Dermoscopic characterization of cutaneous lymphomas: a pilot survey.

BACKGROUND: While substantial dermoscopic analysis of melanocytic lesions has been performed, dermoscopic characterization of cutaneous lymphoid proliferations has been limited. Cutaneous lymphoma, particularly early mycosis fungoides (MF) and its variants, is often challenging to clinically and pathologically distinguish from inflammatory processes of the skin. This study aimed to survey the dermoscopic findings of cutaneous lymphomas and to discern whether any patterns might potentially serve as specific signatures. METHODS: Fifteen patients with an established diagnosis of cutaneous lymphoma were prospectively recruited and seen in the university multidisciplinary cutaneous lymphoma program with MF, an MF- variant, CD30-positive lymphoproliferative disorder, or cutaneous B-cell lymphomas and were included in our study. Dermoscopic findings, histologic features, clinical characteristics, and demographic data were analyzed. RESULTS: Patch stage MF was characterized by interconnected white structureless patches encircling small fine linear vessels, yielding an overall trabeculated to fenestrated pattern under dermoscopy. Corresponding histopathologic findings for these patterns included epidermotropism, atypical pleomorphic cells, and lichenoid infiltrates. Folliculotropic mycosis fungoides (FMF) was characterized by folliculocentric erosions surrounded by dotted and fine linear vessels, loss of terminal follicles, comedo-like openings, and interconnected regular-appearing structureless patches. Corresponding histopathologic findings in these FMF cases were typical of FMF. Notably, these changes were not appreciated in lymphomatoid papulosis. Primary cutaneous follicle center B cell lymphoma showed crystalline structures and vascular pseudopods. CONCLUSIONS: Cutaneous lymphomas appear to demonstrate characteristic dermoscopic patterns, reflective of the specific lymphoma type and its corresponding histopathology, which have not been seen in inflammatory skin conditions, such as psoriasis and eczematous dermatitis.

Follicular lymphomatoid papulosis with follicular mucinosis: a clinicopathologic study of 3 cases with literature review and conceptual reappraisal.

Lymphomatoid papulosis (LyP), characterized by recurring, waxing and waning, cutaneous papulonodules, is increasingly recognized to represent a heterogeneous collection of pathologically dissimilar subtypes. Recently, a follicular LyP variant was proposed, featuring folliculotropism. Folliculotropism by atypical lymphocytes is conventionally associated with follicular mucinosis and mycosis fungoides (MF), and review of the literature suggests co-occurrence of folliculotropism and follicular mucinosis in LyP to be rare, with only 3 cases identified to date. Herein we describe 3 additional cases, each manifesting a typical LyP clinical picture, with the additional element of folliculotropism and follicular mucinosis on pathology. These cases suggest that LyP should be considered alongside MF in the differential diagnosis of follicular mucinosis with accompanying atypical lymphocytic infiltration. As LyP can occur with other lymphoproliferative disorders such as MF, the finding of follicular mucinosis in LyP may further represent a conceptual intersection between the 2 disease processes.

Ulcerated Spitz nevus masquerading as a juvenile xanthogranuloma.

We report a case of ulcerated atypical Spitz nevi that demonstrated a yellow to light orange background under dermoscopy, which can be seen in juvenile xanthogranuloma (JXG) and is referred to as the "setting sun" appearance. This yellow to orange appearance was due to serous crusting and not histiocytic infiltration, which is seen in JXG. This case highlights overlapping dermatoscopic features between the two skin lesions and polymorphous vascular structures, which are unique to atypical Spitz nevi.

Cutaneous myeloid sarcoma: natural history and biology of an uncommon manifestation of acute myeloid leukemia.

We conducted a retrospective study of patients with cutaneous myeloid sarcoma, from 2 tertiary care institutions. Eighty-three patients presented, with a mean age of 52 years. Diagnosis of myeloid sarcoma in the skin was difficult due to the low frequency of myeloperoxidase and/or CD34+ cases (56% and 19% of tested cases, respectively). Seventy-one of the 83 patients (86%) had ≥ 1 bone marrow biopsy. Twenty-eight (39%) had acute myeloid leukemia with monocytic differentiation. Twenty-three had other de novo acute myeloid leukemia subtypes. Thirteen patients had other myeloid neoplasms, of which 4 ultimately progressed to an acute myeloid leukemia. Seven had no bone marrow malignancy. Ninety-eight percent of the patients received chemotherapy, and approximately 89% died of causes related to their disease. Cutaneous myeloid sarcoma in most cases represents an aggressive manifestation of acute myeloid leukemia. Diagnosis can be challenging due to lack of myeloblast-associated antigen expression in many cases, and difficulty in distinguishing monocyte-lineage blasts from neoplastic and non-neoplastic mature monocytes.

Use of classic and novel immunohistochemical markers in the diagnosis of cutaneous myeloid sarcoma.

Cutaneous myeloid sarcoma is often challenging to diagnose based solely upon histopathological features. Although immunohistochemistry can aid in its diagnosis, specific markers have not been clearly identified. We evaluated the utility of immunohistochemical markers in 57 cutaneous myeloid sarcoma cases. In addition to classical markers (CD117, CD163, CD34, myeloperoxidase and lysozyme), we used CD33 and CD14, recently described markers in paraffin-embedded tissue samples, and Kruppel-like factor 4 (KLF-4), a novel monocytic marker. Our results show that lysozyme was expressed in 91%, CD33 in 60%, myeloperoxidase in 54%, CD34 in 39% and CD117 in 36% of cases. An antibody panel that included lysozyme, CD117 and CD33 identified all cases. The monocytic markers CD14, KLF-4 and CD163 were expressed in 60, 58 and 40% of all cases, respectively. CD14 and KLF-4 expression was significantly more common in cases with monocytic differentiation. CD14 is the single most sensitive and specific marker for monocytic differentiation (79 and 80%). Although KLF-4 in isolation is relatively insensitive (50 and 87%), it enhances sensitivity in detecting monocytic cutaneous myeloid sarcoma when combined with CD14. Our results indicate that in addition to classical immunohistochemical markers, targeted use of newer antibodies, including CD33, CD14 and KLF-4 is useful in the diagnosis of cutaneous myeloid sarcoma and in the detection of monocytic differentiation.