Case Presentation: A 69-year-old male with no significant medical history presented to his primary care provider with a 6-week history of progressive rash with painful lesions involving the oral mucosa, face, scalp, back, arms, legs, and groin. The condition was initially treated as a fungal process. In the setting of rapidly progressive oral erosions and cutaneous bullous lesions, the patient presented to an emergency room for further care. Due to additional complaints of constipation, 30-pound weight loss over 2 months, lethargy, and generalized malaise, a computed tomography (CT) of the abdomen and pelvis was performed. CT revealed an 18- centimeter (cm) retroperitoneal mass, left-sided hydronephrosis, retroperitoneal lymphadenopathy, and a left-sided pleural effusion. Routine labs were unremarkable. A punch biopsy of a left shoulder lesion revealed suprabasilar acantholysis. A thoracentesis was performed with pleural fluid cytology revealing high-grade B cell lymphoma. A biopsy of the retroperitoneal mass confirmed follicular lymphoma. Based on the clinical features and histopathology, the dermatologic manifestations were confirmed to be paraneoplastic pemphigus (PNP) related to lymphoma. Following high-dose intravenous corticosteroids, urgent systemic chemotherapy was initiated with Rituximab, Cyclophosphamide, Doxorubicin, Vincristine, and Prednisone (R-CHOP) with stabilization of the condition.
Discussion: PNP is a rare, often fatal mucocutaneous disease process most commonly induced by an untreated lymphoproliferative disorder. PNP accounts for 3-5% of all pemphigus cases and has a 90% mortality rate. Humoral and cell-mediated immune responses are triggered by the neoplastic process leading to an inflammatory response. The hallmark feature of PNP is the development of severe, erosive stomatitis which is almost always present. Cutaneous manifestations present variably with skin ulcerations, diffuse erythema, bullae, and scaly plaques. PNP may also affect the respiratory system with the development of bronchiolitis obliterans and obstructive lung disease. The diagnostic criteria include clinical features, histopathology, direct/indirect immunofluorescence, and/or immunoprecipitation. First- line therapy is high-dose corticosteroids often followed by monoclonal antibodies.
Conclusions: In patients presenting with erosive stomatitis with painful cutaneous lesions, this case demonstrates a rare presentation of PNP related to undiagnosed follicular lymphoma. Early suspicion and recognition of PNP could lead to palliation of symptoms and an overall improvement in associated morbidity related to an untreated malignancy. This case serves to raise awareness amongst hospitalists that progressive mucocutaneous findings can be malignant in nature requiring urgent treatment of underlying disease.