case_images: PMC9772430_01
case_images: (A) A reddish plaque on the skin of the right lower abdomen with a diameter of 2.5 cm. (B) The HE x40: The tumor presented as an exo-endophytic proliferation with a dermal multinodular, well-circumscribed growth connected to the epidermis (blue line), and an invasive focus of frankly atypical epithelium could be observed (white arrow). (C) The HE x400: The tumor was composed of clear, monomorphic cells with mitosis. (D) The HE x100: Tumor thrombus could be observed (white arrow).
case_images: fonc-12-1019140-g001.jpg
case_images: PMC9772430_01_fonc-12-1019140-g001.jpg
case_images: f1
case_images: A 63-year-old female found a peanut-sized red plaque occasionally on her right lower abdomen skin in February 2019, and after 5 months, the plaque suddenly increased to 2.5 cm with purulent discharge exudation and bled after rubbing, but with no pain ( Figure 1A ). The postoperative pathological diagnosis was trichilemmal carcinoma with margin-free but with tumor thrombus (  Figures 1B-D  ).
case_images: (A) A mass in the right axilla. (B) Preoperative enhanced CT revealed a soft tissue density mass (yellow arrow) in the right axilla with a size of 6.9 x 5.2 cm. (C, D) PET-CT showed the mass as axillary lymph node metastasis (blue arrows) and another metastasis located at the ipsilateral inguinal lymph node (yellow arrows) which were characterized by shapes of nuclide accumulations in PET-CT image. (E) An intraoperative view from above, showing the tumoral invasion of the pectoralis major and minor muscles (white arrow). (F) An intraoperative view from above, showing the axillary vein (white arrow) after ALND. (G) The tumor was 7 cm in diameter. (H) The HE x100 showed the tumor was characterized by a proliferation of tumoral lobules composed of large, atypical cells with clear cytoplasm.
case_images: fonc-12-1019140-g002.jpg
case_images: PMC9772430_01_fonc-12-1019140-g002.jpg
case_images: f2
case_images: The right axillary mass was progressively increasing to 6.9 x 5.2 cm after two courses (21 days per course) of chemotherapy (docetaxel + DDP) ( Figures 2A-D ). The tumor was 7 cm in diameter, invading the pectoralis major and minor muscles and the axillary vein's sidewall ( Figures 2E-G ), with multiple enlarged lymph nodes in the axilla. The postoperative pathology confirmed the tumor and axillary lymph nodes as metastases (12/28 positive) ( Figure 2H ).
case_images: (A) An enhanced CT of the chest showed no recurrent manifestation in the right axilla compared with preoperative PET-CT. (B) CT follow-up revealed the disappearance of the lesion in the right inguinal region after adjuvant radiotherapy compared with preoperative PET-CT.
case_images: fonc-12-1019140-g003.jpg
case_images: PMC9772430_01_fonc-12-1019140-g003.jpg
case_images: f3
case_images: The patient tolerated the treatment well, and no severe adverse events occurred except for inflamed skin in the right axilla, which recovered soon at the end of radiation. After radiotherapy, regular ultrasound and CT follow-up revealed the disappearance of the lesion in the right inguinal region (  Figure 3B  ). The patient has shown no signs of recurrence or metastasis for one year since last radiotherapy.