Nodular colloid degeneration of the skin: Report of three cases with review and update

Abstract

Nodular colloid degeneration (NCD) is a rare dermatological disorder and uncommon type of colloid milium. The degeneration may be related to sun exposure. In this report, three cases, all presenting as multiple plaques and nodules over the nose and the face are depicted. Histologically, these nodular masses were homogeneous, with eosinophilic-cleaved materials expanding the papillary dermis and extending into the deep dermis. Periodic acid Schiff (PAS), crystal violet, and methyl-violet stains highlight the colloid material. All the three cases were finally diagnosed as NCD. NCD could be considered in any case with facial nodules and a long history of sun exposure. We suggest the long-term sun exposure as an etiologic factor; thus sun protection would be the most preventive and available treatment.

Colloid milium, an expression of excessive sun exposure in Ecuadorian patients

“…Pigmented CM has been related to hydroquinone use, as our second case, and presents lesions resembling caviar‐like papules darker than the patient's normal skin along with atrophy . Finally, the nodular type or nodular colloid degeneration has solitary or multiples plaques or nodules of up to 5 cm with a slightly lumpy surface …”

“…It is considered a rare degenerative disease of unknown prevalence and origin, although it is believed that ultraviolet radiation is the most important triggering factor. UV exposure could cause degeneration of keratinocytes and elastic and collagen fibers with secondary accumulation of protein products and fibroblast secretions . Furthermore, it has been associated with hydroquinone use, ochronosis, trauma, chronic exposure to fertilizers, and petroleum products …”

“…CM is characterized by firm and waxy papules of each 5 mm that can be translucent, yellow‐brown or skin color, and develop slowly and symmetrically. It predominates in sun‐exposed areas such as cheeks, ears, nose, neck, and dorsum of hands; however, it has also been reported in unexposed sites such as trunk and penis . Four clinical forms are described: classic adult type, juvenile, pigmented, and nodular .…”

“…Histologically, it is characterized by accumulation of homogenous, amorphous, faintly eosinophilic material with cleft‐like spaces in papillary dermis, with a background of solar elastosis. CM stains positive with PAS and weakly with congo red but presents a negative reaction with alcian‐blue …”

Xanthoma‐like multiple yellowish nodular colloid degeneration on the face and scalp

“…or paracolloid is a rare subtype that presents as nodular, plaque-like lesions usually on chronically sun-exposed skin 1,2 . We present a case of nodular colloid degeneration or paracolloid that occurred on the face and scalp.…”