Paraneoplastic granulomatous eruption
CPGE may be morphologically variable. Cases of palisading neutrophilic granulomatous dermatitis (PNGD) and interstitial granulomatous dermatitis (IGD) have been well described. PNGD is most frequently associated with autoimmune connective tissue disease, such as rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), but PNGD has also been reported in association with MDS and other lymphoproliferative conditions. It may precede the malignancy diagnosis by up to 5 years, or it may be present at the time of diagnosis.
Interstitial granulomatous dermatitis with arthritis (IGDA) has been associated with a range of hematologic malignancies (including leukemia, lymphoma, MDS, and polycythemia vera), bronchial and esophageal squamous cell carcinoma (SCC), nonneoplastic rheumatologic disease (most commonly RA), and medications (eg, tumor necrosis factor [TNF]-alpha inhibitors, beta blockers, angiotensin-converting enzyme [ACE] inhibitors).
Disseminated granulomatous eruptions with granuloma-annulare-like and sarcoidal histopathologic features have been reported in the setting of MDS.
However, no causative relationship between granuloma annulare (GA) and hematologic and solid organ malignancies has been clearly established. Seven patients who developed GA within 6 months of a solid organ malignancy diagnosis or in whom GA resolved with solid organ malignancy treatment exhibited widespread skin involvement with a prominent perivascular infiltrate on histopathology.
The exact pathogenesis of CPGE is not yet well understood. It has been postulated that the dysregulated T-cell response seen in MDS (predominance of regulatory T-cells over Th17 cells) was reflected in the associated cutaneous granulomatous eruption.
L92.8 – Other granulomatous disorders of the skin and subcutaneous tissue
708040001 – Granulomatous lesion
Differential Diagnosis & Pitfalls
- PNGD or IGD secondary to connective tissue disease or a drug cause
- Generalized granuloma annulare
- Cutaneous metastases
- Leukemia cutis
- Cutaneous atypical mycobacterium infection – Varies in clinical manifestation; suggestive history of tuberculosis (eg, foreign native, prisoner), leprosy (nerve involvement, endemic travel), or other atypical mycobacterium infection (eg, marine water contact).
- Granulomatous secondary syphilis
- Histiocytoid Sweet syndrome
- Cutaneous T-cell lymphoma