Skin infiltration of nodal peripheral t-cell lymphoma-not otherwise specified identified by skin biopsy of faint eruptions.

Sir,

An unusual skin symptom might be the first sign of an internal malignancy.[1] In the current WHO Classification, nodal peripheral T-cell lymphoma-not otherwise specified (PTCL-NOS) corresponds to a heterogeneous group of nodal and extranodal mature T-cell lymphomas that do not fit with any defined entities derived from mature T lymphocytes.[2] Here we report a case of skin infiltration of nodal PTCL-NOS identified by skin biopsy of faint eruptions.

A 58-year-old Japanese woman was referred to our department from the Department of Hematology in our hospital for diagnosis of a non-infiltrated erythema of 6 mm, an infiltrated erythema of 5 mm, and a small pink infiltrated papule of 3 mm in diameter that had been present on her right upper arm for seven weeks. [Figure 1] She had no subjective symptoms, but in the same period she had been diagnosed with nodal PTCL-NOS based on histologic findings in an excisional biopsy from a right cervical lymph node.

Figure 1

Faint eruptions on the right upper arm. •, a non-infiltrated erythema of 6 mm in diameter; ••, an infiltrated erythema of 5 mm in diameter; •••, a small pink infiltrated papule of 3 mm in diameter

At her first visit to our department, she appeared exhausted due to malaise associated with high fever (>38°C). Laboratory data including tests for liver and kidney function were within normal limits. Her white blood cell count was slightly elevated (9,000 × 103/μL), and red blood cell (3.38 × 106/μL) and platelet (42 × 103/μL) counts were decreased. The serum soluble interleukin-2 receptor level was elevated (7821 U/ml). Abnormal peripheral blood lymphocytes were not detected and she was negative for serum anti-human T-lymphotropic virus type-I antibody. Computed chest tomography and positron emission computed tomography showed splenomegaly and swollen lymph nodes in the neck, mediastinum, supraclavicular fossa, axilla, para-aorta, and inguinal region. T-cell receptor beta chain gene rearrangement was also detected.

Skin-punch biopsies (4 mm) from the two erythemas and an excisional biopsy from the papule were performed. Histopathologically the two erythemas showed mild and dense infiltration of hematoxylin-stained cells in the superficial and middle dermis, respectively [Figure 2a and b]. The papule showed deep nodular infiltration of hematoxylin-stained cells in the middle to deep dermis [Figure 2c]. At higher magnification, most hematoxylin-stained cells in the three specimens were found to be medium-sized monomorphic atypical lymphoid cells with prominent nucleoli, [Figure 2d] as seen in the right cervical lymph node. [Figure 2e] Immunohistochemically, these cells were positive for CD3, CD4, CD5 and CD8, and negative for CD10, CD21, CD34 and S100. Based on these findings, a diagnosis of skin infiltration of nodal PTCL-NOS was made. Ann Arbor stage IV B disease was diagnosed based on the presence of fever, imaging findings, and skin infiltration. After six courses of CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisolone) therapy, she underwent autologous stem cell transplantation. Subsequently, splenomegaly has been stable and lymphadenopathy has disappeared.

Figure 2

Hematoxylin-eosin-stained sections of specimens from the non-infiltrated erythema (a), infiltrated erythema (b), and infiltrated papule (c) on the right upper arm, (a) Histopathology of the non-infiltrated erythema showed a mild infiltrate of hematoxylin-stained cells in the superficial and middle dermis (H and E, ×40), (b) Histopathology of the infiltrated erythema showed a dense infiltrate of hematoxylin-stained cells in the superficial and middle dermis (H and E, ×40), (c) Histopathology of the infiltrated papule showed a deep nodular infiltrate of hematoxylin-stained cells in the middle to deep dermis (H and E, ×20), (d) Hematoxylin-stained cells were mainly medium-sized monomorphic atypical lymphoid cells with prominent nucleoli, as seen in the right cervical lymph node, (e) (d and e, H and E, ×400)

Nodal PTCL-NOS shows paracortical or diffuse infiltration with effacement of the normal architecture. In the skin, the tumor infiltrates the dermis and subcutis, and often forms nodules, sometimes with central ulceration.[2] While our case only showed three faint eruptions on the right upper arm. Different manners of dermal infiltration of atypical lymphocytes may reflect gross findings of eruptions. Thus, in our case, skin infiltration of nodal PTCL-NOS may have first occurred in the superficial dermis via the lymphatic vessels, and then in the deep layer of the skin, and manifested clinically as a non-infiltrated erythema, infiltrated erythema, and small pink infiltrated papule, respectively.

To the best of our knowledge, there have been no previous reports on skin infiltration of nodal PTCL-NOS identified by skin biopsy of faint eruptions. Lymphoma requires prompt diagnosis and accurate monitoring of progression since it is life-threatening disease. Therefore, histopathological examination of an unusual skin symptom is important, in addition to full-body examination and palpation, especially in patients with a history of internal malignancy.