Age: 50.0
Sex: F
Vaccine: TTOX
Symptoms: Flow cytometry, Haemoglobin normal, Histiocytosis, Lymphadenopathy, Lymphocyte morphology abnormal
Clinical narrative: Initial case was retrieved from the scientific literature on 08 June 2012. The following is verbatim from the report: "A 50-year-old woman was administered a routine adult immunization booster of 0.5 ml (5 Lf units) tetanus toxoid into her left deltoid muscle. Within 72 h she developed an enlarged 6-cm left supraclavicular lymph node. Her primary-care physician suggested observation. At 4 weeks after the injection, the lymph node remained enlarged, but smaller. At 7 weeks after toxoid injection, the node was still palpable, but further decreased to 2.5 cm. Owing to its persistence, the patient underwent an excisional biopsy. The initial pathology review reported a small lymph node focally infiltrated by sheets of small-to-medium sized atypical lymphocytes, with histiocytic cells scattered uniformly within the atypical lymphoid infiltrate, Flow cytometry analysis was interpreted as an atypical T-cell population co-expressing CD4 and CD8. The report described these findings as consistent with a T-cell lymphoproliferative disorder, specifically T-cell prolymphocytic leukemia/lymphoma (T-PLL). A PET/CT scan revealed no definite scintigraphic evidence of fluorodeoxyglucose avid malignancy. The patient referred herself to our center for discussion of treatment options. On out evaluation, she was asymptomatic, specifically without B symptoms Her examination revealed no adenopathy or hepatosplenomegaly. Her white blood cell count was 7.9 x 103/mm3, hemoglobin was 13.9 gm/dl and platelet count was 291 x 103/mm3. Comprehensive metabolic panel and lactate dehydrogenase were entirely normal. A review of the patient's lymph node sections revealed a partial loss of architecture with marked peracortical zone expansion. The cells in that zone were monotonous and small with slightly irregular nuclear membranes, but had no prominent nucleoli. Scattered among these lymphocytes were band histiocytes with foamy cytoplasm. The original dot plot of the flow cytometry was requested for review. On re-examination, we suspected that the CD8 expressed in T lymphocytes were somewhat brighter than normal and very dimly, probably nonspecifically, in the CD4 T cells. This gave the original analyst the erroneous impression of abnormal coexpression of CD4 and CD6 in the CD3+ T cells. We estimated the CD4:CD8 ratio to be approximately 10:1. We requested the blocks for immunohistochemistry. Indeed, we found that the expanded CD3+ T cells expressed CD4 only, with very few expressing CD8, and no double expression of CD4 and CD8. In addition, we found no less of CD5 expression and only some CD7 loss. TdT and CD34 stains were negative. Our diagnosis was a 'pseudolymphomatous' florid proliferation of CD4 T cells in response to the tetanus toxoid immune stimulation, not lymphoma. Bone marrow biopsy revealed normal marrow cellularity (70-80%) with trilineage hematopoietic maturation and no abnormal cells. Flow cytometry of blood and bone marrow revealed no clonal B-cell or T-cell abnormalities. The CD4:CD8 ratio in the patient's blood was 3:1 and in the marrow 2.5:1. No double-expressing T cells were identified." Documents held by sender: None.