Coexistence of Subcutaneous Panniculitis-Like T-Cell Lymphoma and Dermatomyositis in a 12-Year-Old Boy

Abstract

Subcutaneous panniculitis-like T-cell lymphoma (SPTL) is an extremely rare, indolent skin malignancy that can be difficult to distinguish from autoimmune disease-associated panniculitides. Here, we describe a 12-year-old boy who was diagnosed at age 7 years with dermatomyositis with classical manifestations, including poikiloderma, Gottron’s sign, and symmetric muscle weakness. Recently, the boy presented multiple subcutaneous nodules and fever. Histopathological examination and immunohistochemical staining revealed coexistence of SPTL. To our knowledge, this is the first case of dermatomyositis accompanied with SPTL. This case alert clinical physicians of the possibility of SPTL should be considered when a patient with dermatomyositis has new lesions presenting as nodules and unknown fever.

INTRODUCTION

Subcutaneous panniculitis-like T-cell lymphoma (SPTL) is a rare peripheral lymphoma that presents as a deep erythematous nodule or plaque, most often on the legs or the trunk. Histologically, SPTL is a cytotoxic neoplasm consisting of a subcutaneous infiltrate of pleomorphic T-lymphocytes that stain positive for T-cell markers and simulate a panniculitis, most often sparing the overlying dermis and epidermis¹,²,³. SPTL can be misdiagnosed as lupus erythematosus (LE) panniculitis. Willemze et al.⁴ reported that 19% of patients with SPTL had an associated autoimmune disease, including systemic lupus erythematosus (SLE), rheumatoid arthritis, Sjogren syndrome, type 1 diabetes mellitus, idiopathic thrombocytopenia, multiple sclerosis, Raynaud’s disease, and Kikuchi disease; SLE is the most common comorbidity for SPTL. To our knowledge, coexistence of SPTL with dermatomyositis (DM) has not been reported. Herein, we report a 12-year-old boy who was diagnosed with coexistent DM and SPTL.

CASE REPORT

A 12-year-old boy was referred to our department for diffuse erythematous plaques and fever. He was born healthy at full term from non-consanguineous parents. At 8 years of age, the child developed erythema on the skin of the right thigh and left chest, along with muscle weakness. The rash gradually spread to the whole body, showing eczematous lesions with pigmentation and mottling hypopigmentation. He had been previously diagnosed with DM, but was not treated systematically.

Physical examination showed diffuse erythematous plaques with telangiectasia (Fig. 1A, B). He presented with erythema and edema of the face. Mottling brown pigmentation and hypopigmentation was notable on the neck and groin area (Fig. 1C, D). He also exhibited typical Gottron’s papules near the metacarpophalangeal joint (Fig. 1E). Blood tests revealed elevated α-hydroxybutyrate dehydrogenase (250 U/L; normal, 72~182 U/L) and lactate dehydrogenase (662 U/ml; normal, 135~215 U/ml) levels. Other blood tests, including complete blood count and serum creatine kinase, were within normal limits. Magnetic resonance imaging (MRI) revealed many abnormal signal images of subcutaneous fat from the back of his waist to the side of the thigh (Fig. 1F). Histopathological examination of an erythema lesion on the patient’s abdomen (Fig. 1B) revealed a subtle interface dermatitis characterized by a sparse perivascular and periadnexal mononuclear cell infiltrate, rare individually necrotic keratinocytes, a focally thinned epidermis, and slight compact hyperkeratosis (Fig. 1G). Features also included basal vacuolization change (Fig. 1H). There was a local increase in reticular dermal mucin also well. Using the EULAR/ACR diagnostic criteria, we determine the diagnosis of juvenile dermatomyositis is appropriate.

Fig. 1. (A, B) Diffuse erythematous plaques with telangiectasia on the face and abdomen (arrow). (C, D) Notably mottling brown pigmentation and hypopigmentation on the neck and groin area. (E) Typical Gottron’s papules near the metacarpophalangeal joint. (F) Magnetic resonance imaging revealed many abnormal signal images of subcutaneous fat from the back of his waist to the side of the thigh. Histopathological findings showed (G) a subtle interface dermatitis characterized by a sparse perivascular and periadnexal mononuclear cell infiltrate, rare individually necrotic keratinocytes, a focally thinned epidermis, and slight compact hyperkeratosis (H&E, ×20). (H) Basal vacuolization change (H&E, ×100).

At the same time, we noticed that there were many indurated red plaques and nodules on the thighs (Fig. 2A, B). Intermittent fever had also developed 2 months prior to the physical examination. Another biopsy of the nodules on the patient’s left upper thigh (Fig. 2B) was performed for evaluation. Hematoxylin and eosin staining of skin biopsy specimen revealed dense lymphohistiocytic infiltration of the pannicular lobules with variably sized, cytologically atypical lymphoid cells and lymphocyte rimming of individual adipocytes in a wreathytesl manner (Fig. 2C, D). Immunohistochemical analysis showed the tumor cells were positive for CD3, CD8, and TIA-1, and negative for CD4, CD56, and EBV-encoded RNA (EBER); 60% of cells were positive for Ki67 (Fig. 2E~H). Monoclonal T-cell receptor (TCR) gene rearrangement was not found. We had also done the TCR betaF1 or TCR delta staining, so we rule out gamma/delta T-cell lymphoma.

Fig. 2. (A, B) Indurated red plaques and nodules on the thighs (arrow). Histopathological findings showed (C) dense lymphohistiocytic infiltration of the pannicular lobules with variably sized (H&E, ×20). (D) Atypical lymphoid cells and lymphocyte rimming of individual adipocytes in a wreathytesl manner (H&E, ×200). Immunohistochemical staining also showed (E) CD3+, (F) CD8+, (G) TIA-1, and (H) KI-67 were positive (×100).

Combined clinical manifestations, together with histopathological and immunohistochemical findings, suggested a diagnosis of SPTL. After consultation in hematology department, it is considered that there is no need for chemotherapy considering the patient’s current condition. The current treatment plan is: MTX:7.5 mg/week, prednisone:10 mg/qd. We have been closely following up and the patient’s condition has not progressed at present.

DISCUSSION

SPTL was initially described by Gonzalez as a rare, cytotoxic T-cell lymphoma primarily involving subcutaneous tissue that mimics panniculitis, predominantly affects the limbs, and is often complicated by a hemophagocytic syndrome. The incidence of SPTL is less than 1%⁴. Diagnosis of SPTL is challenging, especially in the early stages when the symptoms mimic other more common conditions such as benign panniculitis, eczema, dermatitis, cellulitis, and other skin and soft tissue infections.

It is known that systemic inflammatory rheumatic diseases may increase the risk for the development of malignancies, particularly lymphoproliferative disorders⁵. This increased risk applies to connective tissue diseases such as rheumatoid arthritis, SLE, scleroderma, and DM⁵. DM is a connective tissue disease of skin and muscle that may develop in adults in association with solid organ malignancies, including those of the head and neck, stomach, ovary, kidney, lung, and lymph nodes. Previous studies⁶ in SPTL patients reported overlapping cutaneous lesions showing serologic and pathological features of LE⁷. SPTL in previous studies was initially diagnosed as systemic vasculitis, nodular panniculitis, pyoderma gangrenosum, erythema nodosum, nodular panniculitis, DM, polymyositis, LEP, or Behcet’s disease. To date, coexistence of DM and SPTL has not been reported. In previous studies, three cases of SPTL were initially misdiagnosed as DM⁸,⁹,¹⁰. Chiu et al.⁸ reported an 83-year-old man who presented with symmetric, confluent violaceous erythema and edema on bilateral cheeks, forehead, neck, and upper chest, but absence of myopathic muscle weakness. Kaieda et al.⁹ reported a 58-year-old woman with a heliotrope rash who complained of myopathic muscle weakness; physical examination showed erythematous subcutaneous nodules on the upper and lower extremities. Yi et al.¹⁰ reported a 13-year-old boy who presented with erythematous papules, periorbital edema, and swollen cervical tissue, but absence of myopathic muscle weakness as well as normal laboratory and MRI examinations. These cases did not fulfill the diagnostic criteria for DM and none had Gottron’s sign, which is a typical clue for the diagnosis of DM. Our patient exhibited a typical Gottron’s sign at the metacarpophalangeal joint, coupled with muscle weakness, significantly elevated lactate dehydrogenase, and abnormal MRI results. Therefore, diagnosis of DM was confirmed. A comparation between our patient and three other reported cases is shown in Table 1.

Table 1. Clinical features, major laboratory, and histopathologic findings of three cases of SPTL were initially misdiagnosed as DM and our patient.

NO.	Sex/age (yr)	Location	Lesion manifestation	Muscle weakness	Fever, weight loss, and night sweat	Laboratory examinations			Magnetic resonance imaging	Histopathology	Immunohistochemistry	TCR gene rearrangement
						CK ↑	LDH ↑	α-HBDH ↑
1	F/58	Extremities	Erythematous subcutaneous nodules	+	+	–	–	–	Subcutaneous nodules showed high-signal intensity on magnetic resonance imaging	Subcutis was infiltrated with atypical lymphoid cells surrounded by adipocytes	CD3+/CD4–/CD8+/CD56–	-
2	M/83	Cheeks, forehead, neck and V area of upper chest	Erythema and edema	–	+	+	–	+	-	Lobular infiltrate of lymphocytes with rimming of adipocytes by atypical small to medium sized T lymphocytes and the presence of bean bag cells	CD3+/CD4–/CD8+/CD56–	-
3	M/13	Cervical	Papules and edema	–		+	–	–	-	-	CD3+/CD4–/CD8–/CD56+	TCRδ+
Our patient	M/12	Trunk and limbs, metacarpophalangeal joint area	Erythema with abnormal pigmentation, red nodules and Gottron sign	+	+	–	+	+	Multiple abnormal signal images of subcutaneous fat from the back of the waist to the side of the thigh	Infiltrates of atypical lymphocytes, rimming of individual adipocytes in a wreathytesl manner	CD3+/CD8+/CD4–/CD56–	-

SPTL: subcutaneous panniculitis-like T-cell lymphoma, DM: dermatomyositis, CK: creatine kinase, LDH: lactate dehydrogenase, α-HBDH: α-hydroxybutyrate dehydrogenase, F: female, M: male.

Fat lobule rimming can also can be observed in DM panniculitis. However, the histologic features of DM panniculitis includes multifocal hyalinization of the subcuticular fat and diffuse lobular infiltrates of mature lymphocytes without nuclear atypia. But multifocal hyalinization of the subcuticular fat was not observed in our patient’s histopathological examination.

In conclusion, we reported the first known coexistence of SPTL and DM in a 12-year-old boy. The possibility for SPTL should be considered when a patient with DM has new lesions presenting as nodules and unknown fever. Biopsy of the deep-seated lesions should be performed to establish early diagnosis and prompt treatment.