Merkel Cell Carcinoma Concurrent with Bowen's Disease

Abstract

Merkel cell carcinoma (MCC) is a rare, aggressive cutaneous malignancy of the elderly and immunocompromised patients. It is occasionally found coexisting with other diseases, such as squamous cell carcinoma, basal cell carcinoma, actinic keratosis, miscellaneous adnexal tumors, and rarely Bowen disease. A 75-year-old woman presented with a 6-month history of an irregularly shaped erythematous patch on the left mandibular angle. Three months later, a 1.5×1.0 cm sized painless and rapidly growing erythematous nodule developed on the patch. Microscopically, the patch lesion was consistent with that of Bowen disease. The nodular lesion showed a number of small uniform hyperchromatic cells with scanty cytoplasm. It showed dense small-cell like nodular infiltration in the dermis. Immunohistochemical staining for cytokeratin 20 showed a positive result with a dot-like perinuclear pattern. Additionally, the result for thyroid transcription factor-1 was negative, which is positive in small cell neuroendocrine carcinoma. From these findings, we diagnosed this lesion as MCC concurrent with Bowen disease.

Clinical features and outcomes of Merkel cell carcinoma in 20 cats

“…These findings suggest that in most of the cases the tumour cells were derived from Merkel cells of the hair follicle. The concomitant occurrence of MCC and other skin tumours (eg, SCC, Bowen's disease or BCC) has been reported in humans. In the present study, various degrees of irregular acanthosis and epidermal dysplasia were observed adjacent to the tumours in 9 cases (60%).…”

“…Immunosuppressed individuals are at higher risk of MCC . The concomitant occurrence of MCC and other skin tumours has also been reported …”

“…10,13 The concomitant occurrence of MCC and other skin tumours has also been reported. [14][15][16][17][18] In the 6 previously reported feline MCC cases, the tumours were surgically removed; however, only 1 cat survived for more than 2 years. [1][2][3][4] In humans, MCC is an aggressive tumour with a high recurrence rate and often metastasizes to the regional lymph nodes, 12,19 and 5-year overall survival rate of MCC patients is 40%.…”

Presence of the Merkel cell polyomavirus in Merkel cell carcinoma combined with squamous cell carcinoma in a patient with chronic arsenism

“…UV light is believed to be an important factor in the occurrence MCC concomitant with SCC . However, most cases of combined SCC and MCC affect primarily sun‐exposed areas of the skin, especially the face and neck in female patients . Our patient had MCC on her right breast, a sun‐spared area.…”

“…1 However, most cases of combined SCC and MCC affect primarily sun-exposed areas of the skin, especially the face and neck in female patients. [7][8][9] Our patient had MCC on her right breast, a sun-spared area. Ho et al 3 reviewed 10 patients from arsenic endemic areas, and suggested the arsenic-related combined SCC and MCC tends to occur in non-sun-exposed areas, making this entity clinically distinct from UV-related combined SCC and MCC.…”