Paraneoplastic Autoimmune Multiorgan Syndrome: A Retrospective Study from a Tertiary Care Center in South India

Paraneoplastic autoimmune multiorgan syndrome (PAMS), first described as paraneoplastic pemphigus (PNP) is a heterogeneous autoimmune syndrome with a diverse spectrum of clinical and immunopathological features associated with an internal neoplasm.

The details of the patients diagnosed with PAMS/PNP from an Indian tertiary center between January 2010 to December 2019 were retrieved from the hospital database. The clinical manifestations, histopathological features, immunofluorescence findings, and other relevant clinical details were obtained.

There were eight patients (4 males, 4 females) with PAMS, age ranging from 8 to 46 years (mean 31 years), of whom two were 8-year-old children. The mucocutaneous manifestations were polymorphic and all had recalcitrant oral mucosal involvement. The most common mucosal presentation was pemphigus-like (5/8), and the cutaneous presentation was lichen planus-like (5/8). Castleman's disease (5/8) was the commonest neoplasm followed by thymoma (2/8). Interface dermatitis was seen in all biopsies and three different patterns of direct immunofluorescence were seen, which were intercellular "fish-net" fluorescence in the epidermis (2/8), granular/linear deposition along the basement membrane (4/8) and a combination of both patterns (1/8). Indirect immunofluorescence done on rat bladder in 3 patients showed intercellular "fish-net" fluorescence. Desmoglein levels were not elevated in any of our patients. The follow-up period ranged from 1 to 112.5 months (mean, 23.6 months) with a mortality rate of 12.5%.

In our study, Castleman's disease was the most common associated malignancy, and the mucocutaneous and histopathological findings were heterogeneous. Timely diagnosis and early intervention improved the outcome in our patients.