Merkel Cell Carcinoma with Pagetoid Spread

Abstract

A case of Merkel cell carcinoma showing epidermotropism is presented. The neoplastic cells displayed dotlike immunoreactivity for cytokeratins and strong immunoreactivity for neuron-specific enolase. Although no neuroendocrine granules were found, characteristic paranuclear fibrous bodies were present.

Merkel cell carcinoma in organ‐transplant recipients: report of two cases with unusual histological features and literature review

“…MCC develop primarily in the dermis. An epidermotropic spread is found in 10–30% of cases, 25 occasionally with a pagetoid spread 38–40 or formation of Pautrier‐like microabscesses 41 . On very rare occasions, MCC is entirely confined to the epidermis 42 .…”

Merkel cell carcinoma in situ

“…MCC has been reported in association with solar keratosis, SCC in situ , SCC, follicular tumors, basal‐cell carcinoma, and lentigo maligna 9–18 . These tumors can occur before, after, simultaneously, or admixed with MCC.…”

“…Occasional cases report an epidermal component in excess of the dermal portion 8,18,19 . The epidermal involvement can appear as single cells or nests along or just above the basal layer, aggregates similar to Pautrier's microabscesses, or in a pagetoid pattern 4,9,14,18–21 . MCC should be included in the pagetoid differential diagnosis of mycosis fungoides, malignant melanoma, SCC, mammary and extramammary Paget's disease, porocarcinoma, sebaceous carcinoma, pagetoid reticulosis, and Langerhans' cell histiocytosis 4,18,19,21 .…”

Merkel Cell Hyperplasia Versus Intraepidermal Merkel Cell Carcinoma: A Comparative Study of 2 Cases

“…8 Epidermotropism of MCC has since been described in multiple case series and reports with consistent histopathologic and immunophenotypic features that suggest malignant behavior. [8][9][10][11][12][13] These histologic features include poorly nested or pagetoid basaloid cells within the epidermis, typically with numerous apoptoses and mitoses evident. 11,12 When the dermal components of these epidermotropic tumors were described, the findings were unsurprisingly similar to the intraepidermal components with descriptions of basaloid cells with scant cytoplasm and numerous mitotic figures and necrotic single cells evident.…”