T-cell lymphomas comprise less than 15% of all NHLs.3
Breast T-cell lymphomas are extremely infrequent, reported mainly as isolated cases, but almost all currently recognized subtypes have been described.7–14,18–20
Our cases showed a slightly higher frequency of SBL than PBL, as was also observed in the largest general study of breast lymphomas of Talwalkar et al.9
Lymphomas with secondary breast involvement occur mostly in the context of widespread preexisting nodal or, less frequent, extranodal extramammary primary disease. The frequency of T-cell lymphoma involving the breast varies from 3.4% to 15%.6,9,14,21
The present series of T-cell breast lymphoma is larger than previously reported, accounting to 17.1% of all our breast lymphoma cases.8
The pathogenesis of T-cell lymphoma in the breast is poorly understood, mainly because of its rarity. PBL is reported mostly in postmenopausal women but may appear at any age. These lesions are exceedingly rare in men, and, to the best of our knowledge, our case is the first T-cell PBL reported in a man. Unexplained right side predominance is reported for breast lymphoma in general6,21
; in our patients, 63% of the cases presented on the right side. The typical clinical presentation is as one or multiple painless mass, similar to breast B-cell lymphoma and breast carcinoma; 9 of 11 (81%) of our cases had this presentation. Enlarged ipsilateral axillary lymph node is reported in 13% to 50% of PBL cases9
; we found no cases with this presentation. There are no pathognomonic mammographic features for breast lymphoma in general and sometimes these lesions are only detected by ultrasound.22
ALCL has been reported previously in the breast, more frequently as PBL.6,10,18–20
One of our patients presented an ALCL in her breast adjacent to a silicone breast implant, 6 years after elective breast augmentation. Review of the literature revealed several cases of PBL associated with a breast implant.10,23–27
None of these reported cases presented with clinical features of mastitis as ours. The most common T-cell lymphoma type in close proximity to a breast implant is ALCL. Roden et al24
have proposed a pathogenic mechanism for these cases involving hyperstimulation of T lymphocytes by the silicone, eventually resulting in clonal expansion. Other types of T and B-cell breast lymphoma have been described in association with breast implants, most of them SBL13,28–30
; thus, the causality in the development of breast T-cell lymphoma in association with silicone breast implants is purely speculative.
PTCLs, unspecified, are mainly nodal lymphomas, accounting for more than 50% of all T-cell lymphomas in adults. The breast cases reported have included both PBL and SBL. The clinical outcome of these patients is variable, most of them having aggressive course, but there are reports with very good clinical evolution, applying similar therapeutics regimens.18–20
Our primary PTCL-NOS case showed lymphoepithelial lesion, a rare event that has been previously reported.31
Breast involvement is very rarely seen in precursor T-lymphoblastic lymphoma, particularly as the presenting manifestation.14
When observed, it usually occurs in the context of other systemic disease.4,6,7,18
Involvement of the breast by precursor T-lymphoblastic lymphoma/leukemia presents as a mass or frequently as bilateral diffuse involvement. All our cases showed a well-defined mass, and 2 of them occurred in a setting of leukemic disease.
Adult T-cell leukemia/lymphoma affects adults and it is considered an aggressive disease. Involvement of the breast usually occurs in the course of widespread disease, frequently as bilateral lesions as occurred in 1 of our patients.32
Human T-cell leukaemia virus-I/II infection is present in all regions of Brazil, but its prevalence varies according to the geographical area, being higher in the Northeastern and North regions,33
where 2 of our patients came from.
Extranodal, extracutaneous T-cell lymphomas are very rare; the gastrointestinal tract and nasopharyngeal topographies are the most frequent sites of involvement.1,2
This is the largest series of T-cell lymphomas involving the breast and shows the clinical and histologic heterogeneity of the disease.