Inflammatory myofibroblastic tumor on intercostal nerve presenting as paraneoplastic pemphigus with fatal pulmonary involvement

18F-FDG PET/CT in Follicular Dendritic Cell Sarcoma With Paraneoplastic Pemphigus as the First Manifestation

A 48-year-old woman presented with refractory oral ulcers and skin rashes on the palms and trunk, diagnosed as paraneoplastic pemphigus. The chest x-ray revealed a mass in the right lower chest, and the F-FDG PET/CT scan showed the lesion in the right anterior-inferior mediastinum with intense F-FDG uptake, accompanied by right parasternal adenopathy and pleural effusion. The surgical pathology proved a follicular dendritic cell sarcoma, with right parasternal lymph node metastasis.

Paraneoplastic Pemphigus with Underlying Retroperitoneal Inflammatory Myofibroblastic Tumor: A Case Report and Review of the Literature

Inflammatory myofibroblastic tumor (IMT) is a peculiar low-grade neoplasm of spindle cell fibroblasts and myofibroblasts in an inflammatory background. The lung is the most common site of involvement. Here, we report a case of paraneoplastic pemphigus (PNP)-associated with an extensive retroperitoneal IMT. The patient had a favourable response following treatment with a low dose of systemic steroid, mycophenolate mofetil, and intravenous immunoglobulin (IVIG). He subsequently underwent surgery for resection of the tumor with nephrectomy and five courses of IVIG were administered after surgery due to a minor relapse. He was in remission in her last follow-up visit 16 months after surgery. The occurrence of PNP with IMT is notable; early detection and treatment are crucial for this tumor-associated autoimmune disease.

Paraneoplastic pemphigus as a first sign of metastatic retroperitoneal inflammatory myofibroblastic tumor: (18)F-FDG PET/CT findings

A 30-year-old female presented with a 3-month history of erosive stomatitis and bullous lesions, along with recurrent episodes of abdominal pain. She was found to have a retroperitoneal lump in left lumbar region. Skin biopsy revealed bullous disorder. CT guided biopsy of the retroperitoneal mass was suggestive of inflammatory myofibroblastic tumor (IMT). She was started on oral steroids and supportive care, and surgery was being planned when she developed respiratory failure. CT chest revealed vertebral metastases. PET/CT for whole body work up revealed a left para-aortic mass along with multiple skeletal metastases. The patient was kept on conservative management. After 3 months, the patient has shown clinical improvement, and an exploratory laparotomy is now being planned for the excision of the tumor, followed by chemotherapy. This case of retroperitoneal IMT is rare in terms of skeletal metastases with paraneoplastic pemphigus.

Neural system antigens are recognized by autoantibodies from patients affected by a new variant of endemic pemphigus foliaceus in Colombia

BACKGROUND

Endemic pemphigus foliaceus (EPF), is also known as "fogo selvagem" or "wild fire," reflecting the intense burning sensation of the skin reported by patients with this disease. Based on this finding, we tested for neural autoreactivity in patients affected by a new variant of EPF (El Bagre-EPF).

METHODS

We tested 20 El Bagre-EPF patients, 20 normal controls from the endemic area, and 20 age- and sex-matched normal controls from outside the endemic area. We tested for autoreactivity to several immunoglobulins and complement. Both human skin and bovine tail were used as antigens.

RESULTS

We detected autoreactivity to neural structures, mechanoreceptors, nerves, perineural cell layers of the arachnoid envelope around the optic nerve, brain structures, and to neuromuscular spindles; these structures colocalized with several neural markers. The patient antibodies also colocalized with desmoplakins 1 and 2, with the armadillo repeat protein deleted in velo-cardio-facial syndrome and with p0071 antibodies. Autoreactivity was also found associated with neurovascular bundles innervating the skin, and immunoelectron microscopy using protein A gold against patient antibodies was positive against the nerve axons. Paucicellularity of the intraepidermal nerve endings and defragmentation of the neural plexus were seen in 70% of the cases and not in the controls from the endemic area (p<0.005). Neuropsychological and/or behavioral symptoms were detected in individuals from the endemic area, including sensorimotor axonal neuropathy.

CONCLUSIONS

Our findings may explain for the first time the "pose of pemphigus," representing a dorsiflexural posture seen in EPF patients vis-a-vis the weakness of the extensor nerves, and furthermore, the autoreactivity to nerves in EPF could explain the "burning sensation" encountered in EPF disease.