A 70 year old female underwent a bone marrow trephine biopsy from the posterior superior iliac spine using Jamshidi needle during investigation for long standing anemia and thrombocytopenia. Histology of the trephine biopsy specimen showed mild erythroid hyperplasia and dysplastic megakaryoctes. Few glandular elements were present at one end of the trephine biopsy specimen composed of cuboidal cells surrounding central lumina. Nuclei were bland with no evidence of pleomorphism or mitotic activity.((Image 1)

On high power examination, a second attenuated layer of myoepithelial cells was seen surrounding the cuboidal cells in several of the glandular structures (Image 2). There was no associated stromal dysplasia. Immunohistochemical staining with CK demonstrated the cells lining glandular lumina to be strongly positive.

The patient did not have any history of weight loss but was on treatment for Rheumatoid arthritis since 20 years; clinical and limited radiological examination did not reveal a primary malignancy. These non-neoplastic glandular structures were an artifact produced during trephine biopsy procedure.  Pathologists and hematologists should consider non-neoplastic glandular structures in cases where epithelial elements show bland nuclear features and an absence of stromal desmoplasia if a serious misdiagnosis of metastatic malignancy and unnecessary investigation is to be avoided. Such epithelial elements are likely to be of dermal sweat gland origin.