Sarcoidosis of the breasts – when should it be considered? A case report

Given the heterogeneity of presentations, the diagnosis of sarcoidosis is a challenge to both clinicians and diagnosticians. Multiorgan involvement, varied imaging findings and diverse clinical features frequently contribute to prolonging the time to diagnosis. Serious complications of untreated sarcoidosis include pulmonary fibrosis, cardiac arrhythmias, and damage to the central nervous system⁽¹⁾. Therefore, prompt diagnosis is crucial for the further clinical course of the disease. The reported case shows that individualised approach is required of medical teams to achieve satisfactory treatment outcomes.

A 44-year-old woman, who had annual prophylactic breast ultrasound scans, without any complaints or palpable breast lesions, presented for a breast ultrasound during lactation. The examination revealed a few small focal lesions with uneven margins, up to 7 mm in size, arranged in a non-parallel configuration, with small blood vessels along their periphery. The foci were characterised by reduced echogenicity, with no enhancement or acoustic shadow visible behind the lesions. The foci were located primarily in the outer quadrants of both breasts. No calcifications were seen within the lesions, and on ultrasound elastographic images they all appeared soft (E_max <20 kPa) (Fig. 1A–C). In addition, enlarged hypoechoic lymph nodes, up to 21 mm in length, with thickened, hypoechoic cortical layers, up to 4 mm thick, with preserved rich hilar vascularisation and no visible sinuses, were identified in both axillary fossae (Fig. 1D). On mammography, glandular structures were predominant, without abnormal thickening or microcalcifications.

Fig. 1

In view of the presence of numerous solid lesions in both breasts, the first step involved performing a core-needle biopsy (CNB) of the dominant lesion. Using a 14G needle, three core specimens were taken. The presence of malignant tumour cells was ruled out. Multiple granulomas with multinucleated giant cells, without signs of serous necrosis, were identified. The suspicion of granulomatous lobular mastitis (GLM) was raised, to be differentiated with another disease characterised by granulomas. To this end, a test for bacteria of the genus Corynebacterium in the breast material was carried out. The bacteria were not detected. To extend the diagnostic work-up for granulomatous lesions, tissue material was obtained from lymph nodes for histopathological analysis. A CNB procedure was performed using a 14G needle. Three core specimens were taken. Clusters of epithelioid cells with sparse multinucleated giant cells, without features of necrosis, were found. Analysis of the lymph node lesions and the focal lesion in the breast led to the suspicion of sarcoidosis (Fig. 2, Fig. 3). In the next step, the patient was referred for pulmonary consultation. High-resolution computed tomography (HRCT) showed lesions characteristic of sarcoidosis, presenting as small nodules in the middle fields and at the fissures of both lungs (Fig. 4). Histopathological analysis of material taken during bronchoscopy showed fragments of bronchial mucosa with granulomas composed of epithelial and giant cells, without signs of necrosis. Based on these findings, the diagnosis of sarcoidosis was estab

Fig. 2

Fig. 3

Fig. 4

lished. The dynamics of the lesions in the breasts was followed up at intervals of several months, for a total of two years. Over that period, the focal lesions in the breasts shrank and grew again until they resolved completely (Fig. 1E–H). The patient remains under the care of the Outpatient Clinic of Pulmonary Diseases and the Outpatient Clinic of Breast Diseases. At the time of diagnosis, she did not require pharmacological treatment.

Sarcoidosis is an idiopathic systemic inflammatory disorder which typically occurs in individuals between 20 and 40 years of age^(1,2). In 90% of cases, the disease begins in the lungs or mediastinal lymph nodes, but it can manifest in any organ, including the breasts^(3,4). The diagnosis of sarcoidosis relies on three criteria: compatible clinical or

radiologic presentation, histologically confirmed evidence of noncaseating epithelioid granulomas, and exclusion of other diseases with similar findings (presence of granulomas)^(1,5).

In the reported case, the diagnosis of sarcoidosis was further complicated by the unusual location of inflammatory lesions. The literature includes isolated case reports of breast sarcoidosis, accounting for less than 1% of all instances of the disease^(2,6).

Initially, based on the ultrasound findings, a proliferative process within the breast was considered. On ultrasound imaging, the focal lesions in the breasts were consistent with BIRADS 4 category, with a malignancy risk of 2–95%⁽⁷⁾. The procedure of choice was CNB of the dominant breast lesion. Considering that the lesions were numerous and small in size, while the patient was still lactating, it was decided that a single focal lesion would be evaluated, and the histopathological diagnostic work-up would be extended to the remaining lesions, if necessary. In the next stage, in order to specify the type of granulomatous disease, the diagnostic procedure was extended to include CNB of the axillary lymph nodes. The histopathological findings revealing granulomatous lesions without signs of necrosis narrowed down the range of possible pathologies and ruled out their malignancy.

Tuberculous lesions were considered in the differential diagnosis, but the possibility was abandoned based on the identification of noncaseating granulomas. Subsequent diagnostic work-up of pulmonary lesions detected no presence of acid-fast bacilli in the bacteriological examination of bronchoalveolar lavage (BAL)^(8,9).

In view of the suspicion of granulomatous mastitis (GLM), culture of a histopathological specimen was done, excluding infection with bacteria of the genus Corynebacterium. In the absence of clinical signs of breast inflammation, no other inflammatory factor was taken into account in the diagnosis, also considering a different microscopic image^(10,11).

Idiopathic granulomatous mastitis (IGM) is more common in the postpartum period. Even though the patient gave birth two years before the appearance of the breast lesions, she was still lactating at the time of diagnosis. The characteristic manifestations of IGM include lobular mastitis with microabscesses, and inflammatory changes and damage to the mammary ducts^{(12, 13, 14, 15)}. The histopathological material did not show any changes specific to this disease entity.

The results of HRCT of the chest and histopathological examination of the mucosal sample obtained during bronchoscopy confirmed the presence of changes pathognomonic of sarcoidosis. Moreover, by excluding other possible causes of the lesions, all three criteria for the diagnosis of pulmonary sarcoidosis with breast involvement were met.

The diagnosis was additionally confirmed by the clinical course, which was characterised initially by partial and eventually complete remission of the inflammatory lesions. The literature reports show that – depending on the stage – pulmonary lesions may resolve spontaneously in up to 90% of patients⁽⁵⁾. The case reported here, though isolated, is consistent with previous literature findings. Over the two-year follow-up, the patient experienced several remissions of the lesions, followed by their recurrence. Ultimately, the abnormalities resolved completely both in the breasts and axillary lymph nodes.

The reported case provides evidence for the clinical polymorphism of sarcoidosis. The authors highlight the importance of an individualised approach in diagnosing this systemic disease which, if left untreated, results in a significantly reduced quality of life for the patient. Moreover, the development of breast lesions as a primary symptom of the disease emphasises the role of preventive breast ultrasound in women. Good collaboration between diagnosticians, pathologists and clinicians is essential for a successful treatment outcome.