Dermoscopy and the diagnosis of primary cutaneous B-cell lymphoma

Non-Invasive Imaging Including Line-Field Confocal Optical Coherence Tomography (LC-OCT) for Diagnosis of Cutaneous Lymphomas

Background/Objectives: Primary cutaneous lymphomas (PCL) are a heterogeneous group of non-Hodgkin lymphomas arising from malignant T (CTCL) or B (CBCL) cells, often mimicking other skin conditions. Recently, non-invasive diagnostic imaging modalities, including dermoscopy, Reflectance Confocal Microscopy (RCM), and Line-field Optical Coherence Tomography (LC-OCT), have become increasingly important, supporting clinicians in clinical practice. Hence, our study aimed to describe dermoscopic, RCM, and LC-OCT features of PCL and to explore their role in PCL management. Methods: Between December 2022 and January 2024, 40 lesions of 25 patients with PCL were retrospectively analyzed at the Dermatologic Unit of the University of Siena, Italy. Predefined dermoscopic, LC-OCT, and RCM criteria were assessed and their frequencies were calculated. Results: At dermoscopy, CTCL lesions were characterized by pinkish structureless areas (58,6%) and homogeneous distributed dotted vessels (35,7%), whereas 57.1% of CBCL presented with orange-yellow structureless areas. Considering CTCL, lymphocytes in the epidermis, dermal-epidermal junction, and dermis were detected by LC-OCT in 73.1%, 66.7%, and 51.9% and by RCM in 72.2%, 55.6%, and 61.1% of cases, respectively. The detection of lymphocytes was more precise using RCM than LC-OCT in CTCL (p < 0.001). Dermal infiltration of medium-reflective cells was visible in 80% and 40% of CBCL cases by LC-OCT and RCM, respectively. Conclusions: Non-invasive imaging techniques may support clinicians in managing PCL; however, further studies are mandatory in this field.

Clinician's perspective on the diagnosis of primary cutaneous B-cell lymphoma

Of all cutaneous lymphomas, 25% are primary cutaneous B-cell lymphomas (PCBCLs). Of these, primary cutaneous follicle center lymphoma (PCFCL), primary cutaneous marginal zone B-cell lymphoma (PCMZL), and primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL-LT) are the most common subtypes. For the diagnosis of PCBCLs, a biopsy combined with immunohistochemistry and histological examination is the gold standard. PCBCLs are categorized into indolent or intermediate to aggressive subtypes based on their clinical behavior in a clinically oriented approach. PCDLBCL-LT has an aggressive course that spreads to extracutaneous sites in about 45% of cases, whereas PCFCL and PCMZL are indolent diseases. As a result, instrumental staging is advised for PCDLBCL-LT but not for extracutaneous disease after a diagnosis of PCMZL or PCFCL. Lastly, dermatoscopy may offer a novel diagnostic tool to improve the clinical recognition of various PCBCL subtypes when used in conjunction with a strong clinical suspicion.

Non-invasive Skin Imaging in Cutaneous Lymphomas

The diagnosis of cutaneous lymphomas is challenging and requires skin tissue for histology and immunophenotyping using immunohistochemistry and molecular studies. In recent years, the role of non-invasive imaging techniques has been described as part of the clinical assessment of cutaneous lymphoma lesions. Imaging modalities such as dermoscopy, reflectance confocal microscopy (RCM), and high frequency ultrasound (HFUS) have been shown to be very valuable in raising the clinical suspicion for lymphomas of the skin, and in distinguishing cutaneous lymphomas from inflammatory dermatoses such as lupus, psoriasis, or eczema. These non-invasive methods can be used to direct the clinician to the optimal biopsy site to maximize the histopathological results and minimize false negatives. These methods also have a potential place in monitoring treatment response. In this review we present a concise summary of the dermoscopic imaging, RCM, and HFUS features seen in cutaneous T-cell lymphomas (CTCL) and B-cell lymphomas (CBCL).

Facial Cutaneous Rosai-Dorfman Disease: Dermoscopic Findings with Successful Surgical Treatment

Rosai-Dorfman disease (RDD) is a rare non-Langerhans cell histiocytosis characterized by an accumulation of activated histiocytes within the affected tissues. It is a heterogeneous disease that includes the classical (nodal) and extra-nodal variants. The cutaneous form of the disease without the characteristic lymphadenopathy is rare and is often misdiagnosed as other dermatologic diseases. Misdiagnosis as lymphoproliferative and infectious diseases such as lymphoma and tuberculosis have been reported in the literature. Herein, we report a case of facial cutaneous RDD with successful surgical treatment. In addition, we provide dermoscopic findings and literature review as dermoscopy can be a useful adjuvant tool in the diagnosis of cutaneous RDD.

Cutaneous B-cell lymphomas: 2023 update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

Approximately one-fourth of primary cutaneous lymphomas are B-cell derived and are generally classified into three distinct subgroups: primary cutaneous follicle center lymphoma (PCFCL), primary cutaneous marginal zone lymphoma (PCMZL), and primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL, LT).

DIAGNOSIS

Diagnosis and disease classification is based on histopathologic review and immunohistochemical staining of an appropriate skin biopsy. Pathologic review and an appropriate staging evaluation are necessary to distinguish primary cutaneous B-cell lymphomas from systemic B-cell lymphomas with secondary skin involvement.

RISK-STRATIFICATION

Disease histopathology remains the most important prognostic determinant in primary cutaneous B-cell lymphomas. Both PCFCL and PCMZL are indolent lymphomas that infrequently disseminate to extracutaneous sites and are associated with 5-year survival rates that exceed 95%. In contrast, PCDLBCL, LT is an aggressive lymphoma with an inferior prognosis.

RISK-ADAPTED THERAPY

PCFCL and PCMZL patients with solitary or relatively few skin lesions may be effectively managed with local radiation therapy. While single-agent rituximab may be employed for patients with more widespread skin involvement, multiagent chemotherapy is rarely appropriate. In contrast, management of patients with PCDLBCL, LT is comparable to the management of patients with systemic DLBCL.

Cutaneous lymphomas in African American/Black patients: pitfalls and presentations

This review describes and highlights differences in clinical presentations of cutaneous lymphomas (CLs), particularly in darker skin types, i.e., Skin of Color (SOC). We illustrate differences in clinical features on physical exam that can be a diagnostic challenge and suggest ways to recognize and identify these conditions at an early stage through a high level of suspicion. The review includes a summary of the epidemiology of various CLs, specifically highlighting the presentation and incidence in African American/Black patients, where the data are available. We also include a discussion of adult HTLV-1-associated T-cell leukemia/lymphoma (ATLL) which, although a systemic T-cell lymphoma, may present with skin manifestations and mimic MF, other CTCL subtypes, or other inflammatory dermatoses. Finally, this review highlights the possible use of imaging modalities, such as dermoscopy and reflectance-confocal microscopy, in diagnosing and recognizing cutaneous lymphomas in patients with darker skin types.

Surgical, Dermatological and Morphopathological Considerations in the Diagnosis and Treatment of Cutaneous Lymphoproliferative Tumors, Primary CD4

Primary cutaneous lymphomas are a heterogeneous group of T-cell (CTCL) and B-cell lymphomas (CBCL) developing in the skin and without signs of extracutaneous disease at the time of diagnosis. The term "primary small/medium CD4+ T-cell lymphoma" was changed to "primary small/medium cutaneous CD4+ lymphoproliferative disorder" due to its indolent clinical behavior and uncertain malignant potential. This paper presents a rare case of primary cutaneous lymphoma with small to medium CD4+ T-cells. A 37-year-old patient presented with a tumor in the frontal region that had occurred approximately 8-9 months earlier. The tumor had a diameter of about 8-9 mm, well demarcated macroscopically, it was round in shape, about 6-7 mm high, pink in color, firm in consistency and painless during palpation. Surgical excision of the tumor was performed with a margin of safety of 8 mm and deep to the level of the frontal muscle fascia. The histopathological examination supported the diagnosis of cutaneous lymphoproliferation with a nodular disposition in the reticular dermis and extension around the follicular epithelia and sweat glands, composed mainly of dispersed medium-large lymphocytes. Additional immunohistochemical examination was requested. Immunohistochemical examination confirmed the diagnosis of "primary cutaneous CD4+ small/medium T-cell lymphoproliferative disorder." Patient monitoring was carried out through clinical dermatological controls at 3, 6, and 12 months. After one year, a cranio-cerebral MRI was performed. For the following 5 years, an annual dermatological examination accompanied by cranio-cerebral MRI, blood count, and pulmonary X-ray were recommended. Similarly to all solitary skin lesions, the prognosis is excellent in this case, the only treatment being surgical excision.

A Rare Case of Primary Cutaneous Follicle Center Lymphoma Mimicking Leprosy

Cutaneous B-Cell Lymphoma is a rare type of cutaneous lymphoma with a plethora of clinical manifestations ranging from macules, papules, nodules, or plaques. The lesions are often painless and certain subtypes such as the primary cutaneous follicle center lymphoma (PCFCL) are indolent. The disease is often misdiagnosed with other dermatoses including bacterial and fungal infections. Here we report a 55-year-old female patient with clinical manifestations resembling multibacillary leprosy that was then confirmed to be PCFCL through aid of dermoscopy and histopathology. The patient then undergone chemotherapy using the R-CHOP regiment which resulted in significant clinical improvement and no signs of metastases or extracutaneous involvement upon follow-up.

Dermatoscopy of nodular/plaque-type primary cutaneous T- and B-cell lymphomas: A retrospective comparative study with pseudolymphomas and tumoral/inflammatory mimickers by the International Dermoscopy Society

BACKGROUND

Limited data on dermatoscopy of nodular/plaque-type T-/B-cell primary cutaneous lymphomas (PCLs) is available.

OBJECTIVE

To describe dermatoscopic features of nodular/plaque-type PCLs, comparing them with those of clinical mimickers (pseudolymphomas, tumors, and inflammatory lesions) and investigating possible differences according to histologic subtypes.

METHODS

Participants were invited to join this retrospective, multicenter case-control study by submitting histologically/immunohistochemically confirmed instances of nodular/plaque-type PCLs and controls. Standardized assessments of the dermatoscopic images and comparative analyses were performed.

RESULTS

A total of 261 lesions were included (121 PCLs and 140 controls). Orange structureless areas were the strongest PCL dermatoscopic predictor on multivariate analysis compared with tumors and noninfiltrative inflammatory dermatoses. On the other hand, a positive association was found between PCLs and either unfocused linear vessels with branches or focal white structureless areas compared with infiltrative inflammatory dermatoses, whereas white lines were predictive of PCLs over pseudolymphomas. Differences in the vascular pattern were also seen between B- and T-cell PCLs and among B-cell PCL subtypes.

LIMITATIONS

Retrospective design and the lack of a dermatoscopic-pathologic correlation analysis.

CONCLUSION

Nodular/plaque-type PCLs display dermatoscopic clues, which may partially vary according to histologic subtype and whose diagnostic relevance depends on the considered clinical differential diagnoses.

Dermoscopic and trichoscopic features of primary cutaneous lymphomas - systematic review

Dermoscopy and trichoscopy are non-invasive methods used as auxiliary tools in diagnostics of different dermatoses. To date, no systematic review concerning the utility of dermoscopy and trichoscopy in the diagnostics of primary cutaneous lymphomas has been published. The aim of this study was to summarize the current state of knowledge on this topic based on systematic search of PubMed database and related references published before 8th of August 2020. Besides dermoscopic features, type of dermoscope, polarization mode, magnification, number of cases and histopathological correlation were analysed. A total of 34 records were included into the final analysis, evaluating 141 patients diagnosed with primary cutaneous T-cell lymphomas and 70 patients with primary cutaneous B-cell lymphomas. Most of the analysed records evaluated dermoscopic features (n = 206); trichoscopy was analysed in only 5 cases. Structures most commonly observed in classical mycosis fungoides (n = 108) were fine short linear vessels/linear vessels, spermatozoa-like vessels and orange-yellow patchy areas. In folliculotropic mycosis fungoides (n = 12), most frequently observed were comedonal lesions/comedo openings/central keratotic plugs and white halo around hair follicles/perifollicular accentuation. Primary cutaneous marginal zone B-cell lymphoma (n = 42) and primary cutaneous follicle centre lymphoma (n = 20) most commonly presented with salmon-coloured background and fine short/linear irregular/serpentine vessels. For other PCL, with less than 10 cases reported in the analysed records, details have been provided in the article. Most observations analysed in this systematic review rely on findings from case reports/case series (with the level of evidence V) and lack a control group. A few studies provided information concerning technical aspects of dermoscopic/trichoscopic examination. The role of dermoscopy/trichoscopy in diagnostics of cutaneous lymphomas requires further studies, especially in entities where dermoscopic features have been described in only single or a few cases. However, it seems that this practical, accessory tool in future may provide additional clues during clinical assessment.

Dermatological Considerations in the Diagnosis and Treatment of Marginal Zone Lymphomas

Primary cutaneous marginal zone lymphoma (PC-MZL) is a B-cell lymphoma arising in the skin. Although it is a rare disease, PC-MZL accounts for 20–40% of all primary cutaneous B-cell lymphoma in Western Countries. The aetiology and the pathogenesis of PC-MZL are poorly understood, as it generally lacks the chromosomal translocations most typically present in marginal zone lymphomas of other sites. The diagnosis of PC-MZL may be challenging, due to the rarity of the disease, and needs the competence of different professional figures, including the dermatologist and the pathologist. Furthermore, the management of the patient after the diagnosis is complex and involves the dermatologist, the haematologist, the surgeon, the radiotherapist and the radiologist. The aim of this review is to describe the clinical and histological findings for the diagnosis of PC-MZL, and the state of art for the management of the patient.

Cutaneous B-cell lymphomas: 2021 update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

Approximately one-fourth of primary cutaneous lymphomas are B-cell derived and are generally classified into three distinct subgroups: primary cutaneous follicle center lymphoma (PCFCL), primary cutaneous marginal zone lymphoma (PCMZL), and primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL, LT).

DIAGNOSIS

Diagnosis and disease classification is based on histopathologic review and immunohistochemical staining of an appropriate skin biopsy. Pathologic review and an appropriate staging evaluation are necessary to distinguish primary cutaneous B-cell lymphomas from systemic B-cell lymphomas with secondary skin involvement.

RISK-STRATIFICATION

Disease histopathology remains the most important prognostic determinant in primary cutaneous B-cell lymphomas. Both PCFCL and PCMZL are indolent lymphomas that infrequently disseminate to extracutaneous sites and are associated with 5-year survival rates that exceed 95%. In contrast, PCDLBCL, LT is an aggressive lymphoma with an inferior prognosis.

RISK-ADAPTED THERAPY

Both PCFCL and PCMZL patients with solitary or relatively few skin lesions may be effectively managed with local radiation therapy. While single-agent rituximab may be employed for patients with more widespread skin involvement, multi-agent chemotherapy is rarely appropriate. In contrast, management of patients with PCDLBCL, LT is comparable to the management of patients with systemic DLBCL.

Primary Cutaneous B-Cell Lymphomas: An Update

Primary cutaneous B-cell lymphomas (PCBCLs) comprise a group of extranodal B-cell non-Hodgkin lymphomas B-cell derived, which primarily involve the skin without evidence of extracutaneous disease at the time of diagnosis. They include ~25% of all cutaneous lymphomas and are classified in three major subgroups (World Health Organization (WHO) 2017): primary cutaneous marginal zone lymphoma (PCMZL), primary cutaneous follicle-center cell lymphoma (PCFCL), and diffuse large B-cell lymphoma, leg type (PCDLBCL, LT). This classification also includes some less common entities such as intravascular large B-cell lymphoma. Recently, WHO-EORTC added Epstein-Barr virus positive (EBV+) mucocutaneous ulcer, as a new provisional distinct entity, to cutaneous B-cell lymphomas. PCBCLs are classically characterized by patches, plaques, or nodules showing great variability for color, shape, and location. Diagnosis requires histological examination with immunohistochemical staining. In general, therapeutic options depend on the exact histological and immunohistochemical classification, disease presentation, and risk assessment. PCMZL and PCFCL are considered indolent lymphomas with a good prognosis and are associated with 5-year disease-specific survival ≥ 95%. In contrast, PCDLBCL, LT is considered an aggressive lymphoma with a survival rate in 5 years of lower than 60%. Patients with a solitary lesion or limited lesions in a single anatomical site require different treatments as compared to patients with generalized lesions or refractory disease or extracutaneous involvement. Therapeutic choice includes observation, local, or systemic therapy based on histology and disease extension. Patient management is multidisciplinary, including dermatologists, pathologists, hemato-oncologists, and radiation oncologists.

Unusual Clinical Presentation of a Primary Cutaneous Follicle Center Lymphoma on the Scalp of a Middle-Aged Female: Case Report and Review of the Literature

Primary cutaneous follicle center lymphoma (PCFCL) is a rare type of indolent, low-grade cutaneous B-cell lymphoma with an excellent prognosis. It usually presents with erythematous nodules and plaques on the head, neck, or back. The diagnosis is primarily based on histopathology, immunohistochemistry, and molecular studies. We describe a case of PCFCL causing a well-defined alopecic atrophic patch. The patch developed in the area of a large subcutaneous nodule that regressed after treatment with rituximab infusion. We hypothesize that the alopecia could have been caused by pressure.

Dermoscopy of the Month: Dermoscopy of Primary Cutaneous B-Cell Lymphoma

Primary cutaneous B- cell lymphomas (PCBLs) are B-cell malignant neoplasms that originate in the skin, and have no extracutaneous manifestations of disease at the time of diagnosis. PCBLs are classified into three main types: primary cutaneous marginal zone lymphoma (PCMZL), primary cutaneous follicle center lymphoma (PCFCL), and primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL- LT). Dermoscopic characterization of PCBLs has been limited and dermoscopy may help to augment the clinical recognition of PCBLs with the most common dermoscopic findings of salmon colored areas and serpentine vessels. Recognition of dermoscopic features of primary cutaneous B- cell lymphomas can improve the early diagnosis of these tumors and their proper management.

Dermoscopy of Lymphomas and Pseudolymphomas

Primary cutaneous lymphomas are a heterogeneous group that includes 2 main groups of primary T- and B-cell lymphomas, which can involve the skin with distinct variability in clinical presentation, histopathology, immunophenotypes, molecular signature, and prognosis. The authors describe the most frequent clinical forms of cutaneous lymphomas and their dermoscopic features. Even if the diagnosis of these entities is still based on a cellular level and the literature on dermoscopy in cutaneous lymphomas is limited and, for several entities it is based only on single case reports/case series, we think that know how they appear also in dermoscopy can be useful for helping in the clinical diagnosis.

Alternative uses of dermoscopy in daily clinical practice: An update

Dermoscopy is a noninvasive diagnostic tool that is currently being used for neoplastic skin lesions, several inflammatory and infectious diseases, and skin appendage disorders. As the clinical applications of dermoscopy beyond pigmented lesions are constantly increasing, the aim of this article is to provide an update on this topic. This comprehensive review substantiates how several diseases may show peculiar dermoscopy features so as to enhance the diagnosis and avoid (in selected cases) unnecessary histologic confirmation. In other cases, dermoscopy features may be shared with other conditions, with the advantage of narrowing down the differential diagnosis by ruling out those dermatoses with similar clinical aspect but different dermoscopic presentation.

Methotrexate-Associated Lymphoproliferative Disorder: Dermoscopic Features

Methotrexate-related lymphoproliferative disorder (MTX-LPD) is a rare disorder caused by long-term MTX therapy for autoimmune diseases. There has been no report of the dermoscopic features of MTX-LPD to date. A 64-year-old female presented with a slightly elevated indurated erythematous plaque with scales on her right thigh. The patient had been treated for rheumatic arthritis with MTX and prednisolone for more than 15 years, and 18 mg/week MTX without prednisolone had been administered in the last year. Dermoscopy revealed dotted vessels and glomerular vessels on pink homogeneous areas and multiple surface scales. Enhanced computed tomography showed multiple nodules and lymphadenopathies at the mediastinum and axillae. Histopathological examination revealed telangiectasia in the superficial dermis. Atypical lymphoid cells were scattered in the whole dermis and subcutaneous tissue. A perivascular infiltrate of atypical lymphocytes and histiocytoid cells partially destroyed the vessel walls. Epstein-Barr virus in situ hybridization showed a positive result. The cessation of MTX reduced the erythematous plaque, and lymphadenopathies at the neck, mediastinum, and axillae were not palpable. We discuss the relevance of these dermoscopic and histopathological features. The accumulation of such cases will reveal the dermoscopic features of MTX-LPD and the utility of dermoscopy for the diagnosis of MTX-LPD.