skin biopsy is essential for diagnosis, as the clinical appearance is often non-specific. Follicular induction is a phenomenon whereby the epidermis is induced by an underlying process to form primitive or mature hair follicles, and is commonly seen overlying dermatofibromas. Follicular induction has been rarely described in CFM. METHODS: We performed a retrospective histological review of lesions of CFM confirmed by skin biopsy from 2010 to 2015 in our department. RESULTS: We found that 11% (11/98) of CFM lesions showed follicular induction. Cytokeratin 20 (CK20) immunostaining was performed on all 11 of these biopsies that showed follicular induction and highlighted an increased density of CK20+ Merkel cells within the basaloid epidermal proliferations. CONCLUSION: As superficial basal cell carcinomas (BCC) often show a mucinous stroma around the basaloid islands, CFM with follicular induction may closely mimic a BCC histologically, particularly in superficial shave biopsies. Therefore, it is important that dermatopathologists be aware of this phenomenon. Furthermore, CK20+ staining within the basaloid epithelial proliferations may be helpful in differentiating CFM with follicular induction from a BCC.

Self-healing juvenile cutaneous mucinosis: Clinical and histopathologic findings of 9 patients: The relevance of long-term follow-up.

BACKGROUND: Self-healing juvenile cutaneous mucinosis (SHJCM) is a rare disorder, and its pathogenesis and long-term prognosis are unknown. OBJECTIVE: To elucidate the clinical and histopathologic characteristics, pathogenesis, and outcome in patients with SHJCM. METHODS: Retrospective study of 9 patients with SHCJM. To complement initial findings, data collection forms were sent to the referring physicians. RESULTS: All patients had an acute onset of firm nodules. Of the 9 patients, 6 presented initially with waxy papules on the dorsum of the hands; 5 suffered from periorbital edema, and 6 had a febrile prodrome. Histopathologic assessment of the papules revealed dermal mucin deposition, whereas the nodules showed proliferative fasciitis-like features or nonspecific chronic lobular panniculitis. Laboratory studies elicited evidence of active viral infection in 2 patients (human herpes virus 6 and rotavirus). Seven cases had spontaneous resolution within 6 months, and 2 patients with incomplete resolution showed subsequent transition to fibroblastic rheumatism and an autoinflammatory rheumatologic disease, respectively. LIMITATIONS: This was a retrospective study with incomplete data from referring physicians. CONCLUSIONS: Although spontaneous complete regression is expected, patients with SHJCM need long-term follow-up because of the possible development of dematorheumatolgic conditions. The pathogenetic role of microbial agents deserves further investigation.

Review of Primary Cutaneous Mucinoses in Nonlupus Connective Tissue Diseases.

Lichen myxedematosus is an idiopathic, cutaneous mucinosis with 2 clinicopathologic subsets. There is the generalised papular and sclerodermoid form, more properly termed scleromyxedema, and the localised papular form. We report the first case, to our knowledge, of lichen myxedematosus in association with rheumatoid arthritis as well as a case in association with dermatomyositis. An up-to-date literature review on cutaneous mucinoses and connective tissue diseases, excluding the common association of primary and secondary mucinoses with systemic lupus erythematosus, was also performed.

[Scleromyxedema]. / Skleromyxödem.

Scleromyxedema is a rare disorder that frequently affects multiple extracutaneous organ systems and is usually associated with monoclonal gammopathy. The pathogenesis of scleromyxedema is unknown. The clinical course is chronic and progressive and can lead to marked morbidity or death. The skin findings consist of multiple waxy papules and indurated plaques. Progressive skin involvement can lead to decreased mobility of the mouth and joints. Extracutaneous manifestations occur in the musculoskeletal or cardiovascular system, in the gastrointestinal or respiratory tract, or in the kidneys. There are no approved or evidence-based treatment options available for scleromyxedema. High-dose immunoglobulins are considered the treatment of choice, followed by lenalidomide (or thalidomide) and systemic glucocorticosteroids, or in severe cases even autologous hematopoetic stem cell transplantation. Long-term maintenance treatment is usually required and close clinical follow-up is necessary as recurrence of scleromyxedema is common after withdrawal of an effective therapy.

Follicular lymphomatoid papulosis with follicular mucinosis: a clinicopathologic study of 3 cases with literature review and conceptual reappraisal.

Lymphomatoid papulosis (LyP), characterized by recurring, waxing and waning, cutaneous papulonodules, is increasingly recognized to represent a heterogeneous collection of pathologically dissimilar subtypes. Recently, a follicular LyP variant was proposed, featuring folliculotropism. Folliculotropism by atypical lymphocytes is conventionally associated with follicular mucinosis and mycosis fungoides (MF), and review of the literature suggests co-occurrence of folliculotropism and follicular mucinosis in LyP to be rare, with only 3 cases identified to date. Herein we describe 3 additional cases, each manifesting a typical LyP clinical picture, with the additional element of folliculotropism and follicular mucinosis on pathology. These cases suggest that LyP should be considered alongside MF in the differential diagnosis of follicular mucinosis with accompanying atypical lymphocytic infiltration. As LyP can occur with other lymphoproliferative disorders such as MF, the finding of follicular mucinosis in LyP may further represent a conceptual intersection between the 2 disease processes.

Papulonodular mucinosis, Guillain-Barré syndrome and nephrotic syndrome in a patient with systemic lupus erythematosus: a case report.

BACKGROUND: Awareness of the spectrum of clinical manifestations of systemic lupus erythematosus (SLE), especially uncommon changes, is essential for diagnosis and effective management of patients. CASE PRESENTATION: A 26-year-old Chinese man with SLE initially manifested cutaneous papulonodular mucinosis and developed acute Guillain-Barré syndrome and class V lupus nephritis 2 years later. His cutaneous nodules had not been idententified for 2 years and were resected by surgical procedures twice until SLE was diagnosed. The kidney biopsy revealed class V lupus nephritis. The patient responded well to a short course of intravenous immunoglobulins and his muscle strength almost completely recovered. So far, he has undergone five cycles of cyclophosphamide combined with hydroxychloroquine and tapering prednisone, resulting in partial remission of lupus nephritis and disappearance of hypocomplementemia. CONCLUSION: We reported a rare case of male patient with SLE with manifestation of class V lupus nephritis, Guillain-Barré syndrome and papulonodular mucinosis.