A Case of Canalicular Adenoma Arising on the Upper Lip / 대한피부과학회지

Canalicular adenoma is a rare benign tumor that arises in the minor salivary gland. Clinically, it usually presents as an asymptomatic nodule on the upper lip or buccal mucosa. It is necessary to histopathologically differentiate canalicular adenoma from basal cell adenoma and adenoid cystic carcinoma. Canalicular adenoma shows tubular structures composed of 1 or 2 layers of columnar cells and intraluminal hemorrhage. Squamous morules, which seem to represent metaplasia, are a unique finding for this tumor. Immunohistochemical staining is often helpful for the diagnosis of canalicular adenoma, which is positive for S-100 and CK (AE1/3). Herein, we report a case of canalicular adenoma in a 71-year-old man who presented with an asymptomatic nodule on the upper lip. As far as we know, this is the first report of canalicular in Korean Dermatology Journal.

The Usefulness of Immunocytochemistry of CD56 in Determining Malignancy from Indeterminate Thyroid Fine-Needle Aspiration Cytology

BACKGROUND: Fine-needle aspiration cytology serves as a safe, economical tool in evaluating thyroid nodules. However, about 30% of the samples are categorized as indeterminate. Hence, many immunocytochemistry markers have been studied, but there has not been a single outstanding marker. We studied the efficacy of CD56 with human bone marrow endothelial cell marker-1 (HBME-1) in diagnosis in the Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) category III. METHODS: We reviewed ThinPrep liquid-based cytology (LBC) samples with Papanicolaou stain from July 1 to December 31, 2016 (2,195 cases) and selected TBSRTC category III cases (n = 363). Twenty-six cases were histologically confirmed as benign (six cases, 23%) or malignant (20 cases, 77%); we stained 26 LBC slides with HBME-1 and CD56 through the cell transfer method. For evaluation of reactivity of immunocytochemistry, we chose atypical follicular cell clusters. RESULTS: CD56 was not reactive in 18 of 20 cases (90%) of malignant nodules and showed cytoplasmic positivity in five of six cases (83%) of benign nodules. CD56 showed high sensitivity (90.0%) and relatively low specificity (83.3%) in detecting malignancy (p = .004). HBME-1 was reactive in 17 of 20 cases (85%) of malignant nodules and was not reactive in five of six cases (83%) of benign nodules. HBME-1 showed slightly lower sensitivity (85.0%) than CD56. The specificity in detecting malignancy by HBME-1 was similar to that of CD56 (83.3%, p = .008). CD56 and HBME-1 tests combined showed lower sensitivity (75.0% vs 90%) and higher specificity (93.8% vs 83.3%) in detecting malignancy compared to using CD56 alone. CONCLUSIONS: Using CD56 alone showed relatively low specificity despite high sensitivity for detecting malignancy. Combining CD56 with HBME-1 could increase the specificity. Thus, we suggest that CD56 could be a useful preoperative marker for differential diagnosis of TBSRTC category III samples.

A Rare Case of Aggressive Melanotic Schwannoma Occurred in Spinal Nerve of a 59-Year-Old Male

Melanotic schwannoma (MS) is a rare variant of nerve sheath neoplasm that shows ultrastructural and immunophenotypical features of Schwann cells but also has cytoplasmic melanosomes and is reactive for melanocytic markers as well. Unlike conventional schwannoma, which is totally benign, MS has an unpredictable prognosis and is thought to have low-malignant potential. Herein, we present a rare case of recurrent MS in lumbar spine of a 59-year-old male.