Positron emission tomography in subcutaneous panniculitis-like T-cell lymphoma

Relapsed subcutaneous panniculitis-like T cell lymphoma evaluated by FDG PET/CT: A clinical case report

RATIONALE

Subcutaneous panniculitis-like T cell lymphoma (SPTCL) is a rare primary cutaneous T cell lymphomas expressing α/β T cell receptors that preferentially involves subcutis, and few reports have investigated the diagnosis of suspicious relapsed SPTCL using F-fluoro-2-deoxy-D-glucose (F-FDG) positron emission tomography/computed tomography (PET/CT).

PATIENT CONCERNS

A 15-year-old woman complaining of a growing painless subcutaneous mass on perinaeum recurred 2 months ago, suggestive of suspicious relapsed SPTCL, underwent FDG PET/CT for diagnosis and treatment follow-up.

DIAGNOSIS

Based on the feature of FDG PET/CT images which revealed multiple increased FDG-avid subcutaneous adipose tissue lesions on the left upper arm, the left chest and perinaeum, involvement of bilateral inguinal lymph nodes, and the effective chemotherapy, she was diagnosed with relapsed SPTCL.

INTERVENTIONS AND OUTCOMES

Fortunately, the patient's skin lesions subsided gradually after 3 cycles of cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP) regimen. Besides, complete remission was observed on interim-FDG PET/CT after 3 cycles of CHOP treatment.

LESSONS

FDG PET/CT can clarify the diagnosis in suspicious relapsed SPTCL, avoiding performing skin biopsy again.

Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography evaluation of subcutaneous panniculitis-like T cell lymphoma and treatment response

Subcutaneous panniculitis-like T cell lymphoma (SPTCL) is a very rare variant of non-Hodgkin’s lymphoma. Currently, there is no standard imaging method for staging of SPTCL nor for assessment of treatment response. Here, we describe our use of fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for staging and monitoring of treatment response in 3 cases of SPTCL. Primary staging by PET/CT showed that all 3 patients had multiple foci in the subcutaneous fat tissue, with SUVmax from 10.5 to 14.6. Involvement of intra-abdominal fat with high SUVmax was identified in 2 of the patients. Use of the triple drug regimen of gemcitabine, cisplatin and methylprednisolone (commonly known as “GEM-P”) as first-line therapy or second-line therapy facilitated complete metabolic response for all 3 cases. FDG PET/CT provides valuable information for staging and monitoring of treatment response and can reveal occult involvement of the intra-abdominal visceral fat. High FDG uptake on pre-treatment PET can identify patients with aggressive disease and help in selection of first-line therapy.

Subcutaneous Panniculitis-Like T-Cell Lymphoma: A Rare Tumour

Subcutaneous Panniculitis like T cell Lymphoma (SPTCL) is an uncommon variant and poorly differentiated type of cutaneous T cell lymphoma. Here we describe the case of a 19-year-old female who presented with swelling of left half of the face with no regional lymphadenopathy and hepatosplenomegaly which was initially misdiagnosed as a benign cutaneous condition by various practitioners. Histopathological examination revealed diffuse infiltration of subcutaneous plane by small to medium sized atypical lymphocytes. Immunohistochemistry showed CD3, CD8 and βF-1 positivity; CD20, CD56, Epstein Barr Virus (EBV) and TCR-δ negativity. Clinical profile, histopathology and immunohistochemical analysis yielded a diagnosis of SPTCL. Thus cases with atypical and nonresolving dermatological lesions should raise a suspicion of SPTCL as diagnosis against other benign conditions.

Subcutaneous Panniculitis-like T Cell Lymphoma Mimicking Early-Onset Nodular Panniculitis

Patient: Male, 24

Final Diagnosis: Subcutaneous panniculitis-like T-cell lymphoma

Symptoms: Fever • skin nodules

Medication: —

Clinical Procedure: Skin biopsy • PET-CT

Specialty: Hematology

Positron emission tomography revealed diffuse involvement of the lower legs and occult extracutaneous lesions in subcutaneous panniculitis-like T-cell lymphoma

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a very rare type of cutaneous lymphoma that localizes primarily in the subcutaneous adipose tissue without palpable involvement of the lymph nodes. Most often, it presents as multiple, painless, subcutaneous nodules on the extremities and trunk. In this study, we describe an unusual case of SPTCL that mimicked phlegmonous inflammation; PET/CT revealed massive diffuse involvement of the lower legs, low-grade nodal active disease, and occult involvement of the intra-abdominal visceral fat. A repeat PET/CT study after CHOP chemotherapy revealed complete resolution of abnormal FDG uptake in the initially involved sites.

Usefulness of F-18 FDG PET/CT in subcutaneous panniculitis-like T cell lymphoma: disease extent and treatment response evaluation

BACKGROUND.: Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare form of cutaneous lymphomas, accounting for less than 1% of cases of non-Hodgkin's lymphoma. Fluorine-18 fluorodeoxyglucose (F-18 FDG) positron-emission tomography/computed tomography (PET/CT) findings of SPTCL before and after treatment were rarely reported. CASE REPORT.: We report a case of SPTCL in which F-18 FDG PET/CT showed increased FDG accumulations in numerous subcutaneous nodules without extracutaneous disease. Contrast-enhanced CT during F-18 FDG PET/CT showed multiple minimally enhancing nodules with an infiltrative pattern in the subcutaneous layer throughout the body. Follow-up F-18 FDG PET/CT after three cycles of CHOP chemotherapy showed a complete metabolic remission of the lesions. CONCLUSIONS.: F-18 FDG PET/CT is suggested to be useful in assessing the disease activity, extent and treatment response in SPTCL.

Radiological and clinical features of subcutaneous panniculitis-like T-cell lymphoma

OBJECTIVE

To retrospectively analyze computed tomography (CT) and clinical findings of patients with subcutaneous panniculitis-like T-cell lymphoma (SPTCL).

MATERIALS AND METHODS

The CT findings were retrospectively assessed in 8 patients (6 men, 2 women; age range, 23-60 years; mean age, 39.8 years) with pathologically proven SPTCL. The tumor location, number, distribution, size, and morphological characteristics on CT were evaluated, as were maximum standardized uptake values on positron emission tomography. We also evaluated patient symptoms, laboratory findings, immunophenotype, involvement of bone marrow, treatment, and outcomes.

RESULTS

All 8 patients had multiple (range, 4 to numerous) soft tissue lesions involving subcutaneous fat tissue of the chest, abdominal wall, back, and buttock. Lesions varied in size (range, 0.5-10 cm) and showed reticular (n = 1), nodular (n = 4), and diffuse infiltrative (n = 3) patterns. Three patients had lesions involving the entire thickness of fat tissue, 3 had partial lesions, and 2 had variable lesions. Skin thickening was mild in 4 patients, moderate in 2, and severe in 2; fascia thickening was mild in 3 patients, moderate in one, severe in one, and variable in 2. In 7 patients, lesions were accompanied by engorged supplying vessels. At onset, maximum standardized uptake values varied from 1.2 to 4.7, decreasing to 0.0 to 4.2. Five patients had αβ type and one had γδ type. Clinical outcome varied: two remain alive with disease, two had no disease, and one died.

CONCLUSIONS

The SPTCL is characterized by multiple, nodular, or diffuse soft tissue lesions involving subcutaneous fat tissue, accompanied by engorged vessels and skin and fascial thickening. Patients vary in presentation and in treatment outcomes.

An illustrative case of subcutaneous panniculitis-like T-cell lymphoma

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a very rare form of skin lymphoma that is localized primarily to the subcutaneous adipose tissue without palpable involvement of the lymph nodes. Diagnosis of SPTCL is a challenge, especially during its early phases when symptoms mimic other, more common conditions, such as benign panniculitis, eczema, dermatitis, psoriasis and cellulitis. Clinical and systemic features are nonspecific and can include fever, chills, and weight loss. Further complicating diagnosis is the high number of false negatives provided by biopsy. Here we present a case of SPTCL that illustrates the full course of the disease, from presentation and multiple misdiagnoses to correct disease recognition and successful treatment. A review of the challenges of diagnosis is provided with recommendations for more accurate and timely recognition of SPTCL.