Acquired idiopathic lipoatrophic panniculitis in a 12‐month‐old infant

Lipoatrophic panniculitis is a rare condition affecting mainly children, often associated with connective tissue disease. We report a healthy 12‐month‐old girl with no clinical or laboratory features of connective tissue disease who presented with the progressive appearance of annular atrophic plaques beginning at the left arm. A histopathological analysis revealed lobular panniculitis, with fat necrosis and an associated inflammatory infiltrate supporting the diagnosis of lipoatrophic panniculitis. Lipoatrophic panniculitis should be considered in infants and young children with clinical features of panniculitis and fat atrophy even without clinical or serologic evidence of connective tissue disease.     

Postirradiation pseudosclerodermatous panniculitis

Pseudosclerodermatous panniculitis is an unusual variant of panniculitis that results as a complication of megavoltage radiotherapy. Four women developed this unusual entity on the anterior chest and abdominal skin after receiving megavoltage therapy for either breast carcinoma or painful bone metastases from breast carcinoma. Histopathologically, the epidermis and dermis of the involved area showed little or no evidence of radiodermatitis. The main findings were confined to the subcutaneous tissue and consisted of thickened, sclerotic septa composed of both thick and thin collagen bundles, and a lobular panniculitis characterized by lipophagic granulomas and scattered lymphocytes and plasma cells. Additionally, one of the cases showed markedly dilated vascular spaces with the appearance of lymphatics in the upper part of the dermis. Pseudosclerodermatous panniculitis after irradiation is an unusual cutaneous complication of megavoltage radiotherapy that should be distinguished from subcutaneous metastatic disease, cellulitis, or connective tissue diseases involving the subcutaneous fat. The differential diagnosis can be established on the basis of the characteristic histopathologic features of postirradiation pseudosclerodermatous panniculitis.     

Panniculitis–an unusual cutaneous manifestation of systemic sclerosis

Systemic sclerosis (SSc) is an autoimmune systemic disease characterized by small vessel involvement that leads to tissue ischemia and fibroblast stimulation resulting in accumulation of collagen (fibrosis) in the skin and internal organs. Lipomembranous panniculitis is a peculiar type of fat necrosis and has been reported with clinical conditions, commonly with peripheral vascular diseases. We describe a case of a 43‐year‐old woman with SSc manifestations, who presented with black scaly skin plaques, associated with thickening of the subcutaneous fat tissue, on the lateral surface of her thighs, her calves, gluteal area and lower abdomen. Biopsy revealed lipomembranous panniculitis. Lipomembranous changes have been seen in connective tissue disorders such as lupus profundus, morphea, systemic sclerosis and panniculitis associated with dermatomyositis, but rarely in thighs, calves, gluteal area and lower abdomen. Almeida MSTM, Lima SCB, Carvalho LL, Almeida JVM, Santos LG, Rolim JRA, Rocha TE. Panniculitis–An unusual cutaneous manifestation of systemic sclerosis.     

Subcutaneous porocarcinoma clinically presenting as a soft tissue tumor

Porocarcinoma is a rare malignancy with glandular adnexal differentiation. A 38‐year‐old Japanese man noticed a subcutaneous mass in right inguinal region about 20 years prior to being examined. Radiological examinations demonstrated the mass, 11 × 10 cm in size, was in the subcutaneous fat tissue. Recently, the mass grew rapidly, and it was biopsied by an orthopedist based on clinical diagnosis of primary soft tissue tumor. Histopathological examination of the resected specimens also revealed that the tumor lacked involvement to the skin. Microscopically, the tumor was mainly composed of poroid cells with partially obvious squamous differentiation, accompanied by focal ductal structures immunoreactive for CEA and EMA. The tumor contained a low‐grade area consisting of poroid cells and high‐grade area with squamous differentiation. This histopathological heterogeneity suggested malignant transformation from poroma. The patient had the tumor in almost same size over the period of 20 years, which is the longest in the previous reports. This unique case of subcutaneous porocarcinoma is reported.     

Linear Lupus Erythematosus Profundus as an Initial Manifestation of Systemic Lupus Erythematosus in a Child

The case of a 13‐year‐old Caucasian girl with a 1‐year history of a linear plaque on her thigh is reported. Histopathologic examination of the incisional biopsy tissue established the diagnosis of lupus erythematosus panniculitis. Six months later she developed the clinical and laboratory criteria for the diagnosis of systemic lupus erythematosus (SLE). She was treated with azathioprine and oral prednisolone, with a favorable clinical outcome. Our case illustrates a child with linear lupus erythematosus profundus as an initial manifestation of SLE. To our knowledge, only eight other cases of linear lupus erythematosus profundus have been reported in the literature, five in children. In contrast to our patient, none of those cases progressed to SLE during the reported follow‐up period. The authors report this case to illustrate an unusual superimposed segmental manifestation of an inflammatory polygenic disorder.     

Sclerosing postirradiation panniculitis

Sclerosing postirradiation panniculitis is an unusual variant of panniculitis that appears as a complication of megavoltage radiotherapy. Most patient are women with a history of breast cancer who develop nodular lesions on the anterior chest skin several months after receiving megavoltage therapy for breast carcinoma. Sclerosing postirradiation panniculitis is an unusual cutaneous complication of megavoltage radiotherapy that should be distinguished from subcutaneous metastatic disease, cellulitis, and connective tissue diseases involving the subcutaneous fat. The differential diagnosis can be established on the basis of the characteristic histopathologic features.     

Composite cutaneous lymphoma of diffuse large B‐cell lymphoma‐leg type and subcutaneous panniculitis‐like T‐cell lymphoma

Composite lymphoma (CL) is a rare disease defined by the occurrence of two distinct lymphomas within a single tissue at the same time. We present the case of an 89‐year‐old male with a clinical history of immunoglobulin M monoclonal gammopathy of undetermined significance. The patient presented cutaneous eruption of nodules on the right bottom and arm. An excisional biopsy revealed cutaneous infiltration composed of two components. The first one consisted of large B‐cells with CD20+/MUM1+/BCL2+ phenotype whereas the second one involved the subcutaneous fat in a panniculitic manner, and was CD3+/CD8+/granzyme B+/TCRβF1+. The final diagnosis was CL of primary cutaneous large B‐cell lymphoma‐leg type (PCLBCL‐leg type) and subcutaneous panniculitis‐like T‐cell lymphoma (SPTCL). We report and characterize for the first time coexistent PCLBCL‐leg type and SPTCL in a patient.     

Sweet's syndrome--like neutrophilic lobular panniculitis associated with all-trans-retinoic acid chemotherapy in a patient with acute promyelocytic leukemia

Sweet's syndrome-like (Sweet's-like) neutrophilic panniculitis is usually idiopathic, but is frequently associated with hematologic, inflammatory, and immunologic disease. Drug-related cases of Sweet's syndrome have been reported. Of relevance, chemotherapy with the retinoid all-trans-retinoic acid (ATRA) infrequently induces Sweet's-like neutrophilic panniculitis that occurs concomitantly with neutrophilic differentiation. The pathologic features are limited to the adipose tissue or include both the dermis and the subcutaneous fat; the neutrophilic infiltrate can be observed in the lobules, the septae, or both. We present this case because of the unusual subcutaneous neutrophilic infiltrate consistent with Sweet's-like neutrophilic lobular panniculitis in a patient with acute promyelocytic leukemia receiving ATRA chemotherapy. This case highlights the important connection between ATRA and Sweet's syndrome.     

Sweet's syndrome with subcutaneous involvement associated with pegfilgrastim treatment: first reported case

Neutrophilic panniculitis is an infrequent entity, considered by most authors as part of the ‘neutrophilic dermatosis’ spectrum. Few cases have been reported to be related with granulocyte colony‐stimulating factor (G‐CSF); we report a case of neutrophilic panniculitis and Sweet's syndrome lesions related with pegfilgrastim, a long‐acting G‐CSF. A 77‐year‐old woman with M2 acute myeloid leukemia was treated with chemotherapy as well as broad‐spectrum antibiotics and antifungal drugs because of febrile neutropenia. Ten days after a single dose of pegfilgrastim, she developed a limited number of purple plaques on the neck, left leg, both arms and several indurated and slightly mobile nodules on her forearms. Skin biopsy of a plaque showed a diffused dermal neutrophilic infiltrate with dermal edema. Biopsy of a nodule showed a lobular neutrophilic panniculitis without vasculitis. No foreign material was found in those biopsies. No organisms were detected in blood, urine or tissue cultures. She was started with prednisolone 40 mg once a day, with dramatic improvement within the next 2 days. This case is noteworthy for the simultaneous appearance of Sweet's syndrome and neutrophilic panniculitis and it is the first case of neutrophilic panniculitis associated with this drug, pegfilgrastim.     

Infection and panniculitis

Infection‐induced panniculitis may result from a number of microbes including bacteria, fungi, and parasites. Viruses have also been implicated as a cause. This type of panniculitis can occur as a primary infection by direct inoculation of infectious microorganisms into the subcutaneous tissue, or secondarily via microbial hematogenous dissemination with subsequent infection of the subcutaneous tissue. Panniculitis is rarely viewed solely in terms of infectious causes. Also, subcutaneous infections are infrequently viewed in terms of infection‐induced panniculitis but rather as cutaneous infections with subcutaneous involvement. Little information exists specifically on the subject of infection‐induced panniculitis outside of the realm of case reports and case series. In this review, the present authors address panniculitis from the vantage point of infectious causes, focusing on those microorganisms with infection‐induced panniculitis reports in the literature. Diagnosis and treatment are also discussed.     

Disseminated ulcerating lupus panniculitis emerging under interferon therapy of hairy cell leukemia: Treatment‐ or disease‐related?

We report a 43‐year‐old woman, who underwent therapy with interferon‐α for hairy cell leukemia. During interferon‐α therapy she developed multiple subcutaneous swellings, accompanied by fever and fatigue. A skin biopsy revealed lobular, T‐cell lymphocytic panniculitis. In conjunction with the clinical and immunological findings, the diagnosis of lupus panniculitis was made and interferon‐α therapy stopped. Initially, she responded well to oral prednisone and hydroxychloroquine, but after several months she became resistant to it. Her condition worsened, she developed skin ulcers in the inflamed regions. Only with the leukemia‐targeted therapy using cladribine and rituximab her skin condition could be controlled, suggesting hairy cell leukemia as an additional trigger of the lupus panniculitis. Our report is the first one to show induction of lupus panniculitis under interferon therapy of hairy cell leukemia and its presumable sustentation by the latter.     

Post‐steroid panniculitis in an adult

Post‐steroid panniculitis is known to be very rare and most of the reported cases have been in children after corticosteroid therapy. We present a case of post‐steroid panniculitis occurring in a 60‐year‐old man after massive, long‐term administration of corticosteroids for acute exacerbation of chronic obstructive pulmonary disease (COPD). Histopathological examination of a nodule revealed a patchy area of fat necrosis, several multinucleated giant cells containing needle‐shaped clefts. The lesions subsided completely in approximately 12 weeks without any treatment. We suggest that post‐steroid panniculitis is not confined to childhood but also occurs in adulthood.     

Subcutaneous sweet syndrome

Neutrophilic panniculitis encompasses a heterogeneous group of diseases histopathologically characterized by an inflammatory infiltrate in the subcutaneous fat mainly composed of mature neutrophils. This group of panniculitides includes alpha(1)-antitrypsin deficiency, infectious panniculitis, factitious panniculitis, subcutaneous Sweet syndrome, neutrophilic/pustular panniculitis associated with rheumatoid arthritis, erythema nodosum-like lesions of Beh?et disease, bowel bypass panniculitis, and iatrogenic panniculitis. This article reviews subcutaneous Sweet syndrome, which is a rare idiopathic panniculitis characterized by a dense neutrophilic infiltrate in the subcutis and is often related to hematologic malignancies. The relationship of subcutaneous Sweet syndrome and erythema nodosum is discussed as well as the differential diagnosis with other neutrophilic panniculitis.     

A Case of Sweet's Panniculitis Associated with Spinal Metastasis from Prostate Cancer

Sweet''s panniculitis is a rare variant of Sweet''s syndrome in which neutrophilic infiltrate can be found either in the subcutaneous fat or in both the dermis and the subcutaneous tissue. Due to the rarity of this entity, the association between Sweet''s panniculitis and malignancies is inconclusive, but cases of Sweet''s panniculitis have largely been associated with hematological malignancies. Herein, we present a case of Sweet''s panniculitis accompanied by bone metastasis from prostate cancer. Clinicians should be aware that Sweet''s panniculitis may be associated with malignancies of solid organs.     

Subcutaneous Panniculitis‐Like T‐Cell Lymphoma in Children: A Review of the Literature

Subcutaneous panniculitis‐like T‐cell lymphoma (SPTCL) is a type of skin lymphoma. Pleomorphic T‐cells infiltrate the subcutaneous tissue and mimic lobular panniculitis. We report a case occurring in a 12‐year‐old Chinese boy who presented with multiple indolent erythematous subcutaneous nodules on both extremities without systemic symptoms. He had a protracted course of multiple erythematous subcutaneous nodules for 1 year and underwent biopsy of lesional skin for histology and T‐cell receptor (TCR) gene analysis. Histopathology showed infiltration of medium to large atypical pleomorphic cells involving the subcutis with characteristic rimming of fat spaces. TCR gene rearrangement shows monoclonal rearrangements of the TCR β and γ chains. Immunophenotypic studies showed that CD3, CD4, and CD8 were strongly and diffusely positive in lesional cells and that CD56 was focally positive. In contrast, these cells were negative for CD20, CD30, and CD68. The combined morphology, characteristic histologic features, and positive T‐CR gene rearrangement supported a diagnosis of SPTCL. He is being treated with combination chemotherapy of cyclophosphamide, doxorubicin, vincristine, and prednisolone.     

Gouty panniculitis in a 68‐year‐old man: case report and review of the literature

Background Gouty panniculitis is a very rare disease. To date, only eight patients have been reported. In each case, time to diagnosis was lengthy. We describe a 68‐year‐old man with a 6‐month history of tender, erythematous plaques and nodules involving the anterior aspects of the legs Methods and results Histologic examination led to the diagnosis of gouty panniculitis. Conclusion Review of the literature and the present case suggests that hyperuricemia is a necessary but probably not sufficient condition for gouty panniculitis. Why gouty panniculitis very seldom arises as a manifestation of gout is puzzling. In almost all reported patients, uricostatic or uricosuric therapy leads to clinical improvement of the disease.     

Lupus erythematosus panniculitis presenting as palpebral edema and parotiditis

Lupus erythematosus panniculitis or lupus erythematosus profundus is characterized by inflammation of the deep dermis and subcutaneous tissue. It can occur in isolation or associated with chronic systemic or discoid lupus erythematosus. It usually consists of nodules and hardened subcutaneous plaques on the forehead, cheeks, proximal extremities, and buttocks. Periorbital and parotid involvement are rare and can lead to misdiagnosis. We present the case of a patient with lupus erythematosus panniculitis who presented with palpebral edema and involvement of the periocular fat and parotid gland.     

Vemurafenib‐Induced Neutrophilic Panniculitis in a Child with a Brainstem Glioma

Neutrophilic panniculitis is a rare adverse effect of therapy with selective BRAF inhibitors. We report a case of neutrophilic panniculitis in a 15‐year‐old girl receiving treatment with vemurafenib for a brainstem glioma. Clinicians should be aware of this rare but important side effect of vemurafenib. This is the first report of neutrophilic panniculitis in a child treated with vemurafenib.     

Dermal desmoplastic fibroblastoma presenting as a large sacral mass

Desmoplastic fibroblastoma (collagenous fibroma) is a rare and recently recognised benign tumour. Most desmoplastic fibroblastomas arise in the subcutaneous tissue or skeletal muscle. Involvement of the dermis is extremely rare. We describe an unusual case of dermal desmoplastic fibroblastoma presenting as a large sacral mass in a 16‐year‐old male. An awareness of this entity is necessary to avoid confusion with other benign and malignant soft tissue neoplasms.     

Neutrophilic panniculitis arising from hematogenous spread of methicillin-resistant Staphylococcus aureus

Infectious panniculitis from hematogenous spread is uncommon and usually occurs in immunocompromised patients. Dissemination of gram-positive organisms to the subcutaneous tissue is rare with only several reports of disseminated panniculitis caused by Streptococcal species. We report a case of an immunocompetent 2-year-old boy presenting with diffuse neutrophilic panniculitis arising from methicillin-resistant Staphylococcus aureus septicemia. This case represents a highly atypical manifestation of severe MRSA infection and serves as a reminder to consider MRSA as a cause of disseminated neutrophilic panniculitis, particularly in high-risk populations.