Pagetoid reticulosis in a 13-year old female. A unique immunohistochemical profile

Report on a Rare Case of Limited CD4/CD8 Double-Positive Paget Reticulosis with Literature Review

Restricted pagetoid reticulosis, also known as Woringer-Kolopp disease, represents a rare cutaneous lymphoproliferative disorder categorized as an isolated variant of mycosis fungoides. This report presents a case involving limited pagetoid reticulosis affecting the right upper extremity in a 25-year-old female. The patient had been experiencing plaques on the right upper extremity for a decade. Dermatologic examination revealed well-defined scaly plaques on the right forearm, surrounded by hyperpigmented patches. Skin histopathology demonstrated atypical mononuclear cell infiltration in the lower part of the epidermis, forming nests. Immunohistochemistry indicated CD3+, CD4+, CD5+, CD7+, CD8+, CD30+, and Ki-67-positive staining. Additionally, CD20, CD79α, and PD-1 were negative. Monoclonal rearrangement of T-cells was identified in TCR β and TCR γ through clonality assessment. The diagnosis of limited paget-like reticulocyte hyperplasia was established, leading to surgical resection. A review of the literature affirmed the variable immunophenotype of pagetoid reticulosis, with atypical cells exhibiting four types: (1) CD3+, CD4+, CD8+-type; (2) CD3+, CD4-, CD8+-type; (3) CD3+, CD4-, CD8-type; and (4) CD3+, CD4+, CD8+-type-relatively uncommon in the restrictive type. This case report details the clinical features, histologic and morphologic characteristics, immunohistochemical phenotype, diagnosis, and differential diagnosis of a rare CD3+, CD4+, CD8+ limited pagetoid reticulosis. The lesion was surgically resected, and the patient underwent a 3-year follow-up to observe its prognosis.

Pagetoid reticulosis

Pagetoid reticulosis (PR) is a rare type of mycosis fungoides. Clinical symptoms of PR can mimic other skin diseases of papulosquamous, neoplastic, and infectious origin that hampers PR diagnostics. The main histopathologic feature of PR is dense intraepidermal infiltration by medium to large-size lymphocytes through the epidermis leading to pagetoid plaque formation. There are three common immunophenotypes of PR: CD4-positive T-helper phenotype (CD3+, CD4+, CD8); T-cytotoxic/suppressor (CD3+, CD4, CD8+); and double negative phenotype (CD3+, CD4, CD8). The clinical case of PR with rare immunophenotype (CD2+, CD3+, CD8+ lymphoid infiltrate) is presented. The careful analysis of the symptoms, pathomorphological and immunohistochemical data is necessary for accurate PR diagnostics.

Primary cutaneous T-cell lymphomas in childhood and adolescence

Primary cutaneous lymphomas are extranodal non-Hodgkin lymphomas of T- or B- cell origin, that predominantly affect older patients but have been reported in all age groups and as early as in the first years of life. Diagnosis of cutaneous lymphomas is challenging and requires high clinical suspicion and close collaboration between dermatologists, pediatric oncologists and pathologists. Skin involvement of non-Hodgkin lymphomas in children or adolescents can either be primary cutaneous or secondary due to an underlying nodal lymphoma. The most common primary cutaneous lymphomas encountered in children are of T-cell origin, with mycosis fungoides being the most prevalent cutaneous T-cell lymphoma, followed by CD30⁺ lymphoproliferative disorders. While cutaneous lymphomas share clinicopathologic characteristics between juvenile and adult forms, there are important differences in terms of clinical presentation, diagnosis and treatment. The hypopigmented variant of mycosis fungoides seems to be overrepresented in the pediatric age group. Prognosis and treatment of mycosis fungoides are stage dependent. The majority of children present with early-stage disease and respond well to topical corticosteroids and phototherapy.

Primär kutane T‐Zell‐Lymphome im Kindes‐ und Jugendalter

Primär kutane Lymphome sind extranodale T- oder B-Zell-Non-Hodgkin-Lymphome, die vorwiegend ältere Patienten betreffen, aber in allen Altersgruppen einschließlich der ersten Lebensjahre auftreten können. Die Diagnose kutaner Lymphome ist eine Herausforderung und erfordert einen hohen klinischen Verdacht sowie enge Zusammenarbeit zwischen Dermatologen, pädiatrischen Onkologen und Pathologen. Generell müssen primär kutane Lymphome von sekundär kutanen Lymphomen, welche meist von nodalen oder extranodalen Lymphomen ausgehen, unterschieden werden. Die häufigsten primär kutanen Lymphome im Kindesalter sind T-Zell Lymphome, wobei Mycosis fungoides das häufigste kutane T-Zell-Lymphom darstellt, gefolgt von CD30+ lymphoproliferativen Erkrankungen. Während klinisch-pathologische Merkmale kutaner Lymphome bei Jugendlichen und Erwachsenen ähnlich sind, gibt es wichtige Unterschiede bezüglich klinischer Präsentation, Diagnose und Behandlung. Die hypopigmentierte Variante der Mycosis fungoides scheint in der pädiatrischen Altersgruppe überrepräsentiert zu sein. Prognose und Behandlung der Mycosis fungoides sind stadienabhängig. Die Mehrheit der Kinder weist ein frühes Krankheitsstadium auf und spricht gut auf topische Kortikosteroide und Phototherapie an.