Dermoscopy of primary cutaneous B- and T-cell lymphomas and pseudolymphomas presenting as solitary nodules and tumors: a case-control study with histopathologic correlation.

BACKGROUND: Primary cutaneous lymphomas (PCLs) and pseudolymphomas presenting as single pink-red nodules/tumors are highly unspecific and include a wide differential diagnosis. OBJECTIVE: To describe the dermoscopic characteristics of PCL/pseudolymphoma. METHODS: In this retrospective, case-control study, we evaluated the dermoscopic features of patients with solitary PCL/pseudolymphoma tumors and compared them to a control group of non-lymphomatous, nonpigmented, solitary tumors (e.g., basal cell carcinoma, amelanotic melanoma, etc). RESULTS: We included 14 patients with PCL/pseudolymphomas and 35 controls. T-cell and B-cell lymphoma proportions were 28.6% (n = 4) and 71.4% (n = 10), respectively. Compared to controls, most lymphomas presented dermoscopically with orange color (71.4% vs. 14.2%, P < 0.001), follicular plugs (85% vs. 2.8%, P < 0.001), and as  organized lesions (85% vs. 31.4%, P = 0.001). Coexistence of orange color and follicular plugs had an odds ratio (OR) of 2.8 (P < 0.001), highly suggestive of PCL . The kappa index for independent observers was 0.66, 0.49, 0.43 for orange background, follicular plugs, and organized lesion, respectively. Histopathologic correlation was performed in six PCL cases and showed dense diffuse and perifollicular lymphocytic infiltrate in all cases and keratin plugs in five of six cases, possibly correlating with the orange color and the follicular plugs, respectively. CONCLUSION: Primary cutaneous lymphomas/pseudolymphomas present with characteristic dermoscopic findings irrespective of immunohistochemical subtype.

Hidrocistoma apocrino desafío dermatoscópico / Apocrine hydrocystoma dermoscopic challenge

Los hidrocistomas apocrinos son lesiones quísticas benignas. Clínicamente se caracterizan por ser nódulos quísticos claros o traslucidos, solitarios, en forma de cúpula, con superficie lisa. En la mayoría de los casos la localización suele ser alrededor del ojo, particularmente lateral al canto externo. Suelen ser asintomáticos, de crecimiento lento pudiendo llegar a 10 mm de diámetro o más. Presentamos un caso de un paciente con un hidrocistoma apocrino variante pigmentada.

Apocrine hydrocystomas are benign cystic lesions, clinically characterized by being clear or translucent cystic nodules, solitary, domeshaped, with a smooth surface. In most cases the location is usually around the eye, particularly lateral to the outer edge. They are usually asymptomatic, slow growing and can reach 10 mm in diameter or more. We present a case of a patient with a pigmented variant apocrine hydrocystom