Sonam, Fnu

Aims . To identify the most common reasons for consultation to a large specialty breast pathology service at a major institution. To provide insight into the overall challenges in practicing breast pathology. Methods . The anatomic pathology database at one institution was searched for all breast consultations received in 2021, excluding in-house patients and patients who were transferring care. Results . A total of 553 patients met the criteria ( n = 553) from a variety of academic and private practices. For each patient, the paperwork from the submitting institution was reviewed to identify the specific question, and subsequently classified into 14 categories. The reason for the consultation request was not provided for 78 (14%) patients, and a review of the outside diagnoses, where applicable, was performed. In summary, the top 5 reasons for consultation were: (1) assistance with classification of atypical intraductal epithelial proliferations (32%); (2) evaluation for the presence of (micro-)invasive carcinoma (14%); (3) evaluation of fibroepithelial (12%), (4) papillary (11%), and (5) spindle cell lesions (7%). Conclusion . We show an ongoing educational and practice gap for pathologists who most commonly struggle with classifying atypical precursor lesions, specifically when these are small and focal, or bordering on intraductal carcinoma (32%, 177/553). The second most common reason for consultation was classifying invasive carcinomas as microinvasive and subtypes (total of 20.4%, 113/553). As such, our data supports the continued need for rigid and clear criteria for diagnosing threshold lesions (namely atypical hyperplasias) and intraductal carcinoma of the breast.

Papillary carcinoma of the breast is a rare histologic subtype of invasive breast cancer. In contrast, ductal carcinoma in situ (DCIS) is a noninvasive, nonobligate precursor to invasive mammary carcinoma, confined within the terminal duct lobular unit of the breast and surrounded by an intact myoepithelial cell layer at the stromal/epithelial interface. We present an unusual case in which a patient with only DCIS of the breast exhibited papillary carcinoma within a sentinel lymph node, leading to questions about the origin of the lymph node lesion—whether it represents a true metastasis or iatrogenic displacement during diagnostic procedures. This case underscores the diagnostic challenges and clinical implications associated with such rare presentations.

Abstract Introduction/Objective Nodal PTCL with EBV positivity can occasionally contain Reed Sternberg-like cells, and EBV- LPD can mimic Hodgkin lymphoma. Coexistence of these two unusual lymphomas in the same lymph node is very rare. We present a case of a 56-year-old male with Composite EBV+ PTCL NOS and EBV LPD, with positive B-cell gene rearrangement and negative T-cell gene rearrangement presenting a significant diagnostic challenge. Methods/Case Report A 56-year-old male with a history of abdominal tuberculosis presented with lethargy, fatigue, and poor appetite. Physical examination revealed generalized lymphadenopathy. CT scan confirmed lymphadenopathy in bilateral axilla, supraclavicular lymph nodes along with lytic lesions on illiac crest. Ill defined splenic lesions raised concerns for metastasis. Cervical lymph node and bone marrow biopsies were performed. Flow cytometry on the lymph node was not done due to tuberculosis history. Flow cytometry on the bone marrow showed an inverted CD4:CD8 ratio. H&E sections of the lymph node revealed a polymorphic lymphoid infiltrate with prominent Reed Sternberg-like cells. Immunohistochemical staining showed CD30-positive and CD45-negative large cells. T-cell and B-cell gene rearrangements were performed. Initially, B-cell gene rearrangements were positive, while T-gamma was negative. Further testing by IHC and morphological evaluation revealed two distinct cell populations, one with CD3, CD5, and CD7 positivity with partial weak positivity for PD1, CD43, and CD8 and the other consisting of B-cells expressing CD30, EBV, MUM1, and partial expression of BCL6 rare CD79a, and partial weak Pax5. Outside molecular testing showed positive T-cell gene rearrangements. The diagnosis of Composite EBV+ Peripheral T Cell Lymphoma, not otherwise specified, with cytotoxic profile along with EBV driven LPD was made. Bone marrow studies confirmed involvement by the same lymphoma. Results (if a Case Study enter NA) NA Conclusion Identifying EBV-positive Reed Sternberg-like cells in both EBV LPD and PTCL-NOS in a composite lymphoma can be challenging. In the absence of flow cytometry, a composite lymphoma can potentially be misdiagnosed, leading to under-treatment. Repeat testing can be helpful in case of any doubt. Although EBV-positive PTCL with cytotoxic profile and EBV-positive LPD has been reported, the combination of these two lymphomas together is exceedingly rare.