To the editor: We report a 23-year-old Chinese man, who presented with a 2-month history of recurrent eruptions of asymptomatic, red, necrotic papules on his face and extremities. The skin lesions would regress spontaneously within several days, leaving atrophic scars. He had no systemic symptoms. A physical examination revealed many papules and nodules on his trunk and extremities (Figure 1A). Some papules had a necrotic center covered by black crusts. No lymphadenopathy was found. The results of peripheral blood counts, biochemical tests and urinalysis were within normal limits. The findings of chest CT and abdominal ultrasonography were unremarkable. Histological evaluation of the biopsy specimens from the abdomen and thigh showed lymphoid infiltrations in the dermis and superficial subcutaneous layer. The infiltrates in the superficial dermis were denser, composed of medium-to-large, atypical lymphoid cells with round or slightly irregular nuclei and showed pronounced epidermotropism, with scattered necrotic keratinocytes (Figure 1B). The deep dermis was infiltrated with medium lymphocytes, mainly around the vessels and appendages. A partial thickness of collagen bundles in a wedge-shaped pattern and fibrinoid degeneration of the vessel walls were observed (Figure 1C). In the subcutaneous layer, a few small lymphocytes and foamy cells infiltrated the lobules. Immunohistochemical staining revealed that the atypical lymphocytes expressed CD3ε, CD8, CD30, TIA-1 and GrB, but not CD3, CD4, CD20, CD56 and CD79a. TCR gene rearrangement was detected on polymerase chain reaction assay (Figure 1D), whereas Epstein-Barr (EB) virus (EBER-1/2) was not detected on in situ hybridization. The patient was started on treatment with oral compound glycyrrhizin and topical corticosteroids for 6 months. His skin lesions have significantly reduced, and he has had no other symptoms during the past 8 months.
Lymphomatoid papulosis (LyP) is a rare, self-healing, recurrent, cutaneous T-cell lymphoma that appears histologically malignant but is clinically benign. LyP is usually histologically classified into types A, B and C. Types A and C are characterized by a wedge-shaped or diffuse infiltration, with large atypical inflammatory cells distributed in different proportions. Type B involves small-to-medium lymphocytes with cerebriform nuclei and a perivascular or band-like infiltration with epidermotropism. All three subtypes of LyP share the same indolent clinical behavior, and the 5-year survival rate is 100%.
Our patient had a typical clinical course of LyP, with some lesions resolving spontaneously over a few weeks; histological examination revealed a primary cutaneous aggressive epidermotropic CD8+ cytotoxic T-cell lymphoma. Saggini et al1 reported nine similar cases in 2010 and proposed the term LyP type D to describe this special entity. Since then, only one additional case has been reported.2 Type D is a newly described variant of LyP that has been recognized in recent years and has not yet been included in the latest World Health Organization classification.3 Besides, the thickness of collagen bundles in a wedge-shaped pattern in LyP type D was observed in this case. it has not been mentioned in previous studies.
This variant of LyP is frequently misdiagnosed as primary cutaneous aggressive epidermotropic CD8+ cytotoxic T-cell lymphoma. Differential diagnosis of these two lymphomas is extremely important because of their totally different biological behavior and treatment strategy. Mucosal involvement, tendency to develop ulcers and rapid progression with extracutaneous dissemination, such as to the lung, testis and central nervous system,4 should suggest the diagnosis of primary cutaneous aggressive epidermotropic CD8+ cytotoxic T-cell lymphoma. This lymphoma, unlike LyP, has a very poor prognosis; the median survival is only 22.5-33 months.5
1. Saggini A, Gulia A, Argenyi Z, Fink-Puches R, Lissia A, Magaña M, et al. A variant of lymphomatoid papulosis simulating primary cutaneous aggressive epidermotropic CD8+ cytotoxic T-cell lymphoma. Description of 9 cases. Am J Surg Pathol 2010; 34: 1168-1175.
2. Cardoso J, Duhra P, Thway Y, Calonje E. Lymphomatoid papulosis type D: A newly described variant easily confused with cutaneous aggressive CD8-positive cytotoxic T-cell lymphoma. Am J Dermatopathol 2012; 34: 762-765.
3. Swerdlow SH, Campo E, Harris NL, Jaffe ES, Pileri SA, Stein H, et al. WHO classification of tumours of hematopoietic and lymphoid tissues. IARC: Lyon; 2008.
4. Introcaso CE, Kim EJ, Gardner J, Junkins-Hopkins JM, Vittorio CC, Rook AH. CD8+ epidermotropic cytotoxic T-cell lymphoma with peripheral blood and central nervous system involvement. Arch Dermatol 2008; 144: 1027-1029.
5. Gormley RH, Hess SD, Anand D, Junkins-Hopkins J, Rook A, Kim EJ. Primary cutaneous aggressive epidermotropic CD8+ T-cell lymphoma. J Am Acad Dermatol 2010; 62: 300-307.