ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 Amyloid deposits within the skin biopsies in AL type were in the papillary dermis, interstitial infiltration, and hair follicle shaft involvement. In AA-type skin biopsies showed amyloid infiltration at the sweat glands and hair follicle shaft involvement. In non-AL/ Non-AA type the amyloid deposits described an interstitial infiltra- tion and deep small blood vessel wall deposition. In a subgroup of biopsies(N=13), C4d staining was evaluated for identifying amy- loid deposition being positive in 84,6%(n=11) of cases. Conclusion: The diagnosis of SA sampling abdominal fat tissue has variable rates of sensitivity. Skin biopsy is a simple proce- dure providing valuable findings for amyloidosis. Descriptions of skin involvement and histopathological findings in SA are scant noticing skin compromise in 40% of cases. We detected amyloid deposits at different layers and components of the skin, increasing the probability of detection of SA, supporting this procedure as a diagnostic tool, especially for AL-type amyloidosis where positive findings are frequently detected allowing an early diagnosis for this condition. OFP-07-005 Rare histopathological findings in erythema migrans: a 5 year retrospective study from Freiburg Dermatopathology Unit and review of the literature C. Faria*, A. Pina, K. Deml, K. Wallerius, S. Kraft, S. Hörster, W. Weyers *Pathology Unit, Hospitais da Universidade de Coimbra, Centro Hospitalar e Universitário de Coimbra, Portugal Background & objectives: Erythema migrans represents the skin lesion of early manifestation of Lyme disease typically as an erythematous, circular, annular plaque with central clearing, generally greater than 5cm. Some cases can be defiant, leading to a histopathological evaluation, occasionally with uncommon findings. Methods: We describe 88 cases with PCR test positivity for Bor- relia burgdorferi and diagnosis of erythema migrans with rare his- topathological findings diagnosed from 2016 to 2021. Our series had a female predilection, representing 71% of total patients and an age distribution between 21 and 82 years old. There was correlation with the clinical information in 59% of the cases. Results: Erythema migrans is characteristically described as a superficial and deep perivascular inflammatory infiltrate, predominantly composed by lymphocytes with occasional plasma cells and eosinophils. Besides these features, our study presents cases with rare findings. There were inter- face changes like vacuolar and lichenoid infiltrate in 29% of the cases. Granulomatous features were present in 50,6% of this casuistic, with granuloma formation and a predominantly interstitial histiocytic infiltrate. There was also observed a pseudolymphomatous pattern with superficial, deep and severe lymphocytic infiltrate in 17% of the cases. And 3,4% of these patients presented with histopathological findings similar to mycosis fungoides with epidermotropism and papil- lary dermal fibroplasia. Conclusion: The diagnosis of erythema migrans is usually clin- ical and serologic testing is not recommended due to low sen- sitivity; but some difficult clinical cases benefit from a biopsy evaluation. However, the findings can be too subtle and unu- sual, suggesting other entities like granuloma annulare, lupus erythematosus, drug eruptions, and mycosis fungoides, all of which require a distinct therapeutic approach. Although those differential diagnosis can often be excluded with additional histopathologic findings, close clinicopathologic correlation is necessary for a definite diagnosis. OFP-07-006 Cutaneous lupus erythematosus: a 5-year casuistic study from a Portuguese dermatopathology department C. Faria*, A. Alves, C. Courelas, O. Tellechea, J.C. Cardoso *Pathology Unit, Hospitais da Universidade de Coimbra, Centro Hospitalar e Universitário de Coimbra, Portugal Background & objectives: Cutaneous lupus erythematosus (LE) occurs in the context of systemic LE or restricted to the skin, and it can be subclassified into acute, subacute or chronic. While there are differences between them, some histopathological hallmarks are present in most subtypes. Methods: Retrospective study of 54 patients with histopathological diagnosis of cutaneous lupus erythematosus from 2016 to 2021. There was a female predilection representing 70,4% and our study had a broad age distribution, the youngest case with 8 years-old and the oldest one with 88 years-old, with almost 6% of cases being diagnosed at the paediatric age. Results: Cutaneous lupus erythematosus diagnosed in the setting of systemic lupus erythematosus represents 13% of the patients while the cases limited to the skin represent 87%. Subacute cutane- ous lupus erythematosus accounts for 23,4% and chronic cutaneous LE 76,6%. No cases of acute lupus erythematosus were described. In our study, discoid LE (DLE) is the most common subtype of chronic cutaneous LE (69,4%), followed by tumid LE (19,4%). Bullous LE represents 5,6%, while hypertrophic / verrucous LE and lupus panniculitis account for 2,8% each. Four cases (8,4%) were diagnosed in the context of scarring lymphocytic alopecia. Conclusion: The diagnosis of cutaneous LE requires clinical and histopathological correlation. However, the overlap with other connective tissue diseases warrants integration of serologic findings, as a systemic autoimmune disorder may be considered in the differential diagnosis. Our study also reveals that the majority of cases were responsive to treatment, presenting only hyperpigmented residual lesions. Nevertheless, 11% had persistent lesions, especially patients with other associated autoimmune diseases like Sjogren syndrome, psoriasis and alopecia, or in the context of HIV infection. OFP-07-007 Correlation between line-field confocal optical coherence tomography and histopathology. Preliminary results R. Caltabiano*, G. Broggi, F. Lacarrubba, A.E. Verzì, G. Micali *Department of Medical and Surgical Sciences and Advanced Technologies "G.F. Ingrassia", Anatomic Pathology, University of Catania, Italy Background & objectives: Line-field confocal optical coher- ence tomography (LC-OCT) is a new, non-invasive technique that provides in-vivo, high-resolution images in both vertical and horizontal sections. Our study evaluated LC-OCT imaging in some inflammatory disorders and to correlate the resulting features with histopathology. Methods: The retrospective study included patients with his- topathological confirmed diagnosis of plaque psoriasis, atopic eczema and lichen planus, who were imaged with LC-OCT before the biopsy. LC-OCT was performed with the commercially avail- able LC-OCT device. Results: A total of 15 adult patients with histopathologically proven plaque psoriasis (N: 5), atopic eczema (N: 5), and lichen planus (N: 5) were included. In all cases, LC-OCT allowed the in-vivo recognition of the main microscopic features of the exam- ined inflammatory skin disease, with a strong correlation with histopathology. S29