Occurrence of a granulomatous mastitis and aseptic osteitis after anti-TNF therapy in a patient with pustular psoriasis

Idiopathic granulomatous mastitis: case series and clinical review

Idiopathic granulomatous mastitis is a chronic inflammatory breast disorder that typically affects young, parous women, often following lactation. Patients present with tender, erythematous breast lesions with histological evidence of non-caseating granulomata and an inflammatory cell infiltrate. An immune-mediated pathophysiology is hypothesised and an association with lipophilic Corynebacterium species is observed. Initial diagnosis is often delayed due to lack of awareness of the condition and management of refractory disease can be challenging. We present an extensive case series of patients collaboratively managed by subspecialty physicians and surgeons at a single centre in Sydney, Australia. The accompanying review expands on features of this condition and supports the utility of a multidisciplinary approach.

Clinical study on surgical treatment of granulomatous lobular mastitis

Background

The etiology and pathogenesis of granulomatous lobular mastitis (GLM) remain unknown, with no unified evaluation criteria or standard treatments. This study aimed to assess the etiology and features of GLM, as well as the effects of surgery (lesion excision + stage I breast reconstruction; LE + BR) for GLM.

Methods

This study evaluated 178 female GLM patients retrospectively in 2006-2015. The surgery and non-surgery groups included 164 and 14 patients, respectively. All patients received conservative therapy (traditional Chinese medicine combined with regional wet compress and pus drainage). In addition, the surgery group (n=164) underwent LE + BR. Clinical data, including disease course, causes, lesion size, marital status, and treatment approaches, were assessed.

Results

Follow-up was 13-117 months. Seventy-five of the 178 patients had no overt causes (42.1%); meanwhile, 63 (35.4%) and 16 (9.0%) had congenital nipple retraction and a history of psychotropic drugs for >1 year, respectively. The surgery group showed lesions significantly shrunk (≤1 quadrant) with acute inflammation fully controlled; 8 showed recurrence, indicating a cure rate of 95.1% (156/164). In the non-surgery group, 4 cases showed relapse after 6-14 months (cure rate =71.4%; 10/14). Therefore, surgical treatment was significantly more efficient than non-surgical treatment (P=0.001). Kaplan-Meier survival curves for the two treatment types showed a significant difference in recurrence (log rank =11.84, P<0.001).

Conclusions

In GLM patients, LE + BR is safe and effective with respect to cosmetic results, recovery time, and recurrence. Successful surgery should be performed for patients whose lesions ≤1 quadrant, aim to achieve optimal GLM treatment.

SAPHO, autophagy, IL-1, FoxO1, and Propionibacterium (Cutibacterium) acnes

Overt infection by Propionibacterium acnes is lacking in many SAPHO syndromes, and antibiotics have only a transient and incomplete effect, either in SAPHO syndrome or acne. As several auto-inflammatory bone disorders sharing overproduction of IL-1β can mimic SAPHO, this syndrome could partly depend on genetically encoded overproduction of IL-1β. However, cyclic intracellular infections, mostly by P. acnes, can contribute to the enhanced IL-1β release by some skin cells, and probably by bone cells. P. acnes is indeed a powerful trigger of NLRP3-inflammasome activation and IL-1β, leading to osteitis and enhanced mesenchymal cells differentiation in osteoblasts. Recent advances in the understanding of acne suggest that first steps of this disorder are not driven by P. acnes, but by a relative deficiency of FoxO1 within the nucleus of sebaceous cells. A similar defect of FoXO1 in bone cells should also be sought in SAPHO, since repression of FoxO1 gene is found in lesional psoriasis skin, and is associated with an increased number of osteoblasts and high bone mass in mice. FoxO1 selectively promotes IL-1β production, so that its downregulation could help some P. acnes t escape innate immunity and persist in a latent state in bone cells, including mesenchymal stem cells. However, P. acnes itself possibly contributes to FoxO1 downregulation, like H. pylori infection which induces nuclear inactivation of FoxO1 in human gastric cells to slow down autophagic clearance. As bisphosphonates, which often improve SAPHO syndromes, enhance autophagy, it may be worth testing whether their combination with antibiotics is synergistic in SAPHO syndromes.