Cutaneous focal mucinosis – a histopathological an immunohistochemical analysis of 11 cases

Abstract

The histogenesis of cutaneous focal mucinosis (CFM) is controversial. Eleven cases of CFM (5F, 6M; mean age 51 years) from our routine files between 1986 and the present time have, therefore, been examined histopathologically and immunohistochemically. Histology revealed an increased number of fibroblast-like cells in early lesions, whereas they were diminished or predominantly at the margin in advanced ones. The myxomatous areas showed slight to absent reticulum formation. Similarly, elastic fibers were almost absent, and collagen fibers were fragmented and replaced by variable amounts of mucin. One specimen revealed an epithelial component within the lesion reminiscent of a poorly induced trichofolliculoma. Immunohistochemically, vimentin was consistently present and correlated with the number of fibroblast-like cells. A few (< 5%) CD34+ dermal dendritic cells (DDs) were focally seen within CFM. In contrast, FXIIIa+ DDs accounted for up to 30%. Fibroblast-like cells were negative for S-100 protein, Leu7, desmin and alpha-SMA. The epithelial component within one of our specimens seems to have been induced by CFM and is a feature also seen in (angio)-myxomas. CFM appears to be a mesenchymally derived lesion composed predominantly of fibroblasts. DDs do not form the major cell component but rather seem passively incorporated.

Oral Focal Mucinosis- Presenting as conventional epulis with unconventional histopathology- Revealed by Special stains

“…CFM was described in 1966 by Johnson and Helwig for an asymptomatic, solitary growth which showed myxoid areas admixed with spindle shaped fibroblast [5] . They commonly occur on the face, trunk and extremities.…”

Angiomixoma cutáneo primario

“…La localización de estos tumores en la cabeza y el cuello corresponde al 17 % del total de la patología (11,12).…”

“…Otras referencias de la literatura (17)(18)(19) describen lesiones únicas o múl-tiples categorizadas como mucinosis cutánea focal, no siendo consideradas como verdaderos Mixomas. Se caracterizan por ser una acumulación local de material mucinoso en la dermis, con "scattered spindle cells" pero con menor vascularización que los Mixomas (11).…”

Oral Focal Mucinosis of the Tongue: A Rare Clinical Case

“…From a clinical point of view, the lesions appear as asymptomatic round swellings, usually of a similar color to the surrounding mucosa, with a preference for areas of adherent mucosa. The cutaneous lesions do not appear to associate to oral localizations (2). Histologically, the tissue sections present a well-defined area represented by an accumulation of hyaluronic acid in the inner connective tissue, surrounded by dense, but normal collagenous fibrous connective tissue.…”

“…The microscopic aspect of OFM represents therefore the only reliable diagnostic tool, though not free from interpretative difficulties: the histological images must be further investigated in order to exclude syndromic forms such as lupus erythematosus, infantile cutaneous mucinosis, lichen mixedematosus, the odontogenic myxoma and nerve sheath myxoma (I, 2,7,16,20). Hence, the rare manifestation of OFM should be carefully analysed in every aspect in order to formulate a certain diagnosis and to proceed with the conservative treatment of surgical removal of the lesion, which is necessary and sufficient for the healing of the area of interest avoiding pathological repetitions (7).…”