ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 elastic cut surface. The lesion was excised and sent for histologi- cal examination. Results: Histopathology confirmed two different lesions in association. An overlying baso-squamous BCC in the overlying epidermis and reticular dermis and an underlying symmetric relatively circumscribed with indefinite borders dermal based lesion consisting of a mixture of fibroblasts and histiocytes arranged in fascicles with storiform pattern. The BCC component was positive for CK5/6, p63, p40, BerEP4 and bcl-2 and the concomitant lesion for CD68/KP1 and negative for S-100 and EMA. The final diagnosis was of a collision tumour consisting of a metatypical BCC overlying a dermatofibroma. Conclusion: Dermatofibromas and BCCs are common lesions. Their coexistence within one lesion is uncommon. DFs can be associated with a variety of benign lesions of the overlying epidermis including pseudoepitheliomatous hyperplasia, to basaloid proliferations to BCC, Bowen disease and melanoma. Basal cell proliferations and BCCs are said to be the result of the inductive effect of DF on the epithelial cells of the hair follicle. The association with metatypical BCC has not previously been described and can contribute to the histogenesis. E-PS-05-008 Eccrine porocarcinoma metastasized in the lung - a case report N. Novkovic*, M. Papazian, G. Stanc, M. Sevastiadou, C. Vala- vanis, E. Souka *Pathology Department Metaxa Cancer Hospital, Greece Background & objectives: Eccrine porocarcinoma (EPC) is a rare malignant cutaneous adnexal tumour, representing 0.005% to 0.01% of all cutaneous tumours. Can arise de novo or from pre-existing poroma. Chronic light exposure and immunosuppression proposed as factors that contribute to the malignant transformation. Methods: We received, from a 56-year-old female, a skin biopsy composed by small fragments of skin from inguinal region. Results: On histological examination the dermis was infiltrated by epithelioid malignant cells with eosinophilic cytoplasm, moder- ate to severe nuclear atypia, prominent nucleoli and brisk mitotic activity ≥ 3-5 mitosis/1HPF. The cells are arranged in nests with fibrous septa between them. Necrosis was present. The neoplasm extends widely to the surgical margins. Immunochemistry was positive for CK7, EMA, CK5/6, p63, EGFR, E-cadherin, CD10 and GATA-3. Ki-67 was positive 90% of neoplastic cells. Negative immunoractivity for Melan A, HMB45, ER, PgR, AR and p16 was observed. The diagnostic of eccrine porocarcinoma was made. We recommended wider skin excision and control of the regional lymph nodes, lung and bone. Further investigation revealed lung metastasis. Conclusion: The lower extremities and head and neck are the most common primary sites for EPC. Because malignant transforma- tion of previous benign lesion could be happened, any spontane- ous bleeding, ulceration, itching, pain and sudden growth must be investigated. Due to its rarity and no specific clinical manifesta- tions, it is generally difficult to suspect EPC as initial clinical diagnosis. E-PS-05-009 The relative composition and distribution of the mononuclear inflammatory cell infiltrate in common melanocytic nevi G. Tudor*, O. Stefan, S. Zurac, L. Cristina, D. Boda, C. Caruntu *Colentina Clinical Hospital, Romania Background & objectives: Melanocytic nevi are frequently associated with inflammatory cells of different types and varied proportions. Our study aims to evaluate the mononuclear inflammatory cell in com- mon melanocytic nevi (CMN) with intravascular nevus cell protrusion (IVNP) and intravascular nevus cell aggregates (IVNcA). Methods: We performed a case control study comparing 30 CMN with IVNP and IVNcA and 30 matched CMN without IVNP and IVNcA and stained them for CD3, CD 4, CD 8, FOXP3, CD 20 and CD 11c, assessing the distribution and composition of the positive cells in the inflammatory cell population with their median and p-values using the student t test. Results: The inflammatory infiltrate in all CMN was minimal, predominantly distributed perivascular, periadnexal and in the stroma surrounding the nevi, mainly consisted of T-cells in both groups, significantly higher (p=0.047) in the nevi with IVNP and IVNcAs. CD4+:CD8+ ratio varied from 1:3 to 4:1, without noteworthy differences between the two groups and the FoxP3+ cells were very sparse regardless of the type of nevus. The monocytic/macrophagic population CD11c+ was the second largest component of the inflammatory infiltrate and remarkably higher (p=0.02) in the nevi with IVNP and IVNcAs, compared to common melanocytic nevi without these features. Conclusion: The microenvironment of benign melanocytic lesions consists of low counts of immune cells, scattered around the stroma and nevus cells, most of which are CD3+ cells, followed by macrophages and with very few CD 20+ lymphocytes; this layout is mainly observed in nevi with IVNP and IVNcAs. A better understanding of the mononuclear cells role played in the pathogenesis of the vascular affinity of melanocytes is needed through further research. Funding: This work was supported by a grant of Romanian-Min- istry-of-Research-and-Innovation, CCCDI-UEFISCDI, project number 61PCCDI/2018PN-III-P1-1.2-PCCDI-2017-0341. E-PS-05-010 Clinical pitfall, an incidental umbilical melanoma, a case report S. Kartal*, E. Tuncer, H. Özer *Sivas Cumhuriyet University, Turkey Background & objectives: Melanoma is the third prevalent skin cancer, commonly seen in sun-exposed skin. 43% of all umbilical tumours are malignant and classified as primary or metastatic. Primary malignancies represent 12-20% of all umbilical malignancies. Umbilical melanoma is extremely rare. Methods: The case of umbilical melanoma operated with the previously diagnosed as granuloma was evaluated in terms of clinical and pathological features. Results: A 48-year-old female patient presented to general surgery clinic with main complaint of abdominal pain also suffered from mild discoloration and swelling in the umbilicus. After examination the patient was diagnosed as chronic cholesystitis and umbilical granuloma and operated. The gallbladder and umbilical material of the patient sent to our laboratory. When the specimen pre-diagnosed as umbilical granuloma was examined, we saw an ulcerated, well-circumscribed nodular pigmented lesion on umbilicus with a diameter of 3 cm. As a result of microscopic examination, the case was reported as Clark level 4, pT4b melanoma. Unexpected Malignancy was reported as a panic diagnosis. Conclusion: As in our case, the diagnosis of umbilical melanoma is often made in the late stages, possibly because the umbilicus is an area that is often not discovered during skin cancer screening and the patient delays seeking medical attention. Even in it is found to be incidental, S208