# Midline Destructive Lesions: Differentiating Granulomatosis With Polyangiitis From Cocaine-Induced Perforations

## TL;DR

This paper discusses a case where a patient's midline destructive lesions were diagnosed as GPA, not caused by cocaine use, highlighting diagnostic challenges and the importance of considering autoimmune conditions.

## Contribution

The paper presents a case emphasizing the need to consider GPA in patients with midline destructive lesions despite a history of cocaine use.

## Key findings

- A patient with a history of cocaine use was diagnosed with GPA based on C-ANCA positivity and response to immunosuppressive therapy.
- Midline destructive lesions can be caused by GPA and not solely by cocaine use, requiring careful differential diagnosis.
- Systemic symptoms and laboratory results were critical in confirming GPA despite initial biopsy limitations.

## Abstract

Granulomatosis with polyangiitis (GPA) is a rare autoimmune vasculitis that may present with midline destructive lesions, often overlapping with conditions such as cocaine-induced midline destructive lesions (CIMDL).

A 56-year-old man with a history of significant cocaine use (1 gram twice a week for three years, abstinent for five years) presented with chronic nasal congestion and epistaxis. He developed a large nasal septal perforation and later a palatal perforation. Laboratory workup revealed positive cytoplasmic antineutrophil cytoplasmic antibody (C-ANCA) with elevated proteinase 3 (PR3) levels, supporting the diagnosis of GPA. Despite an initial lack of granulomatous inflammation on biopsy, the patient's clinical presentation and positive response to immunosuppressive therapy confirmed GPA as the correct diagnosis.

This case highlights the complexity of diagnosing GPA in a patient with a history of cocaine use. The positive C-ANCA result, systemic symptoms, and response to immunosuppressive treatment were key in establishing the diagnosis. It underscores the importance of considering GPA in the differential diagnosis of midline destructive lesions, even in the context of a history of cocaine use, and the need for timely and multidisciplinary management.