[515] Histopathologic Features of Mycosis Fungoides

Evan L Kulbacki, Puja K Puri. Duke University Medical Center, Durham, NC

Background: Mycosis fungoides (MF) is a distinct clinicopathologic peripheral T-cell lymphoma. The histopathology of MF is not unique. In fact, its features can significantly overlap with benign dermatitis. Herein, we describe the histologic features of seventy-three cases of MF (two are folliculotropic) and compare those features to a similar number of cases spongiotic dermatitis and psoriasiform dermatitis.
Design: The Duke Pathology clinical database was searched for cases with the diagnosis of “mycosis fungoides”. After the patients were identified, those with a concurrent, positive T-cell gene rearrangement study (TCRGR) were selected. Seventy-three biopsies met the predetermined inclusion criteria. Fifteen histologic parameters on each biopsy were evaluated including the following: parakeratosis, ulceration, dyskeratosis, civatte bodies (intraepidermal necrotic keratinocytes), spongiosis, Langerhan cell collections, interface dermatitis, fibroplasia, lichen simplex chronicus changes (LSC), mast cells, eosinophils, neutrophils, margination of neutrophils, colloid bodies (dermal) and dermal edema. Spongiosis was graded on a spectrum from absent to severe, while the cellular infiltrates were either absent, <10%, or >10%. A similar number of biopsies with the descriptive diagnosis of spongiotic dermatitis (SD) and psoriasiform dermatitis (PD) were analyzed using identical criteria. The histopathologic characteristics of the three groups were calculated to determine if distinct characteristics exist.
Results: There were several histologic features that were more or less common in MF than the other two groups. Langerhan cell collections were almost 10X more common in SD and PD than in MF (MF-1.4%, SD-12.3%, PD-18.4%). LSC changes were most characteristic of PD (MF-5.5%, SD-6.8% and PD-46.1%). Colloid bodies were present more than 10X more frequently in MF than in SD and PD (MF-19.2%, SD-1.4% and PD-1.3%). Neutrophils in the dermis were observed less frequently in MF (MF-18.9%, SD-54.8% and PD-50%). Approximately 50% of the MF cases in our study contained eosinophils. Interestingly spongiosis was present in 64.4% of MF biopsies, in contrast to SD-100% and PD-82.1%.
Conclusions: This series noted an association of certain histologic features and MF, namely: the presence of colloid bodies and the absence of Langerhan cell collections, neutrophils in the dermis and LSC changes favored a diagnosis of MF. Spongiosis, although less frequently observed in MF as compared to SD and PD, was still present in almost 2/3 of the cases in our series. Finally, almost 50% of the MF cases contained eosinophils.
Category: Dermatopathology

Tuesday, March 20, 2012 9:30 AM

Poster Session III # 104, Tuesday Morning

 

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