Case Presentation A female with Fitzpatrick skin type IV, in her late 50s, presented with erythematous, mildly itchy nodules over the lateral aspect of the face for 2 years Figure 1A and B. The lesions were progressive in size and number. The largest lesion, measuring 4 cm, was smooth surface, and was freely mobile. The patient was healthy systemically, with no other comorbidities. There was no history of weight loss, night sweats, or chronic fever. Dermoscopy (Dermlite DL4, 3 Gen, CA, USA; ×10 magnification, polarized mode) revealed a pink to red background with overlying linear, branched polymorphous vessels Figure 2A and B. The haematological and biochemical investigations were normal. A skin biopsy from the erythematous nodule showed a flattened epidermis with thinned-out rete ridges Figure 3A. The mid to deep dermis and subcutaneous tissue showed a nodular infiltration of lymphocytes without any atypical lymphoid cells Figure 3B. On immunohistochemistry (IHC), lymphoid aggregates showed CD20+ B-lymphocytes with germinal center formation surrounded by CD3+ T cells Figure 4A and B. CD5 and BCL2 were positive in the background reactive T-cell population Figure 5A and B. CD10 was positive in germinal center B lymphocytes, whereas CD23 highlighted the maintained follicular dendritic cell meshwork Figure 5C and D. The Ki-67 index showed a reactive pattern of nuclear positivity. Based on these findings a final diagnosis of cutaneous B-cell pseudolymphoma was made. Upon detailed inquiry to find out the cause of pseudolymphoma, we evaluated the history of triggers and confirmed that the patient had experienced repeated insect bites whenever she visited the farm. The patient was treated with intralesional triamcinolone acetonide 2.5 mg/mL every 4 weeks, and daily tacrolimus 0.1% cream application was advised twice a day as maintenance therapy. The patient was counseled about treating the triggering factors responsible for her condition to prevent recurrences. There has been mild improvement in the cutaneous nodules, and the patient remains under regular follow-up. Figure 6A and B.Figure 1: (A, B) Erythematous nodules over the lateral aspect of the faceFigure 2: (A, B) Polarized dermoscopy showing red to orange background with overlying polymorphous vesselsFigure 3: (A) Histopathology showing grenz zone, nodular infiltration of upper to mid dermis, and Subcutaneous tissue (H however, dermoscopy is increasingly recognized as a useful noninvasive tool, aiding only in the preliminary assessment of suspicious lesions as the findings are nonspecific. Despite growing evidence regarding dermoscopic findings in conditions like mycosis fungoides, data remains limited for nodular or plaque-like lymphoid proliferations.2-4 CPL represents a benign, reactive, polyclonal process that may be localized or disseminated, transient or persistent, and can arise following triggers such as insect bites, tattoos, medications, infections (e.g., Borrelia burgdorferi), or trauma, although many cases remain idiopathic. In India, specific prevalence data for B-CPL are limited. In a clinicopathological study of 30 cases of CPL, 11 cases (36.7%) were identified as B-cell type.5 The study concluded that none of the cases were suspicious for cutaneous lymphoma upon applying IHC, underscoring the importance of accurate diagnosis to avoid unnecessary aggressive treatments. Lymphocytoma cutis (LC), a type of cutaneous B-CPL associated with Borrelia infection, is rarely seen in India. A case report described an 11-year-old boy of German descent residing in India who presented with LC.6 The rarity of such cases in India may be attributed to the low incidence of Lyme disease in the region. The various differential diagnoses of a patient suspected of pseudolymphoma are listed in Table 1. A skin biopsy is a critical step in the diagnosis of B-CPL; there are features such as dense lymphoid infiltrates in the dermis with the formation of lymphoid follicles with germinal centers, which can significantly overlap with low-grade lymphomas, especially primary cutaneous follicle center lymphoma or marginal zone lymphoma.7 Therefore, histopathology alone may not be definitive. IHC staining is essential for the confirmatory diagnosis of CPL. It helps in determining the polyclonal or monoclonal nature of the infiltrate. While IHC does not directly measure disease severity (e.g., lesion size, number, or symptoms), it helps assess the underlying biology of the infiltrate. A polyclonal infiltrate (evidenced by balanced kappa/lambda expression and mixed B- and T-cell populations) is usually associated with benign, self-limiting, or indolent disease, whereas a monoclonal infiltrate or dominant B-cell population with architectural disruption and high BCL2 expression may indicate more persistent, extensive disease or risk of underlying neoplasia.5 Although true progression of B-CPL to lymphoma is rare, persistent antigenic stimulation—whether infectious, iatrogenic, environmental, or idiopathic—may sustain lymphoid proliferation, warranting close clinical surveillance. Clinical features such as rapid progression, systemic symptoms, or resistance to conservative therapy should prompt further work-up to exclude cutaneous B-cell lymphoma. Currently, there are no standardized treatment guidelines for CPL, making clinical trials and individual case studies important. Newer treatment approaches include targeted therapies like Rituximab (anti-CD 20, corticosteroid-refractory CPL), Dupilumab monoclonal antibody targeting interleukin-4 receptor alpha (IL-4Rα), which blocks IL-4 and IL-13, and potential use of mycophenolate mofetil.8,9 These agents target specific cellular pathways and have shown promise in refractory cases, though clinical guidelines are still evolving.Table 1: Differential diagnosis of cutaneous pseudolymphomaIn conclusion, a systematic diagnostic approach combining dermoscopy, histopathology, and IHC is essential to distinguish it from malignant counterparts and prevent unnecessary aggressive treatment. Dermoscopic findings are nonspecific and may not aid in the differentiation of malignant neoplasms. Identifying potential triggers and initiating appropriate therapy can lead to favorable outcomes. Regular follow-up is important to monitor for persistence, recurrence, or rare progression. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.
Singh et al. (Wed,) studied this question.