Successful treatment of cyclosporine-A-resistant cytophagic histiocytic panniculitis with tacrolimus

Clinicopathological Characteristics and Outcome of Cytophagic Histiocytic Panniculitis: A Single-Center, Retrospective Study

Background

Cytophagic histiocytic panniculitis (CHP) is a rare panniculitis associated with systemic features characterized by the infiltration of subcutaneous adipose tissue by benign-appearing T lymphocytes and phagocytic histiocytes, mimicking hemophagocytic lymphohistiocytosis (HLH) and subcutaneous panniculitis-like T-cell lymphoma (SPTCL).

Purpose

To establish the clinicopathological features and response to treatment of CHP and evaluate the prognosis of patients and guide therapy based on the current state of knowledge.

Material and Methods

Clinical, laboratory, histopathological, and outcome data of 12 patients with CHP were retrospectively collected between 2009 and 2022.

Results

All the patients presented with plaques or nodules, mostly located in the lower extremities (11/12). Fewer cases involved systemic symptoms (9/12) and laboratory abnormalities (6/12), and none were positive for serum Epstein-Barr virus (EBV)-DNA. Histopathological examination revealed mixed septal and lobular inflammatory infiltration of histiocytes and lymphocytes. Large or atypical lymphocytes were rarely present (2/12). In some patients, varying proportions of plasma cells, neutrophils, and eosinophils were observed. The extent of histocytophagy was mild (9/12), moderate (2/12), and severe (1/12). HLH was not observed in any of our cases, none of which were fatal.

Conclusion

The uniqueness of our study lies in the presence of neutrophil-rich dermal and subcutaneous infiltrates, associated with connective tissue disorders (CTD) and streptococcal infections. Our study reveals that EBV-negative CHP tends to a better prognosis than previously research, filling the gap in the much-needed details of CHP in the Chinese population. Moreover, CHP may present as a reactive process in combined primary diseases; further studies are required to validate these findings.

Cytophagic Histiocytic Panniculitis and Kikuchi-Fujimoto-Like Lymphadenitis in a Patient With Systemic Lupus Erythematosus

A 54-year-old African American male with systemic lupus erythematosus and chronic alcoholic hepatitis presented with recurrent fever, pancytopenia, transaminitis, weight loss, and widespread violaceous tender plaques. Skin biopsy revealed hemophagocytic histiocytes leading to a diagnosis of cytophagic histiocytic panniculitis in the setting of lupus panniculitis. During workup, an axillary lymph node biopsy mimicked Kikuchi-Fujimoto's disease. Treatment with tapering high-dose glucocorticoids, mycophenolate mofetil, and hydroxychloroquine induced remission of the disease. We believe the comorbid conditions of Kikuchi-Fujimoto-like pathology and cytophagic histiocytic panniculitis have not been documented in the literature to date in a patient with systemic lupus erythematosus.