Lupus Profundus Mimicking Panniculitis
T-cell Lymphoma
Victor G. Prieto
UT-MD Anderson Cancer Center
Houston TX
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Clinical history:
A 20-year-old woman presented with a several month
history of painful nodules on the proximal arms and legs. She had been diagnosed as consistent with
subcutaneous T-cell lymphoma in an outside laboratory. After further clinical examination, the patient
had a previous history of lupus erythematosus with very high ANA.
Microscopic Features:
Sections show skin to the subcutaneous tissue. The
epidermis is essentially unremarkable. There is a cellular infiltrate characterized by small and large
lymphocytes, plasma cells, and rare eosinophils, involving both the dermis and subcutaneous tissue. In
the adipose tissue some of the lymphocytes are arranged around fat vacuoles ("rimming").
An immunohistochemical study in paraffin sections shows expression of CD20 by less than 10% of
the lymphocytes. CD3 labels more than 70% of the cells including those infiltrating the subcutaneous
tissue. CD4 is expressed by the majority of the cells in the infiltrate, both in the subcutaneous tissue
and in the septa. CD8 is expressed by approximately 40% of the cells in the infiltrate, some of them
surrounding fat cells. Only rare cells express CD56. Approximately 30% of the cells in the infiltrate
express granzyme B or TIA1, including some of the lymphocytes that surround the adipocytes. There is no
expression of EB virus antigens (LMP, EBER). PCR analysis fails to reveal a re-arrangement of the T-cell
receptor.
Diagnosis:
Lupus Profundus Mimicking Panniculitis
T-cell Lymphoma
Differential diagnosis:
Lupus panniculitis
Subcutaneous T-cell lymphoma
NK lymphoma
Discussion:
The main differential diagnosis is lupus panniculitis and
lymphoma. The histologic / immunohistochemical features (dense lymphocytic infiltrate involving the
adipose tissue with clusters of CD8 cells) suggest subcutaneous T-cell lymphoma. However, the young age,
high ANAs, and lack of re-arrangement of the T-cell receptor support a diagnosis of lupus panniculitis.
Biopsies from lupus patients in which there is involvement of the subcutaneous tissue usually
reveal a lobular panniculitis. In addition, there usually are a superficial and deep dermal lymphocytic
infiltrate with scattered plasma cells and different amounts of dermal mucin, occasionally with interface
dermatitis. Around 50% of the cases have a typical histologic picture consisting of germinal centers and
areas of fat necrosis. The immunohistochemical analysis confirms a predominance of T cells with a
mixture of CD4 and CD8 cells. The polymerase chain reaction analysis of the T-cell receptor (TCR)-gamma
gene is routinely negative.
Subcutaneous T-cell lymphoma commonly presents in middle-aged women, on the extremities,
characterized by a usually dense lymphocytic infiltrate, both in the dermis and subcutaneous tissue. The
infiltrate is composed by small and large lymphocytes as well as macrophages, which typically show
emperipolesis (phagocytosis of inflammatory cells and red blood cells). The lymphocytes are usually CD8
or NK cells (thus expressing CD56, TIA1, etc). As discussed above, although the observation of a rimming
of CD8 lymphocytes around fat vacuoles is suggestive of subcutaneous T-cell lymphoma, this finding can be
seen in other hematolymphoid processes including B and T-cell lymphomas as well as reactive lymphoid
infiltrates. The survival is poor, with a median of around 15 months after diagnosis.
The following factors are associated with better prognosis: age younger than 40 years, absence
of ulcer, absence of invasion of superficial dermis, CD8 expression while lacking CD56 or CD95
expression, gamma/delta subtype, and normal white blood cell counts and serum LDH. Furthermore, some
authors have proposed the term atypical lobular panniculitis for those cases
in young patients, with dense lymphocytic infiltrate of the subcutaneous tissue and also occasionally
having rearrangement of the TCR but with benign behavior. However, further analysis is necessary to
determine if these lesions constitute a separate group.
References:
Massone C, Kodama K, Salmhofer W, Abe R, Shimizu H, Parodi A, Kerl H, Cerroni L. Lupus
erythematosus panniculitis (lupus profundus): clinical, histopathological, and molecular analysis of
nine cases. J Cutan Pathol 2005, 32:396-404
Magro CM, Crowson NA, Byrd JC, Soleymani DA, Shendrik I. Atypical lymphocytic lobular
panniculitis. J Cutan Pathol 2004, 31:300-306
Takeshita M, Imayama S, Oshiro Y, et al. Clinicopathologic analysis of 22 cases of
subcutaneous panniculitis-like CD56- or CD56+ lymphoma and review of 44 other reported cases. Am J Clin
Pathol 2004, 121:408-416
Lozzi GP, Massone C, Citarella L, Kerl H, Cerroni L. Rimming of adipocytes by
neoplastic lymphocytes: a histopathologic feature not restricted to subcutaneous T-cell lymphoma. Am J
Dermatopathol 2006, 28:9-12
Ghobrial IM, Weenig RH, Pittlekow MR, Qu G, Kurtin PJ, Ristow K, Ansell SM. Clinical
outcome of patients with subcutaneous panniculitis-like T-cell lymphoma. Leuk Lymphoma 2005, 46:703-708
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