Basal Cell Carcinoma with Matrical Differentiation

Basal cell carcinoma: biology, morphology and clinical implications

“…45 Mitoses, apoptic cells and high-grade nuclear atypia are absent. 44 The term 'follicular squamous cell carcinoma' has been used to describe squamous cell carcinoma arising in the wall of an epidermal cyst; BCC arising in this setting is a rare event but is not unique to our experience (personal observation).…”

“…[44][45][46][47] The shadow cells have an anucleate morphology and eosinophilic cytoplasms often accompanied by zones of calcification. 45 Mitoses, apoptic cells and high-grade nuclear atypia are absent.…”

“…It is the more differentiated BCCs, such as the BCC with abortive hair papilla formation, and the infundibulocystic BCC which can cause confusion with respect to trichoepithelioma. 105 Immunostains can be helpful, such as CD34 that is expressed in the stroma of trichoepitheliomas but not that of BCCs, 44,106 and bcl-2, expressed diffusely in the indolent growth BCC but only around the periphery of a trichoepithelioma. 107 Trichofolliculoma, on the other hand, manifests a central keratin-filled pore containing hair shaft material, from which radiate squamoid bands that in turn connect to basaloid islands recapitulating follicular differentiation.…”

“…These include, but are not restricted, to keratotic BCC, 39 infundibulocystic BCC (Figure 12), 42,43 follicular BCC, [44][45][46][47] which shows collision features with pilomatricoma, pleomorphic BCC ( Figure 13), 48,49 BCC with eccrine differentiation, [50][51][52] BCC with sebaceous differentiation, the fibroepithelioma of Pinkus (Figure 14), 53 and the BCC with myoepithelial differentiation. 54 Keratotic BCC Also known as pilar BCC as it appears to differentiate along pilosebaceous lines, the keratotic BCC manifests large basaloid tumor nests that are rounded and show central keratinization and degeneration.…”

Melanocytic matricoma: an additional case with literature review over this rare entity

“…Finally, one of the most important differential diagnoses to be ruled out is basal cell carcinomas with matrical differentiation, which presents as a slowly growing ulcerated nodule, commonly in elderly men. Histopathological features of basal cell carcinoma with matrical differentiation include infiltrative tumour aggregates, peripheral nuclear palisading, and retraction clefts [12,[41][42][43][44][45][46][47] . Moreover, basal cell carcinomas with matrical differentiation shows positivity towards Ber-EP4 [1,2,34] and a focal and membranous pattern [44,46] of staining with beta-catenin, in contrast to melanocytic matricomas, which is negative to Ber-EP4 [4,7,11] and show an intense, pattern of nuclear and cytoplasmic positivity to beta-catenin [9,11,18] .…”