Inflammatory Morphea with T Cell Receptor Gamma Gene Clonality.
Stephen H Olsen, Limin Yu, Joseph Willman, Kojo Elenitoba-Johnson, Linglei Ma. University of Michigan, Ann Arbor
Background: Inflammatory morphea has been described as a histologic as well as clinical simulant of interstitial mycosis fungoides (MF). Specifically, in early inflammatory morphea, inflammation is in a prominently interstitial pattern with minimal sclerosis, such that significant overlaps with interstitial MF may exist. In clinical practice, we encountered two cases of inflammatory morphea which demonstrated not only histological and clinical similarities with interstitial MF but also T-cell receptor gamma (TCRg) gene clonality by gene rearrangement (GR) analysis. With time, both cases evolved into clear-cut morphea. Here, we performed retrospective TCRg GR studies on more cases of morphea to assess GR analysis as a potential pitfall.
Design: A total of 21 cases of morphea were identified through our pathology information system, and diagnoses were confirmed by microscopic review and correlation with clinical information. Formalin fixed paraffin embedded tissue blocks from these cases were submitted to TCRg GR analysis by polymerase chain reaction (PCR) and interpreted in standard fashion.
Results: Patients ranged from 25 to 77 years of age (median 46 years), and were predominantly females (2:1). The majority of specimens came from truncal locations, such as breast, chest, abdomen and back. Based on the degree of sclerosis, these 21 cases were divided into two groups: 9 cases of group A (minimal sclerosis with prominent interstitial infiltrate) and 12 cases of group B (well-developed sclerosis with variable perivascular or nodular infiltrate). The amount of interstitial dermal inflammation appeared inversely related to the degree of sclerosis. Four cases were positive for clonal TCRg gene by PCR. The remaining 17 cases were negative for clonality. The positive cases involved 3 females and 1 male, ranging in ages from 41 to 61 years old. The specimens were taken from abdomen (2), breast (1) and upper chest (1). Histologically, Three cases were classified as group A and 1 as group B.
Conclusions: A small subset of inflammatory morphea cases may show TCRg gene clonality. Therefore, the distinction between early inflammatory morphea and interstitial MF should not be exclusively based on the result of TCRg GR study result.
Definitive distinction of inflammatory morphea from interstitial MF will depend upon clinical as well as pathologic evolution of the disease over time with the findings of more classic lesions.
Wednesday, March 2, 2011 1:00 PM
Poster Session VI # 104, Wednesday Afternoon