BackgroundBreast carcinoma with osteoclast-like giant cells (OGCs) is infrequent, being most reported cased described as ductal invasive carcinomas. Invasive pleomorphic lobular carcinoma (PLC) is a distinct morphological variant of invasive lobular carcinoma characterized by higher nuclear atypia and pleomorphism than the classical type. In the best of our knowledge, a PLC with OGCs has not been previously reported.Case presentationWe report the case of a 72-year-old woman presenting with a pleomorphic tumor of the left breast with a dense infiltration by OGCs and T lymphocytes with a 10:1 predominance of CD8+ over CD4+ cells. The diagnosis of a lymphoid or mesenchymal neoplasia was excluded after demonstrating keratin expression by the neoplastic cells. The absence of E-cadherin expression and the morphological features were consistent with the diagnosis PLC with OGCs. In addition, we demonstrated the deleterious mutation C.del866C in CDH1gene, but no mutations in any of the other 33 genes analyzed by next generation sequencing.ConclusionsBreast carcinoma with stromal osteoclast-like giant cells is a very rare tumor, for that reason, the use of the cytologic features and growth patterns in combination with immunohistochemically studies is mandatory for a correct diagnosis of lobular carcinoma. In addition, further studies are necessary to clarify the influence of OGCs in the prognosis of these patients.Electronic supplementary materialThe online version of this article (10.1186/s13000-018-0744-6) contains supplementary material, which is available to authorized users.

Lymphomatoid papulosis type E (LyP) is a recently described subtype of LyP characterized by an angioinvasive infiltrate of atypical lymphocytes expressing CD30. We present a case of type E LyP with extensive cutaneous necrosis in the histopathological evaluation which was misdiagnosed as an ulcerative form of bacterial skin infection. The remarkable cutaneous necrosis showed in our case might be related to the angiodestructive infiltrate that was present in this circumstance.