A case of peripheral T-cell lymphoma unspecified involving subcutaneous tissue

Abstract

A 36-year-old man presented with a 3-year-old red-brown plaque with subcutaneous nodules on his left thigh. Although a similar lesion was observed on his right thigh 3 years earlier, it spontaneously disappeared 1 year later. However, the lesion on the left thigh was growing larger. Histologically, the lesion showed a diffuse and dense infiltration of atypical lymphocytes extending from the superficial dermis to the subcutaneous tissue. Severe lobular panniculitis, composed of small- and medium-sized atypical lymphocytes and large normal histiocytes, was observed in the subcutaneous adipose tissue. Immunohistochemical studies revealed a post-thymic T-cell phenotype. A genetic analysis demonstrated a rearrangement of the T-cell receptor chain gene. The left skin lesion also gradually disappeared after skin biopsy without therapy, and he continues to be in remission.

Case Details

Disease Location

Subcutaneous nodules on his left thigh inguinal ln

Personal Characteristics

36 -year-old male

Clinical Characteristics

3 year history of pigmented subcutaneous nodules on his left thigh at a previous clinic, the same lesion was found on the right thigh CT scan reveal neither internal organ involvement nor nodal lesions. Routine lab work was also normal clinical eam found a red-brown plaque on his left thigh with 3 elastic, hard, and ill-defined subcutaneous nodules measuring approx 5, 25, and 44 mm in diameter, a CT scan showed deep left inguinal lymph node swelling with detached subcutaneous nodules lab tests revealed almost all parameters were within normal limits except for the moderate presence of eosinophilia (1480 microliters) and high values of soluble interleukin-2 receptor (868 u/ml). Human t-cell leukemia virus was seronegative incisional skin biopsy revealed perivascular and interstitial dense infiltrate which extended from the superficial dermis to the deep dermis which was composed of small-to-medium sized lymphocytes and large normal histiocytes that were mingled with eosinophils. The lymphocytes had a hyperchromatic and slightly pleomorphic nucleus without abnormal mitotic figures. Additional skin biopsy revealed that normal fat tissue had been replaced by the infiltrate and necrobiotic collagen in the adipose tissue with a low power appearance that mimicked lobular panniculitis. Karyorrhexis and fat necrosis were absent, phagocytic cells containing cellular debris were found, erythrocytophagia was no detected immunostaining showed an antibody against CD3 stained most of the lymphocytes in the entire dermis and subcutaneous tissue. Less than 5% of the lymphocytes showed a postiive reaction for CD20. 80% of the lymphocytes were observed with the antibody against CD4, CD8 stained some lymphocytes surrounding solitary lipocytes in the adipose tissue. T-cell intracellular antigen-1 postive lymphocytes were present from the deep dermis to the subcutaneous tissue. There were no lymphocytes positive to CD30, 56, or latent membrane protein-1. Almost all large histiocytes were strongly positive for CD68 southern blot analysis showed clonality for the t-cell receptor beta-chain gene. No ln biopsy was performed may have been a case of concurrent cutaneous t-cell lymphoma (ctcl) but was diagnosed as patient unspecified

Remission Characteristics

One year after the CT scan, the right lesion disappeared but the left lesion was growing larger after the skin biopsy, the skin lesion gradually reduced and completely disappeared 6 moths later without therapy. Although the deep left inguinal lymph node swelling persisted, complete remission of the skin lesion is still observed

Treatment & Mechanisms

Proposed Remission Mechanisms

Surgical biopsy may have triggered immunological response

Clinical Treatment

None reported

Non-Clinical Treatment

None reported