Primary Cutaneous B-Cell Lymphoma, Leg Type Restricted to the Subcutaneous Fat Arising in a Patient With Dermatomyositis

Inflammatory myopathies and lymphoma

The inflammatory myopathies comprise a group of immune-mediated muscle diseases. Lymphoma is a term for a variety of lymphatic system malignancies. Autoimmune diseases and lymphoproliferative malignancies share a complex bidirectional relationship. A causal relationship between inflammatory mypathies and lymphoma has not been established. The diagnosis/treatment of inflammatory myopathy usually precedes the detection/diagnosis of lymphoma. Immune system dysregulation presumably underlies the evolution of lymphoma in patients with inflammatory myopathies. Inflammatory activity with chronic B-cell activation and/or antigen stimulation is deemed the major risk factor for lymphoma in patients with autoimmunity. A "paraneoplastic" phenomenon or the effects of immunosuppressive therapy may be alternative immune-based mechanisms. In chronic lymphocytic leukemia immune system disturbance rarely results in non-hematological autoimmune disease, including inflammatory myopathies.

Primary Marginal Zone Lymphoma of the Subcutis Associated With Panniculitis and Fat Necrosis

OBJECTIVES

Lymphocytic infiltrates in the subcutaneous adipose tissue, often accompanied by fat necrosis, are typically seen in benign panniculitis. Diagnostic considerations include subcutaneous panniculitis-like T-cell lymphoma and cutaneous γδ T-cell lymphoma, whereas a primary subcutaneous B-cell lymphoma in this setting has not been previously described.

METHODS

We report the case of a 72-year-old woman with multiple deep cutaneous nodules on the trunk and upper extremities.

RESULTS

During 3 years of clinical follow-up, new skin nodules developed, while existing lesions remained stable or regressed. No other organ involvement was detected. Sequential biopsy specimens of the subcutaneous lesions revealed patchy, predominantly septal, lymphocytic infiltrates associated with extensive hyaline fat necrosis. The histologic and immunophenotypic features were consistent with marginal zone lymphoma. Genotyping revealed an identical monoclonal immunoglobulin gene rearrangement across all biopsy specimens.

CONCLUSIONS

This case represents, to our knowledge, the first reported case of primary subcutaneous B-cell lymphoma closely associated with panniculitis.

Hematological malignancy associated with polymyositis and dermatomyositis

The aims of this present study were to: 1) assess the characteristics of hematological malignancies in polymyositis/polymyositis (PM/DM) patients; and 2) determine predictive variables of hematological malignancies in PM/DM patients. We retrospectively reviewed the medical records of 32 patients (14 PM, 18 DM) associated with hematological malignancies. In our 32 PM/DM patients, hematological malignancy was concurrently identified (18.8%) or occurred during the course of PM/DM (31.2%); although, PM/DM more often preceded hematological malignancy onset (50%). We observed that the types of hematological malignancies varied, consisting of: B-cell lymphoma (n=20), T-cell lymphoma (n=4), Hodgkin's disease (n=2), multiple myeloma (n=1), myelodysplastic syndrome without excess of blasts (n=3), hairy cell (n=1) and acute lymphocytic leukemia (n=1). In 21 patients of our 32 patients with PM/DM-associated hematological malignancy (65.6% of cases), PM/DM paralleled the course of hematological malignancy. Finally, we observed that patients with PM/DM-associated hematological malignancies had a poor prognosis, the survival status ranging from 96.9%, 78.1% and 51.4% at 1, 3 and 5years, respectively. Interestingly, we found that patients with hematological malignancies, compared with those without were older and more frequently had DM; on the other hand, these patients less commonly exhibited: joint involvement (p=0.017), interstitial lung disease (p=0.06) and anti-Jo1 antibody (p=0.001). Taken together, our study underscores that the association between PM/DM and hematological malignancy, especially lymphoma, should not be ignored. Our findings also suggest that antisynthetase syndrome may be a protective factor of hematological malignancy in PM/DM patients.

Panniculitis Ossificans of the Lower Leg

The authors present a rare case of panniculitis ossificans (PO) in a 30-year-old woman. Differential diagnoses and treatment are discussed. PO is an important differential diagnosis to sarcomas.