Report of Eleven Patients of Subcutaneous Panniculitis-Like T-Cell Lymphoma: Clinicopathologic Features, 18F-FDG PET/CT Findings and Outcome

Clinicopathological Characteristics and Outcome of Cytophagic Histiocytic Panniculitis: A Single-Center, Retrospective Study

Background

Cytophagic histiocytic panniculitis (CHP) is a rare panniculitis associated with systemic features characterized by the infiltration of subcutaneous adipose tissue by benign-appearing T lymphocytes and phagocytic histiocytes, mimicking hemophagocytic lymphohistiocytosis (HLH) and subcutaneous panniculitis-like T-cell lymphoma (SPTCL).

Purpose

To establish the clinicopathological features and response to treatment of CHP and evaluate the prognosis of patients and guide therapy based on the current state of knowledge.

Material and Methods

Clinical, laboratory, histopathological, and outcome data of 12 patients with CHP were retrospectively collected between 2009 and 2022.

Results

All the patients presented with plaques or nodules, mostly located in the lower extremities (11/12). Fewer cases involved systemic symptoms (9/12) and laboratory abnormalities (6/12), and none were positive for serum Epstein-Barr virus (EBV)-DNA. Histopathological examination revealed mixed septal and lobular inflammatory infiltration of histiocytes and lymphocytes. Large or atypical lymphocytes were rarely present (2/12). In some patients, varying proportions of plasma cells, neutrophils, and eosinophils were observed. The extent of histocytophagy was mild (9/12), moderate (2/12), and severe (1/12). HLH was not observed in any of our cases, none of which were fatal.

Conclusion

The uniqueness of our study lies in the presence of neutrophil-rich dermal and subcutaneous infiltrates, associated with connective tissue disorders (CTD) and streptococcal infections. Our study reveals that EBV-negative CHP tends to a better prognosis than previously research, filling the gap in the much-needed details of CHP in the Chinese population. Moreover, CHP may present as a reactive process in combined primary diseases; further studies are required to validate these findings.

Subcutaneous panniculitis-like T-cell lymphoma: fever and facial swelling with hemophagocytic syndrome

We report a case of subcutaneous panniculitis-like T-cell lymphoma (SPTCL) in a young man presenting with fever and facial swelling. He had pancytopenia and hemophagocytic syndrome (HPS) on evaluation. The histopathological examination of skin punch biopsy from the face and chest wall showed SPTCL. Given the associated HPS, he was started on steroid and multidrug chemotherapy following which he had symptomatic improvement.

Subcutaneous panniculitis-like T-cell lymphoma: Morphological, immunophenotypical and clonality assessment in six cats

BACKGROUND

Primary cutaneous lymphoma represents 0.2%-3% of all feline lymphomas, with nonepitheliotropic lymphomas being the most common. In humans and dogs, subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a primary nonepitheliotropic lymphoma with a T-cell phenotype developing in the subcutis and often mimicking inflammation.

OBJECTIVE

The aim of this report is to describe pathological, phenotypical and clonal features of SPTCL in cats.

ANIMALS

Six cats with SPTCL were included in this study.

MATERIALS AND METHODS

Skin biopsies were formalin-fixed, routinely processed and stained. Histological and immunohistochemical investigation for anti-CD18, CD204, CD79a, CD20, CD3, FeLVp27and FeLVgp70 and clonality assessment were performed.

RESULTS

Four male and two female domestic shorthair cats, mean age 11.2 years, developed SPTCL in the abdominal (three), inguinal (two) and thoracic (one) regions. Variably pleomorphic neoplastic lymphoid cells were present in the panniculus in percentages, expanding the septa (six of six) and extending into fat lobules in one of six cats. Tumours were associated with elevated numbers of neutrophils (five of six), lesser macrophages (six of six) and variable necrosis (six of six). Neoplastic cells expressed CD3+ (six of six), with clonal T-cell receptor rearrangement detected in five of six cats.

CONCLUSIONS AND CLINICAL RELEVANCE

This is the first description of SPTCL in cats. Lesions can be confused with panniculitis, leading to delay in diagnosis and therapy. Awareness of this neoplastic disease is relevant to avoid misdiagnoses and to gain greater knowledge about the disease in cats.

An unusual presentation of subcutaneous panniculitis-like T-cell lymphoma: Extensive necrosis and hemophagocytic lymphohistiocytosis: A case report

Key Clinical message

Subcutaneous panniculitis-like T-cell lymphoma, a primary cutaneous lymphoma, which is described as following a slow course, could claim life. The occurrence of facial and breast nodules, the association with hemophagocytic lymphohistiocytosis, and the extent of necrosis and ulceration are signs of its aggressive nature needing early diagnosis and prompt treatment.

Abstract

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare skin disease that accounts for <1% of all peripheral T-cell lymphomas. It is described as following a slow and gradual process. However, it can be associated with a variety of clinical symptoms ranging from mild to severe. Hemophagocytic lymphohistiocytosis (HLH), a rare and potentially fatal hematologic factor that complicates SPTCL in 20% of cases, is an important prognostic factor. We report here an aggressive case of disseminated SPTCL with HLH involving a young woman who presented with extensive necrosis and ulceration at diagnosis. The report highlights the aggressive course of the disease, the occurrence of facial and breast nodules, the association with HLH, and the extent of necrosis and ulceration. The report highlights the poor prognosis despite polychemotherapy regimen use.

The role of 18F-FDG PET/CT in primary cutaneous lymphoma: an educational review

INTRODUCTION

Primary cutaneous lymphoma (PCL) is a cutaneous non-Hodgkin's lymphoma that originates in the skin and lacks extracutaneous spread upon initial diagnosis. The clinical management of secondary cutaneous lymphomas is different from that of PCLs, and earlier detection is associated with better prognosis. Accurate staging is necessary to determine the extent of disease and to choose the appropriate treatment. The aim of this review is to investigate the current and potential roles of ¹⁸F- fluorodeoxyglucose positron emission tomography-computed tomography (¹⁸F-FDG PET/CT) in the diagnosis, staging, and monitoring of PCLs.

METHODS

A focused review of the scientific literature was performed using inclusion criteria to filter results pertaining to human clinical studies performed between 2015 and 2021 that analyzed cutaneous PCL lesions on ¹⁸F PET/CT imaging.

RESULTS & CONCLUSION

A review of 9 clinical studies published after 2015 concluded that ¹⁸F-FDG PET/CT is highly sensitive and specific for aggressive PCLs and proved valuable for identifying extracutaneous disease. These studies found ¹⁸F-FDG PET/CT highly useful for guiding lymph node biopsy and that imaging results influenced therapeutic decision in many cases. These studies also predominantly concluded that ¹⁸F-FDG PET/CT is more sensitive than computed tomography (CT) alone for detection of subcutaneous PCL lesions. Routine revision of nonattenuation-corrected (NAC) PET images may improve the sensitivity of ¹⁸F-FDG PET/CT for detection of indolent cutaneous lesions and may expand the potential uses of ¹⁸F-FDG PET/CT in the clinic. Furthermore, calculating a global disease score from ¹⁸F-FDG PET/CT at every follow-up visit may simplify assessment of disease progression in the early clinical stages, as well as predict the prognosis of disease in patients with PCL.

Inverted FDG Uptake Pattern in Subcutaneous Panniculitis-Like T-Cell Lymphoma

ABSTRACT

A 47-year-old woman presented with a 2-month history of subcutaneous nodules, erythema, and fever. 18F-FDG PET images demonstrated inverted FDG uptake pattern corresponding to the subcutaneous lesion against lymph nodes. The specimen of the inguinal lesion showed massive infiltration of small lymphocytes in the adipose tissue with rimming adipocytes, whereas very few tumor cells infiltrated the lymph nodes. Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) was diagnosed. SPTCL normally shows quite interesting distribution of tumor cells, that is, lymph node involvement is usually absent. Therefore, this case highlighted the importance of the inverted accumulation pattern on FDG PET to suspect SPTCL.

18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Scan Findings in a Rare Case of Subcutaneous Panniculitis-Like T-Cell Lymphoma

Skin lymphomas are less common and subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a fairly rare subtype of primary cutaneous lymphoma. Skin lymphomas involve subcutaneous adipose tissues with no involvement of lymph nodes. Diagnosis of these cases is generally a challenge to clinicians. These cases present with fever, weight loss, and local discomfort in the region of involvement of subcutaneous tissues and sometime with skin eczema and rashes. Positron emission tomography/computed tomography (PET/CT) scan can guide in determining the extent of involvement being whole-body imaging and can guide the site of biopsy and can help to prevent misdiagnosis. It also helps in correct and early diagnosis and successful treatment. We report a case of a young adult who presented with pyrexia of unknown origin in which PET/CT scan revealed mildly fluorodeoxyglucose-avid diffuse subcutaneous panniculitis involving the whole body, trunk, and extremities. Biopsy was taken from the most appropriate site according to the PET/CT scan report and reported as SPTCL.

CD20-positive subcutaneous panniculitis-like T-cell lymphoma presenting as polycranial neuropathy: A CARE-compliant case report and literature review

BACKGROUND

Subcutaneous panniculitis-like T-cell lymphoma(SPTCL) is a very rare cytotoxic T-cell skin lymphoma involving subcutaneous tissue, and mainly affects young females. T-cell phenotype is characterized by CD3+, CD8+, and CD4-. SPTCT with polycranial neuropathy has rarely been described. SPTCL is believed to show an indolent clinical course unless patients develop haemophagocytic syndrome or sudden respiratory failure. Its treatment has not been established yet.

CASE PRESENTATION

We report a case of intractable SPTCT in a 66-year-old woman with multiple cranial nerve palsies and diabetes. She showed involvement of the bilateral facial nerve, left trigeminal nerve, left auditory nerve, and right oculomotor nerve. The single inconspicuous skin lesion in the trunk presented with an erythematous nodule with a diameter of <5 cm and a slightly pink infiltrated plaque. Electromyography revealed bilateral damage to the facial nerve. Differential immunohistochemical characteristics were observed. Immunohistochemistry demonstrated diffuse CD20 positivity. Cerebral spinal fluid analysis revealed elevated protein levels of 0.92 (0.15-0.45) g/L. Her condition regressed severely over time. She was treated with chemotherapy but died 10 months later, the probable cause of death was lung involvement.

CONCLUSION

The patient's involvement with the central nervous system may be associated with positivity for CD20. Molecular biomarkers may act as therapeutic targets for SPTCL.

F-18-FDG PET/CT findings of paraneoplastic dermatoses

Paraneoplastic dermatoses (PD) are defined as nonspecific skin disorders which are associated with internal neoplasms, but without direct association to primary tumors or metastases. Recognition of PD and the following surveillance may lead to the diagnosis of internal malignant neoplasms including early stage ones. Accurate imaging examinations in the following searching is essential in identifying the underlying neoplasms. Since whole-body 18-fluoro-2-deoxyglucose (F-18-FDG)-positron emission (PET)/computed tomography (CT) has been widely used in early diagnosis, staging of various malignant tumors, it may play a role for detection of underlying or occult malignant neoplasms in patients with PD. However, to date, only a few reports of FDG PET/CT findings of the associated neoplasms in PD patients have been cited in the literature. The present paper shows the cases of FDG-avid associated neoplasms in patients with PD in our 10-year experience in our institute, and reviews the well-known and/or relatively common PD and their associated neoplasms, and the previously reported cases of FDG-avid associated neoplasms in these patients.