Adult variant of self-healing papular mucinosis in a patient with rheumatoid arthritis: predominant proliferation of dermal dendritic cells expressing CD34 or factor XIIIa in association with dermal deposition of mucin

Conjunctival Myxoid Lesions: Clinical-Pathologic Multiparametric Analysis, Including Molecular Genetics (An American Ophthalmological Society Thesis)

PURPOSE

To evaluate the clinical and pathologic characteristics of conjunctival myxoid lesions, with specific focus on PRKAR1A studies, in order to distinguish neoplastic conjunctival myxoma from other myxoid conjunctival lesions.

METHODS

A retrospective, interventional, multicenter study of all patients with conjunctival myxoma, conjunctival stromal tumor, or reactive fibromyxoid proliferation diagnosed during 1988-2018. Patient and family medical histories and clinical and pathologic characteristics of excised lesions were assessed.

RESULTS

There were 28 patients with conjunctival myxoid lesions diagnosed as myxoma (16/28), conjunctival stromal tumor (10/28), or reactive fibromyxoid proliferation (2/28). The patients with abundant myxoid matrix lesions (14/28, 50%) were younger (mean 49 [range 23-68] years) than those with scant-to-moderate myxoid matrix lesions (14/28, mean 61 [range 18-82] years; P = .04). Abundant myxoid matrix lesions more likely contained predominantly stellate cells (6/14 [43%] vs 0/14 [0%]; P = .05) and fibrillar collagen (13/14 [93%] vs 2/14 [14%]; P < .0001), conforming to the standard morphologic definition of myxoma. Absence of PRKAR1A protein expression was found in 2 lesions with morphologic features of myxoma (2/14, 14%), 1 of which demonstrated a pathogenic mutation in the PRKAR1A gene. There was no difference between the lesions with respect to other clinical and pathologic parameters.

CONCLUSIONS

PRKAR1A plays a role in the development of a subset of conjunctival myxomas, particularly in tumors fulfilling stringent morphologic criteria for myxoma. With the exception of PRKAR1A studies, current immunohistochemical panels cannot reliably distinguish between neoplastic conjunctival myxomas and other myxoid lesions, underscoring the importance of morphology in establishing accurate diagnosis.

Discrete Papular Lichen Myxedematosus and Scleromyxedema with Hypothyroidism: A Report of Two Cases

Scleromyxedema and lichen myxedematosus (LM) are rare disorders that fall along the spectrum of primary cutaneous mucinoses. Scleromyxedema is a systemic form that classically presents with generalized waxy papules, sclerodermoid eruption, and monoclonal gammopathy; LM is a localized form limited to the skin that classically presents with white, firm, waxy papules and lacks monoclonal gammopathy. According to diagnostic criteria established in 2001, the diagnosis of both conditions requires absence of thyroid disease. However, atypical cases that lack monoclonal gammopathy and that present with hypothyroidism have been reported, suggesting that these criteria may require revision. First, we report a case of a 58-year-old female with a history of Hashimoto thyroiditis and biopsy-proven scleromyxedema responsive to intravenous immunoglobulin therapy with delayed presentation of monoclonal gammopathy. Next, we report a case of a 54-year-old female with a history of hypothyroidism, Hodgkin's lymphoma in remission after radiation and chemotherapy, and concurrent rheumatoid arthritis, with biopsy-proven LM temporarily responsive to systemic steroids. Our cases demonstrate that patients with papular mucinoses can have a multitude of concurrent and prior rheumatologic and endocrine conditions, including thyroid disease, which should not preclude a diagnosis of scleromyxedema and LM.

Self-healing Cutaneous Mucinosis in Adulthood: The Adult Counterpart of the Juvenile Variant of the Disease?

Self-healing cutaneous mucinosis (SHCM) is an idiopathic localized cutaneous mucinosis mainly described in children and characterized clinically by an acute onset of papules and nodules that exhibit a spontaneous resolution in a period ranging from weeks to few months. Histologically, a diffuse mucin deposition in the dermis and/or hypodermis associated with a proliferation of spindle-shaped cells and some large epithelioid gangliocyte-like mononuclear cells is usually observed. An uncommon adult variant of SHCM has also been reported; however, the clinicopathological features described in these patients are extremely heterogeneous and differ significantly from the juvenile variant of the disease, often showing exclusively dermal involvement. We report a case of a 37-year-old female patient with multiple asymptomatic nodules located on the legs and arms that resolved spontaneously in a period of 2 years, showing the typical subcutaneous features of the juvenile variant of SHCM at the histological examination (ie, mucinous areas associated with dense bands of fibrosis containing arborizing thin-walled vessels, spindle-shaped fibroblasts, and some gangliocyte-like cells). To the best of our knowledge, this is the first report of SHCM showing the classic pattern of deep-seated subcutaneous involvement of the disease in an adult patient. We also review the cases of adult-onset SHCM reported in the literature.

Factor XIII Subunit A in the Skin: Applications in Diagnosis and Treatment

The role of factor XIII subunit A (FXIII-A) is not restricted to hemostasis. FXIII-A is also present intracellularly in several human cells and serves as a diagnostic marker in a wide range of dermatological diseases from inflammatory conditions to malignancies. In this review, we provide a guide on the still controversial interpretation of dermal cell types expressing FXIII-A and assess the previously described mechanisms behind their accumulation under physiological and pathological conditions of the human skin. We summarize the intracellular functions of FXIII-A as well as its possible sources in the extracellular space of the dermis with a focus on its relevance to skin homeostasis and disease pathogenesis. Finally, the potential role of FXIII-A in wound healing, as a field with long-term therapeutic implications, is also discussed.

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.

CD34+ dermal dendritic cells and mucin deposition in dermatomyositis

Dermal mucinosis is often associated with collagen diseases such as rheumatoid arthritis, lupus erythematosus, and dermatomyositis, in addition to autoimmune thyroiditis. We report eight cases of dermal mucin deposition secondary to typical dermatomyositis with cutaneous lesions known as heliotrope rash and Gottron’s papules. Striking mucin deposition was observed in both the papillary dermis and reticular dermis of all biopsy specimens. Immunohistochemical analysis showed that CD34+ dermal dendritic cells (DDCs) in the perilesional area in combination with vimentin+ cells within the mucinous lesion might be important in giving rise to abnormal deposition of dermal mucin. On the other hand, numbers of factor XIIIa+ DDCs and tryptase+ mast cells were reduced within and surrounding the mucin deposition, as compared with those in the dermis of normal controls. A pathogenic mechanism of dermal mucin deposition is proposed.

Extracorporeal Shock Wave Therapy: An Emerging Treatment Modality for Retracting Scars of the Hands

Prolonged and abnormal scarring after trauma, burns and surgical procedures often results in a pathologic scar. We evaluated the efficacy of unfocused shock wave treatment, alone or in combination with manual therapy, on retracting scars on the hands. Scar appearance was assessed by means of the modified Vancouver Scar Scale; functional hand mobility was evaluated using a range-of-motion scale, whereas a visual analogue score was implemented for detecting any improvements in referred pain. Additionally, biopsy specimens were collected for clinico-pathologic correlation. For each active treatment group, statistically significant improvements in modified Vancouver Scar Scale were recorded as early as five treatment sessions and confirmed 2 wk after the last treatment session. Analogous results were observed when assessing pain and range of movement. Histopathological examination revealed significant increases in dermal fibroblasts in each active treatment group, as well as in neoangiogenetic response and type-I collagen concentration.

Cutaneous manifestations associated with rheumatoid arthritis

Rheumatoid arthritis presents various cutaneous manifestations, either specific or nonspecific skin features, which are induced by the activation of inflammatory cells (neutrophils, lymphocytes, macrophages), vasculopathy, vasculitis, acral deformity, drugs, and so on. These include (1) specific findings, (2) findings due to vascular impairment, (3) findings due to immune dysfunction, (4) characteristic neutrophilic conditions, and (5) miscellaneous conditions. On the other hand, some of the specific manifestations show common histopathological features such as palisading granulomas with necrobiosis. It is important to recognize the common and/or uncommon skin conditions of RA for all clinicians associated with RA therapy.

Spontaneous resolution of facial papular mucinosis in a transplant patient

A 37-year-old male developed facial papules 6 months post renal-pancreatic transplant. Histological findings were consistent with localized papular mucinosis; electrophoresis showed no paraprotein. A trial of erbium and aura lasers, at ablative doses, produced no improvement. Independent treatments with oral doxycycline, itraconazole, acitretin, and isotretinoin also had no effect. The facial papules improved spontaneously, 2 years after first presentation and 8 months after treatment ceased. The patient remains clear of lesions.

Cutaneous mucinous nodule in a patient with rheumatoid arthritis

We report a cutaneous mucinous nodule on the inflamed elbow joint in a patient with rheumatoid arthritis (RA). The lesion is clinically characterized by a continuous flow of mucinous exudates from the nodule, and histologically by an extensive mucin deposition and proliferations of the fibroblastic cells and mononuclear cells. The histological findings suggest the histogenesis of this unique nodule is related to extralesional proliferation of synovial lining cells consisting of monocyte-macrophage lineage cells and fibroblast-like cells which potentially produce synovial fluid. Four patients have been hitherto reported in the published work and all of them have been associated with RA. The condition may be one of the characteristic skin manifestations of RA.