Dermoscopy can be a useful tool to help clinicians in the diagnosis of cutaneous B-cell lymphomas.
A 61-year-old man presented with an irregularly growing erythematous plaque measuring 28 × 35 mm, which had appeared on the left thigh a few months before ( Figure 1A ). He was otherwise healthy and could not recall an arthropod bite or a trauma in the same area. He was not taking any drugs and did not report weight loss, fever, or night sweating. The physical examination was normal. Upon polarized noncontact dermoscopy, we observed a diffuse salmon-colored area with focally white areas ( Figure 1B ).
Figure 1 .
(A) Irregular erythematous plaque on the left thigh. (B) Polarized noncontact dermoscopy: A diffuse salmon-colored area on the background, together with focally white areas (marked with black arrows) and white circles (marked with asterisks). [Copyright: ©2019 Biondo et al.]
The lesion was totally excised with differential diagnosis of granulomatous dermatosis, amelanotic melanoma, cutaneous lymphoma, sarcoma, or metastasis. Histopathology showed a dense nodular dermal lymphocytic infiltrate extending to the subcutaneous fat composed of reactive lymphoid follicles surrounded by a diffuse infiltrate composed by small to medium sized cells (marginal zone cells). In addition, plasma cells (at the margins of the infiltrate), lymphoplasmacytoid cells, small reactive lymphocytes, and occasional eosinophils were observed.
A clear-cut grenz zone between the infiltrate and the epidermis was present ( Figure 2 ). Neoplastic cells stained positive for CD20 and CD79a; cells stained negative for Bcl-6, Bcl-2, CD5, and CD10; reactive T lymphocytes were CD3+. A monoclonal expression of kappa chain was found. Further complete staging investigations were negative for nodal or systemic involvement. Following WHO criteria [ 1 ] , primary cutaneous marginal zone lymphoma (PCMZL) was diagnosed.
Figure 2 .
(A) Below a clear-cut grenz zone in the papillary dermis, there is a dense nodular dermal lymphocytic infiltrate composed of reactive lymphoid follicles surrounded by small to medium-sized cells (marginal zone cells). No dilated vessels in the papillary dermis are seen; areas of reactive fibrosis in the dermis are present (hematoxylin and eosin [H&E], ×20). (B) Focally, the grenz zone is reduced due to patchy, nodular, more superficial infiltrate in the papillary dermis (H&E, ×100). (C) Marginal zone cells, plasma cells, lymphoplasmacytoid cells, and slight increase of vessels within the infiltrate (H&E, ×200). (D) Plasma cells and lymphoplasmacytoid cells (H&E, ×400). [Copyright: ©2019 Biondo et al.]
PCMZL is a low-grade malignant primary cutaneous B-cell lymphoma (PCBCL). Clinically, patients present with solitary or multiple, asymptomatic, rarely ulcerative pink-violet to red-brown papules, plaques, and nodules localized preferentially on the extremities or trunk. Mascolo et al. described the dermoscopic features of 10 PCBCL cases, observing white circles with a salmon-colored area in 9/10 cases, scales in 7/10 cases, and arborizing vessels or a polymorphous vascular pattern in 5 and 2 cases, respectively [ 2 ] . Piccolo et al. also described the same features in 2 additional patients [ 3 ] . Geller et al. expanded the study, examining 58 dermoscopic images of PCBCLs, and reported a salmon-colored area (79.3%) and prominent blood vessels (77.6%), mostly of serpentine (linear-irregular) morphology (67.2%) [ 4 ] . Ghahramani observed spermatozoa-like structures, orange-yellowish patchy areas, crystalline structures, and pseudopod-like vessels in primary cutaneous follicle center lymphoma, but not in PCMZL [ 5 ] . These findings are summarized in Table 1 .
Dermoscopic, Clinical, and Histological Features of PCBCLs Reported in the Literature
Our observation confirms that a salmon-colored area upon dermoscopy is typical even if not exclusive of PCBCL. In fact, it brings to mind the orangish-yellowish areas observed in granulomatous dermatoses such as sarcoidosis, lupus vulgaris, and granulomatous rosacea, where also linear branching vessels are seen [ 6 , 7 ] , while granuloma annulare shows peripheral structureless reddish-yellowish-orange areas with variable blurry vessels [ 8 , 9 ] . It is difficult to correlate the salmon color of PCBCL with pathology; an explanation could reside in the increased vascularization inside the dense nodular neoplastic lymphoid infiltrate in the mid and deep dermis ( Figure 2C ). White areas probably correlate with areas of reactive fibrosis in the dermis or might correlate with focally reduced grenz zone due to patchy, nodular, more superficial infiltrate in the papillary dermis ( Figure 2B ). Recently, pseudopod-like vessels have been correlated with dilated ectatic vessels surrounding the neoplastic follicles [ 5 ] .
As further dermoscopic differential diagnosis, amelanotic melanoma shows dotted vessels, linear-irregular vessels, hairpin-irregular vessels, serpentine vessels, or a combination of them (polymorphic vessels); also milky-red areas can be frequently visualized [ 10 ] . Contrary to previous experiences [ 2 , 3 ] , in our patient prominent vessels with serpentine morphology were not observed. Also on dermoscopic-pathologic correlation, no dilated vessels were observed in the superficial dermis; prominent blood vessels have been correlated with neoangiogenesis, a phenomenon that in our case probably did not occur yet in the superficial dermis because it might be correlated with a different stage of the disease.
In conclusion, a salmon-colored area and white areas on dermoscopy might be suggestive, even if not unique, of PCBCL, supporting clinicians in recognizing primary lesions and recurrences [ 11 ] , moreover identifying correct site of biopsy.
- Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) Cook JR, Isaacson PG, Chott A, et al. Swerdlow SH, Campo E, Harris NL, et al. WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues.2017;:259-262.
- Dermoscopy pattern, histopathology and immunophenotype of primary cutaneous B-cell lymphoma presenting as a solitary skin nodule Mascolo M, Piccolo V, Argenziano G, et al. Dermatology.2016;232(2):203-207.
- Dermoscopy of primary cutaneous B-cell lymphoma (PCBCL) Piccolo V, Mascolo M, Russo T, Staibano S, Argenziano G. J Am Acad Dermatol.2016;75(4):e137-e139.
- Dermoscopy and the diagnosis of primary cutaneous B-cell lymphoma Geller S, Marghoob AA, Scope A, Braun RP, Myskowski PL. J Eur Acad Dermatol Venereol.2018;32(1):53-56.
- Dermoscopic characterization of cutaneous lymphomas: a pilot survey Ghahramani GK, Goetz KE, Liu V. Int J Dermatol.2018;57(3):339-343.
- Orange color: a dermoscopic clue for the diagnosis of granulomatous skin diseases Bombonato C, Argenziano G, Lallas A, Moscarella E, Ragazzi M, Longo C. J Am Acad Dermatol.2015;72(1 Suppl):S60-S63.
- Lupus vulgaris: a new look at an old symptom—the lupoma observed with dermoscopy Brasiello M, Zalaudek I, Ferrara G, et al. Dermatology.2009;218(2):172-174.
- Dermoscopy of granuloma annulare: a clinical and histological correlation study Errichetti E, Lallas A, Apalla Z, Di Stefani A, Stinco G. Dermatology.2017;233(1):74-79.
- Yellow and orange in cutaneous lesions: clinical and dermoscopic data Bañuls J, Arribas P, Berbegal L, DeLeón FJ, Francés L, Zaballos P. J Eur Acad Dermatol Venereol.2015;29(12):2317-2325.
- How to diagnose nonpigmented skin tumors: a review of vascular structures seen with dermoscopy, part I: melanocytic skin tumors Zalaudek I, Kreusch J, Giacomel J, Ferrara G, Catricalà C, Argenziano G. J Am Acad Dermatol.2010;63(3):361-374.
- Dermoscopy of cutaneous lymphoproliferative disorders: where are we now? Piccolo V, Russo T, Agozzino M, et al. Dermatology.2018;234(3–4):131-136.