A new case of syringocystadenocarcinoma papilliferum: a rare pathology for a wide-ranging comprehension

Abstract

We report a new case of p63/cytokeratin 7 (CK7) positive syringocystadenocarcinoma papilliferum (SCACP), on the shoulder of an 88-year-old man, with superficial dermal infiltration and squamoid differentiation. We describe the 24th case of SCACP, the malignant counterpart of syringocystadenoma papilliferum (SCAP). At the present, we do not know whether SCACP arises from eccrine or apocrine glands because of the contrasting opinions in the literature. Only few histochemical and ultrastructural studies have previously advised that SCACP could arise from pluripotent stem cells. Through our case, we wish to suggest the stem cell-like properties of the syringocystadenocarcinoma papilliferum. This rare neoplasm shows two different patterns of stem cell marker expression in the glandular and squamous components, respectively. For the double phenotype of SCACP, we propose it like an intriguing model to study histogenesis and stem cell properties for more wide-ranging epithelial tumors.

Figure 1

Analysis of a skin syringocystadenocarcinoma papilliferum specimen. (a) Specimen shows squamous cancer cells in the dermis gradually deepening. The squamous budding generates internal cavities giving rise to glandular papillary structures (hematoxylin-eosin [H&E], original magnification ×40). (b) Note the adenopapillary infiltrative structures ([H&E], original magnification ×100). (c) Immunohistochemical staining demonstrates CK7 at the glandular budding forming the papillary components (original magnification ×40). (d) The squamous solid neoplasia persists negative for CK7 (original magnification ×100).

Figure 2

Analysis of a skin syringocystadenocarcinoma papilliferum specimen. (a) p63 antibody stains the transition area from epidermis epithelium to the squamous neoplasm and the basal layer of glandular component (original magnification ×40). (b) The papillary structures are moderately positive and/or negative for p63 (original magnification ×100). (c) Immunohistochemical staining demonstrates c-kit at the basal layer of neoplastic budding; almost negative, only with speckled positive cells, is the squamous solid component (original magnification ×20). (d) A few positive cells of the squamous neoplasia are stained by Nestin antibody, stemness marker (original magnification ×400).

Figure 3

Fluorescence microscopy analysis of the staminal property of syringocystadenocarcinoma papilliferum. Immunofluorescent staining demonstrates anti-CD133 (in red) and anti-CD44 (in green) antibodies; the nuclei are contrasted by DAPI (in blue). (a) The tumoral squamous portion shows membranous CD44 overexpression (original magnification ×200). (b) The transition area presents squamous budding with decreasing of CD44 positivity but increasing of nuclear-cytoplasmic CD133 expression (original magnification ×200). (c) Bifront-like staining showing CD44 more represented in the squamous area and CD133 stronger in the papillary component (original magnification ×200). (d) Overview of CD133 positive-cystic and papillary structures (original magnification ×100).