ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 dyskeratotic cells and prominent acantholysis. It is usually found on the sun exposed areas such as the face and the neck in the elderly with a male predominance. It presents as a nodule with various colors, accompanied by scaling, crusting, and ulceration like the other variants. Histological examination is necessary for making the accurate diagnosis. ASCC is a more-aggressive tumour with higher potential for recurrence or metastasis. E-PS-05-037 A rare and sometimes fatal syndrome: Stevens-Johnson D. Sá*, A. Coelho, F.S. Vieira, J.R. Vizcaíno *Centro Hospitalar Universitário do Porto, Portugal Background & objectives: In 1922, Stevens and Johnson described a strikingly distinct disease in 2 children as an “extraordinary, generalized eruption with continued fever, inflamed buccal mucosa and severe purulent conjunctivitis.” Methods: We herein present the case of a 49-year-old man with a history of stage IV follicular lymphoma that was being treated with antibiotics for an infected skin ulcer. On the 14th day of his hospital stay he developed a generalized pruritic and painful skin rash with oral mucosal involvement. The rash progressed with the formation of vesicles and skin erosions. Results: The patient was submitted to a skin biopsy to try to dis- tinguish between the clinical differential diagnosis of erythema multiforme and Stevens-Johnson syndrome. We received a skin punch biopsy measuring 6 mm diameter and 4 mm thick with no apparent lesions on the epidermal surface. Histologic examina- tion showed numerous apoptotic bodies at different levels of the epidermis, in some areas with confluent necrosis of the epider- mis and focal lymphocyte exocytosis. Apoptotic bodies were also identified on the follicular epithelium. The dermis showed only a mild superficial perivascular lymphohistiocytic inflammation. All these changes were compatible with the clinical diagnosis of Stevens-Johnson syndrome and the presumable drug responsible was piperacillin-tazobactam. Conclusion: Stevens-Johnson syndrome is a rare, severe, immune-mediated cutaneous reaction usually secondary to an idi- osyncratic reaction to medication, although infection with Myco- plasma pneumoniae is also a well-documented cause. The histo- logic features are variable epidermal apoptosis associated with basal cell hydropic degeneration or subepidermal vesiculation. Lymphocytic exocytosis may be present and a mild perivascular infiltrate of lymphocytes, macrophages, and melanophages is present in the superficial dermis. The mortality is approximately 5% and, sadly, our patient died 4 days after the skin biopsy. E-PS-05-038 Pleomorphic basal cell carcinoma of the eyelid: an uncom- mon case report S. Mabrouk*, N. Abdessayed, Z. Nfikha, Y. Fejji, Z. Lajmi, L. Knani, M. Mokni *Department of pathology, Farhat Hached university hospital, Tunisia Background & objectives: Pleomorphic basal cell carcinoma (BCC) is a rare variant of BCC characterized by the presence of scattered large, pleomorphic cells. It is commonly located on the head and neck. The prevalence is unknown, fewer than 60 cases are reported in the literature. Methods: A 82-year-old female without any particular medical history, presented with a left lower external eyelid nodule. Ophthalmic examination revealed a firm pigmented lesion at the eyelid, measuring 1 cm with surface irregularity and ulceration, and bleeding on contact. BCC was suspected, and a full-thickness eyelid resection was performed. The specimen was oriented and referred to pathological diagnosis. Results: On gross examination, the specimen is centered by pigmented lesion with ulcerating surface measuring 1cm x 0,9cm. Surgical margins were distant from the lesion. On histological examination, the lesion was composed of nests of basaloid cells with peripheral palisading and stromal retraction. Tumour cells were predominantly small with scant cytoplasm and monotonous nuclei. Scattered giant cells with large, irregular, hyperchromatic nuclei and prominent nucleoli were observed. Mitoses were numerous with frequent atypical ones. The overall histologic features were highly suggestive of pleomorphic BCC. Surgical margins were free. Conclusion: BCC has several histologic subtypes that often have variable outcomes and prognoses. Pleomorphic BCC is an uncom- mon pathologic variant of unknown pathogenesis. Eyelid localiza- tion is extremely rare, with only one case reported in the literature. The cardinal histological sign is the presence of scattered enlarged mononuclear and/or multinucleated tumour cells. However, the presence of atypical giant cells doesn’t worsen the prognosis which is similar to the classical variant. Histological differential diagnosis of BCC is sometimes challenging, especially with adnexal tumours. E-PS-06 | E-Posters Digestive Diseases Pathology - GI E-PS-06-001 Superficial “early” colon cancer showing extraordinary dis- tant metastases, simulating a gynaecologic origin – potential diagnostic pitfall T. Kawasaki*, R. Terada, S. Sato, A. Yabuno, H. Inui, R. Jinushi, Y. Nakano, T. Ogawa, S. Ryozawa, Y. Watanabe, A. Kataoka, T. Fujii, K. Deguchi, Y. Hirano, Y. Usami, H. Imada, R. Kawamura, T. Tashima *Department of Pathology, Saitama Medical University Interna- tional Medical Center, Japan Background & objectives: Herein, we describe an exceptionally rare case with superficial bowel cancer showing extensive peritoneal, including omental, dissemination accompanied by ovarian metastases. The patient, a 70-year-old postmenopausal Japanese woman, presented with abdominal distension. Methods: Computed tomography revealed huge bilateral ovarian tumours with multiple peritoneal metastases, suggesting advanced ovarian cancers (cT3cNXM0). The salpingo-oophorectomy specimens contained grey-whitish to reddish brown, solid tumours with cystic formation, measuring 15x9x7 cm in the right ovary and 18x10.5x9 cm in the left ovary, respectively. Furthermore, numerous omental nodules, up to 1.2 cm in maximum diameter, had similar cut surface appearances. Results: These invasive tumours were histopathologically com- posed of tubular, cribriform and/or papillary growths of columnar carcinoma cells with enlarged, hyperchromatic nuclei with distinct nucleoli. Coagulation necroses were pronounced. Immunohisto- chemically, the carcinoma cells were diffusely positive for cytoker- atin (CK) 20, CDX2 and SATB2, and negative for CK7, PAX8 and ER. These pathological features suggested metastatic colon adeno- carcinoma. We thus performed lower gastrointestinal endoscopy and detected a superficial, elevated lesion with a depressed area, measuring 15 mm, in the sigmoid colon, suggesting submucosal invasion. This lesion was pathologically confirmed to be tubu- lar adenocarcinoma. Also, macroscopic peritoneal disseminated S216