[P-10] Subcutaneous panniculitis-like T-cell lymphoma in paediatric population: a report of two cases and literature review
Anh Thu Phan Dang1, Mai Anh Nguyen Hoang2 and Tuan Dung Vu1
- Department of Pathology, Faculty of Medicine, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City, Vietnam
- Department of Haemato-Oncology, City Children's Hospital, Ho Chi Minh City, Vietnam
Background: Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare entity of mature αβ cytotoxic T-cells commonly found in young adults. We reported two cases of SPTCL occurring in the paediatric age group.
Case Presentation: Two boys (12 and 14 years old) were admitted to the hospital with a fever of unknown origin for over one month. They had multiple painless erythematous subcutaneous plaques and deep-seated skin nodules, ranging from 0.5 – 8 cm in diameter. The evidence of lupus erythematosus was not found. The skin biopsies showed the infiltration of a composition of small- to medium-sized lymphoid cells and histiocytes in the subcutaneous adipose tissue with the background of fat necrosis, karyorrhexis and histiocytes; which spared the dermis, epidermis and septa between adipose lobules. Lymphocytes rimmed adipocytes and exhibited nuclear hyperchromasia and contour irregularity. By immunohistochemistry, these lymphoid cells showed strong positivity for CD3, CD8 and negativity for CD4, CD56. A hotspot of Ki-67 expression was helpful for the diagnosis of SPTCL. Bone marrow involvement was not found in both cases. However, one patient presented with an aggressive clinical course with the presence of haemophagocytic lymphohistiocytosis.
Discussion and Conclusion: SPTCL diagnosis is challenging, especially in the early stages, as the symptoms may mimic other conditions like eczema or lupus erythematosus panniculitis. Therefore, a thorough clinical investigation and histology examination are helpful in diagnosis. Lymphocytes rim adipocytes and immunohistochemical expression for mature αβ cytotoxic T-cells can be a clue for SPTCL diagnosis. High Ki-67 expression is also concerning for lymphoma.