title: Horrifying Basal cell carcinoma: cytological, immunohistochemical, and ultrastructural findings.
abstract: Basal cell carcinoma (BCC) is a slow-growing and frequently occurring tumor of the eyelids. Among BCC cases, there is a subtype of aggressive cases called horrifying BCC (HBCC). There are also rare BCC cases that show neuroendocrine differentiation. Here, we describe a case of HBCC with neuroendocrine differentiation. The patient, a 41-year-old woman, presented with abnormal left eye tearing and left cheek pain. On computed tomography imaging, a tumor that extended to the left orbit was detected in the left cheek. On cytological examination of fine-needle aspiration (FNA) samples, the tumor cells were observed as sheet-like clusters and single bare nuclei with a clear background; peripheral palisading was not clearly seen. On examination of the biopsy specimen taken after FNA, the tumor was found to be composed of cancer cell nests with scattered peripheral palisading in the dermis. Immunohistochemically, the tumor cells were positive for cytokeratin (CK) 7 and CD56 and were negative for CK20, synaptophysin, and chromogranin A. Membrane-bound dense-core granules were detected on ultrastructural study. A HBCC case with neuroendocrine differentiation has not been previously reported. The correlation between the presence of neuroendocrine differentiation in HBCC and patient prognosis should be further studied.
authors.affiliation: Department of Pathology II, Kansai Medical University, Hirakata, Amagasaki, Japan ; Division of Diagnostic Cytopathology and Histopathology, Kansai Medical University Takii Hospital, Moriguchi, Amagasaki, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Kinoshita
authors.affiliation: Division of Surgical Pathology, Hyogo Prefectural Amagasaki Hospital, Amagasaki, Japan.
authors.forename: Kosho
authors.initials: K
authors.lastname: Takasu
authors.affiliation: Department of Pathology II, Kansai Medical University, Hirakata, Amagasaki, Japan.
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Yoshizawa
authors.affiliation: Department of Pathology II, Kansai Medical University, Hirakata, Amagasaki, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Emoto
authors.affiliation: Department of Pathology II, Kansai Medical University, Hirakata, Amagasaki, Japan.
authors.forename: Michiko
authors.initials: M
authors.lastname: Yuki
authors.affiliation: Department of Pathology II, Kansai Medical University, Hirakata, Amagasaki, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Yuri
authors.affiliation: Division of Diagnostic Cytopathology and Histopathology, Kansai Medical University Takii Hospital, Moriguchi, Amagasaki, Japan.
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Shikata
authors.affiliation: Department of Pathology II, Kansai Medical University, Hirakata, Amagasaki, Japan.
authors.forename: Airo
authors.initials: A
authors.lastname: Tsubura
keywords: Cytology; Electron microscopy; Horrifying basal cell carcinoma; Immunocytochemistry