|LETTER TO EDITOR
|Year : 2011 | Volume
| Issue : 1 | Page : 113-115
Angiocentric NK/T-cell lymphoma mimicking pyoderma gangrenosum
PO Emanuel, SE Mercer
Division of Dermatopathology, Mount Sinai Medical Center, New York, NY 10128, USA
|Date of Web Publication||10-Feb-2011|
P O Emanuel
Division of Dermatopathology, Mount Sinai Medical Center, New York, NY 10128
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Emanuel P O, Mercer S E. Angiocentric NK/T-cell lymphoma mimicking pyoderma gangrenosum. Indian J Cancer 2011;48:113-5
A 57-year old male presented to our medical center with progressive diplopia, a 30-pound weight loss over a 2−3-month period, and 5 months of progressive painless nasal obstruction with intermittent epstaxis. He had noticed a skin lesion developed in his left leg over the course of the last month. It had started as a small raised papule and had expanded quickly and become progressively painful. On examination, he also had a large ulcerated lesion (6.8 cm) on his left leg with a violaceous border that overhung the ulcer bed, which resembled pyoderma gangrenosum (PG). A skin biopsy was performed [Figure 1]a, b.
|Figure 1: (a) Examination of the left leg showed a large ulcerated lesion (6.8 cm) with a violaceous border that overhung the ulcer bed. (b) Histopathologic examination exhibited an angiocentric population of medium to large atypical lymphocytes with irregular nuclear folding with a granular appearance (Hematoxylin−Eosin stain, ×400).|
Click here to view
Skin biopsy exhibited ulceration with exuberant secondary changes. The vessel walls were infiltrated by inflammatory cells, which at first blush resembled a vasculitis or inflammatory changes commonly seen adjacent to ulceration. On close inspection, a dermal and subcutaneous infiltration of medium to large atypical lymphocytes with irregular nuclear folding was appreciated. Immunohistochemical studies revealed cell surface positivity for CD3e, and were also positive for CD43 and CD56. In situ hybridization for Epstein−Barr virus was positive, as were T-cell gene rearrangement studies.
The diagnosis of cutaneous extranodal, NK/T-cell lymphoma (ENKTCL) was made.
A subsequent biopsy was performed on the nasal lesion to reveal identical histolopathology. Laboratory data showed a mild leucopenia (WBC count: 2.76 × 10 9 l−1 ) with a normal differential count, a hemoglobin level of 12.3 g dl−1 and platelet count of 237 × 10 9 l−1 . The serum LDH was 449 IU l−1 and alkaline phosphatase 96 IU l−1 .
Pyoderma gangrenosum is a diagnosis of exclusion. Diagnosis of PG in patients who have other causes for severe cutaneous ulceration can result in substantial complications. In a study of 240 patients with a presumed diagnosis of PG over a 25-year period, five cases were said to represent angiocentric lymphoma. 
Extranodal NK/T-cell lymphoma represents a group of distinct extranodal neoplasms that are common in Asia and Latin America. It is characteristically located in the midline of the head and neck region. ENKTCL of the ''nasal-type'' shows the same histopathologic features as the sinonasal/nasal subtype, but arises from extranasal sites, and skin is the most common extranasal site.  The clinical appearance of PG as shown in the case herein has been rarely reported. ,
The histopathology of ENKTCL exhibits an angiocentric population of atypical lymphocytes, which stain positive immunohistochemically with CD56, CD3 (cell surface), CD45Ro, CD2, CD43. There has been considerable confusion in the literature in distinguishing NK cell lymphoma from NK-like T-cell lymphoma. Both can demonstrate positive cytoplasmic staining with CD3. The differentiating factor is that NK-like T-cell lymphomas demonstrate surface staining with CD3e and show clonality of T cells. The etiological role of EBV was first reported in 1990 and has since been regularly reported. It has also been stated that Epstein−Barr virus positivity is more common in true NK cell lymphomas than NK-like T-cell lymphomas. The prognosis is dismal. Early stage disease may respond to radiotherapy alone; however, late stage disease generally does not respond well to any available therapies. Overall, patients with ENKTCL have a cumulative probability of survival at 5 years ranging from 37.9% to 45.3%.  This patient died 8 weeks following the initial presentation despite chemotherapy with IMEP (ifosfamide, methotrexate, etoposide, and prednisone). Autopsy revealed multiple organ involvement with lymphoma.
| » References|| |
|1.||Weenig RH, Davis MD, Dahl PR, Su WP. Skin ulcers misdiagnosed as pyoderma gangrenosum. N Engl J Med 2002;347:1412-8. |
|2.||Helm KF, Su WP, Muller SA, Kurtin PJ. Malignant lymphoma and leukemia with prominent ulceration: Clinicopathologic correlation of 33 cases. J Am Acad Dermatol 1992;27:553-9. |
|3.||Aozasa K, Takakuwa T, Hongyo T, Yang WI. Nasal NK/T-cell lymphoma: Epidemiology and pathogenesis. Int J Hematol 2008;87:110-7. |
|4.||Kim WS, Park YH, Lee SH, Ryoo BY, Yang SH, Lee SS, et al. Extranodal nasal type NK/T-cell lymphoma: Elucidating clinical prognostic factors for risk-based stratification of therapy. Eur J Cancer 2005;41:1402-8. |