Background/Aims: Besifovir dipivoxil maleate (BSV) and tenofovir alafenamide fumarate (TAF) have been recently approved in Korea as the initial antiviral agents for chronic hepatitis B (CHB).However, the real-world outcome data for these drugs remain limited. Therefore, we conducted a noninferiority analysis using real-world data to compare the clinical outcomes of the two nucleotide analogs in treatment-naïve patients with CHB. Methods: We retrospectively investigated a cohort of patients with CHB who received BSV or TAF as first-line antiviral agents. The endpoints were virological response (VR) and liver-related clinical outcomes. Results: A total of 537 patients, consisting of 202 and 335 patients administered BSV and TAF, respectively, were followed up for 42 months. No significant difference was observed between the VRs of the patients from the two groups. The rates of biochemical response, virologic breakthrough, and incidence rates of hepatocellular carcinoma did not differ between the groups. However, the hepatitis B e antigen seroclearance rate was higher and the renal function declined less in the BSV group. Multivariable analysis indicated older age, alcohol abuse, cirrhosis and ascites, and lower serum HBV DNA level to be independently associated with increased hepatocellular carcinoma risk. The 1:1 propensity score-matched analysis with 400 patients showed VR rates of 85.0% and 88.7% in the BSV and TAF group patients, respectively, at 2 years. The absolute value of the 95% confidence interval for the difference (–0.04 to 0.12) satisfied the a priori limit of a noninferiority of 0.15. Conclusions BSV is noninferior to TAF in terms of VR, and their clinical outcomes are comparable to CHB.

Cutaneous collagenous vasculopathy (CCV) was first suggested by Salama and Rosenthal in 2000. CCV is characterized by blanching erythematous macules with telangiectasia, which begins on both lower legs and spreads to the trunk and upper extremities. A 23-year-old male visited our clinic presenting with diffuse blanching and confluent erythematous patches with telangiectasia on both lower legs and thighs with a burning sensation. The skin lesions had progressed in a spreading pattern 5 years ago. On histopathologic examination, dilated blood vessels with thick walls and perivascular amorphous material were observed in the superficial dermis. Furthermore, the basement membrane of the dilated blood vessels was positive for periodic acid-Schiff stain and collagen type IV immunohistochemical staining. Based on these clinicopathologic features, we diagnosed CCV. Herein, we report an interesting case of CCV, which is the first report in Korea.

Superficial CD34-positive fibroblastic tumor (SCPFT) is a recently described disease entity characterized by marked nuclear pleomorphism, low mitotic count, and diffuse CD34 positivity. It is a rare, distinctive, low-grade fibroblastic neoplasm. To date, only 44 cases have been reported in the English-language literature. Herein, we report two cases of SCPFT involving a 48-year-old male and a 22-year-old male with superficial tumors on the right and left thighs, respectively. Excision was performed in both cases. Histologically, both tumors showed spindle-to-epithelioid cells arranged in fascicular or sheet-like patterns. Most cells displayed granular or eosinophilic glassy cytoplasm, marked nuclear pleomorphism, and a low mitotic rate. On immunohistochemical staining, tumor cells were diffusely positive for CD34 and negative for S100 protein, smooth muscle actin, and desmin. After wide excision, neither patient experienced recurrence or metastasis after 16 months and 11 months of clinical follow-up, respectively. To the best of our knowledge, these are the first two cases of SCPFT reported in Korea. We believe these case reports would contribute to the clinicopathological understanding of SCPFT and assist clinicians in differentiating this tumor from other superficial soft tissue neoplasms.

Spindle cell lipoma is a rare benign neoplasm that features a mixture of evenly aligned spindle cells, mature adipocytes, and ropey collagen. Most cases of spindle cell lipoma are found in the subcutaneous tissue, and intradermal spindle cell lipoma is rarely reported. We present a case of intradermal spindle cell lipoma in a 46-year-old female who presented with a 0.7-cm flesh-colored and dome-shaped nodule on the right temple that had developed 6 years ago. This mass was excised, and upon histopathologic examination, an unencapsulated lesion was located in the dermis, which consisted of bland spindle cells, scanty mature adipocytes, rare lipoblasts, and ropey collagen bundles with prominent basophilic myxoid stroma. Immunohistochemical staining showed diffuse positivity for CD34, negativity for the S-100 protein, and loss of retinoblastoma protein expression. Based on these features, intradermal low-fat spindle cell lipoma was diagnosed. No evidence of local recurrence was observed 4 months after excision. Intradermal low-fat spindle cell lipomas are extremely rare and can easily be mistaken for tumors that have similar clinical and histopathological findings. Herein, we report a globally rare case of an intradermal low-fat spindle cell lipoma.

Background: Inverted follicular keratosis (IFK) is a benign tumor that occurs mainly as a single lesion in the head and neck. Histologically, the tumor lobules show endophytic or exophytic growth and are characterized by squamous eddies. IFK should be differentiated from seborrheic keratosis, verruca vulgaris, and squamous cell carcinoma (SCC).In particular, differentiating from well-differentiated SCC can be difficult when downward growth is observed along with some mitotic figures and inflammatory cell infiltration. Objective: To evaluate and compare the clinical and histopathological characteristics of IFK and well-differentiated SCC. Methods: We retrospectively reviewed the clinicopathological records of 21 patients diagnosed with IFK and 21 randomly assigned patients diagnosed with well-differentiated SCC between 2000 and 2022 at the Dermatology Department of the Yeungnam University Medical Center. Results: IFK occurs frequently on the head and neck of middle aged and older adults, and its average size is less than 1 cm. Acantholysis was observed in varying degrees in IFK; however, well-differentiated SCC was mostly absent (17 cases) or mild (three cases) showing a statistically significant difference. Squamous eddies were observed in 21 cases of IFK and eight of well-differentiated SCC. The average number of dyskeratotic cells and mitotic counts did not differ significantly between IFK and well-differentiated SCC. Conclusion We suggested some evidence for the irritant origin of IFK. We also compared the clinicohistological findings of IFK with those of well-differentiated SCC and concluded that excluding atypical cells, abnormal mitotic figures, and irregular invasive borders is important for differential diagnosis.

Methotrexate (MTX)-induced accelerated nodulosis (MIAN) reportedly occurs in patients with rheumatic arthritis receiving MTX therapy. However, it has also been reported in patients with other autoinflammatory conditions, such as systemic lupus erythematosus (SLE).A 38-year-old woman diagnosed with SLE presented with multiple movable, firm, fleshcolored nodules on both hands that had developed 3 years ago. She was taking oral medications, specifically hydroxychloroquine, azathioprine, and MTX. Histopathological examination revealed palisaded granulomatous inflammation, surrounded by histiocytes and lymphocytes, along the dermis to the subcutaneous fat layer. Fibrinoid degeneration was observed at the center of the granulomatous inflammation, and dermal mucin deposition was not observed. The patient was diagnosed with MIAN, and therefore discontinuation of MTX was recommended. Subsequently, the lesions almost completely disappeared with no signs of recurrence. MIAN exhibits clinicopathological features similar to those of rheumatoid nodules; therefore, it can be easily misdiagnosed. Herein, we report a case of MIAN in a patient with SLE to contribute to the accurate diagnosis and appropriate management.

Piloleiomyoma originates from the arrector pili muscles. Multiple piloleiomyoma lesions may occur, especially on the trunk and extremities. However, multiple lesions throughout the body are rare. We present a case of generalized cutaneous piloleiomyomatosis in a 72-year-old man who had numerous lesions throughout his body. Clinically, the patient presented with fixed and non-tender reddish to brownish papules and nodules mainly on the back and extensors of extremities. Punch biopsy was performed, and the specimen was stained with hematoxylin and eosin, revealing interweaving fascicles of cigar-like spindle cells on the upper dermis. On immunohistochemical staining, tumor cells were positive for smooth muscle actin. Based on these features, we diagnosed the patient with generalized cutaneous piloleiomyomatosis.