To investigate the characteristics of subcutaneous panniculitis-like T cell lymphoma (SPTCL) in order to facilitate prompt identification and proper treatment of this rare and heterogeneous disease entity.
For 8 patients who had been misdiagnosed as rheumatic diseases but eventually confirmed as SPTCL though pathology and immunohistochemistry, a retrospective chart review was made with regard to their clinical symptoms, laboratory test results, pathological features, responses to therapy as well as outcomes.
These 8 patients with a male to female ratio of 1:1 were initially misdiagnosed as a variety of rheumatic diseases such as erythema nodosa, nodular panniculitis, systemic vasculitis, etc. The period from the onset of symptoms to the confirmation of diagnosis as SPTCL was 28.6 months on average (range, 4 - 84 months). All the cases presented with multiple subcutaneous nodules, plaques or tumors which involved various anatomic sites including the head and neck, the trunk, and the extremities. Fever was the most frequently accompanying symptom (7/8), followed by lymphadenopathy (4/8), hepatomegaly (3/8), splenomegaly (3/8). Hemophagocytic phenomenon was seen in 3 cases. A total of 22 times of biopsy involving multiple anatomic sites were performed on these 8 cases with 2.75 times on average (range, 1 - 5 times). All cases demonstrated a dense lymphoid infiltrate with significant cellular heteromorphism located in the subcutaneous tissue. CD(3) was positive in the majority of the cases. Immunostaining for gammadeltaTCR was positive in one case. The anti-rheumatic therapy including steroids and immunosuppressants administered before the identification of SPTCL attained minimal therapeutic effect. In contrast, 6 cases gained partial response after chemotherapy except that the other 2 cases died of fatal pulmonary infiltration and subsequent infection.
SPTCL is a rare and heterogeneous entity which is unseldomly misdiagnosed as rheumatic disease. The anti-rheumatic therapy including steroids and immunosuppressants can attain minimal therapeutic effect. Early identification by means of histology and immunohistochemistry as well as immunostaining for PCR is critical for proper treatment.