19 June 2024 - Case of the Month #539
All cases are archived on our website. To view them sorted by case number, diagnosis or category, visit our main Case of the Month page. To subscribe or unsubscribe to Case of the Month or our other email lists, click here.
Thanks to Dr. Kristen Liu and Dr. Julie Jorns, Medical College of Wisconsin, Milwaukee, Wisconsin, USA for contributing this case and discussion and to Dr. Kristen Muller, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, USA for reviewing the discussion.
Case of the Month #539
Clinical history:
A postmenopausal woman with invasive mucinous carcinoma of the breast underwent segmental mastectomy and sentinel lymph node excision. These images are from the sentinel lymph node excision.
Microscopic images:
What is your diagnosis?
Diagnosis: One lymph node with a benign epidermal inclusion cyst and biopsy site changes, negative for carcinoma
Test question (answer at the end):
A patient with breast cancer undergoes sentinel lymph node excision. What is the next best step based on the histologic findings in the sentinel lymph node shown in the last 2 images above?
Discussion:
Within the lymph node, there is a round, cystic cavity with a lining consisting of giant cells and epithelioid histiocytes. No microorganisms or necrosis are observed. Clinical history is notable for a previous biopsy of the lymph node with benign pathology. As a result, the changes seen are compatible with a foreign body reaction to biopsy material, which in this case was caused by a hygroscopic sonographic clip (Mod Pathol 2018;31:62).
A clipped lymph node may be localized separately or may be identified as a sentinel lymph node when the surgeon injects a radioactive substance, blue dye or magnetic or fluorescent compound to identify the sentinel node(s) (UCLA Health: Sentinel Lymph Node Biopsy [Accessed 30 April 2024]). Radiologists, surgeons and pathologists may use the presence of the cystic cavity to their advantage as it may help to better identify the biopsied lymph node, particularly those that have become smaller following neoadjuvant chemotherapy (Cancers (Basel) 2023;15:2130).
A foreign body reaction is an inflammatory response (often granulomatous), to an exogenous or endogenous substance that the immune system deems foreign. It is important to correlate clinically as the differential diagnosis of granulomatous inflammation can also include infectious (e.g., tuberculosis) and rheumatologic (e.g., sarcoidosis) causes (e.g., chronic granulomatous lymphadenitis).
Adjacent to the biopsy site changes is a smaller benign epidermal inclusion cyst, likely the etiology of the abnormal imaging finding identified in work up of the patient’s breast cancer. The cyst wall is lined by squamous epithelium, including a granular layer and keratin contents. Although uncommon, benign epidermal inclusion cysts have been reported in axillary lymph nodes and are most often found incidentally in the work up for breast abnormalities (Am J Surg Pathol 2011;35:1123).
Test question answer:
C. Perform chart review to confirm prior biopsy. Based on the histologic findings of the lymph node with numerous giant cells surrounding a cystic cavity, a foreign body reaction is suspected. Review of the clinical history should confirm a previous biopsy of the lymph node. In this case there was a recent biopsy with benign pathology. Answers A and B are incorrect because there is no necrotizing granulomatous inflammation suggestive of infection, nor is there any carcinoma present. Answer D is incorrect because the finding of a prior biopsy site does not necessitate additional lymph node sampling.
All cases are archived on our website. To view them sorted by case number, diagnosis or category, visit our main Case of the Month page. To subscribe or unsubscribe to Case of the Month or our other email lists, click here.
Thanks to Dr. Kristen Liu and Dr. Julie Jorns, Medical College of Wisconsin, Milwaukee, Wisconsin, USA for contributing this case and discussion and to Dr. Kristen Muller, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, USA for reviewing the discussion.
Website news:
(1) New Appointments: Dr. Mark Giffen was recently appointed to our Board of Reviewers for Autopsy & Forensic Pathology. Dr. Barina Aqil was appointed to our Board of Reviewers for Hematopathology.
(2) Our cancer precursor project is intended to better understand how cancer arises by compiling a regularly updated spreadsheet of all distinct human cancers (now 1,229) and their precursors (now 171). This essay describes precursors associated with bone and soft tissue malignancies.
(3) We are calling all EU pathologists to sign up for our Worldwide Directory of Pathologists. Our staff will use your information to create a free profile that you can edit or inactivate at any time. This Directory gives each pathologist a free webpage for life + 5 years and helps create a stronger worldwide community of pathologists.
Visit and follow our Blog to see recent updates to the website.
(1) New Appointments: Dr. Mark Giffen was recently appointed to our Board of Reviewers for Autopsy & Forensic Pathology. Dr. Barina Aqil was appointed to our Board of Reviewers for Hematopathology.
(2) Our cancer precursor project is intended to better understand how cancer arises by compiling a regularly updated spreadsheet of all distinct human cancers (now 1,229) and their precursors (now 171). This essay describes precursors associated with bone and soft tissue malignancies.
(3) We are calling all EU pathologists to sign up for our Worldwide Directory of Pathologists. Our staff will use your information to create a free profile that you can edit or inactivate at any time. This Directory gives each pathologist a free webpage for life + 5 years and helps create a stronger worldwide community of pathologists.
Visit and follow our Blog to see recent updates to the website.
Case of the Month #539
Clinical history:
A postmenopausal woman with invasive mucinous carcinoma of the breast underwent segmental mastectomy and sentinel lymph node excision. These images are from the sentinel lymph node excision.
Microscopic images:
What is your diagnosis?
Click here for diagnosis, test question and discussion:
Diagnosis: One lymph node with a benign epidermal inclusion cyst and biopsy site changes, negative for carcinoma
Test question (answer at the end):
A patient with breast cancer undergoes sentinel lymph node excision. What is the next best step based on the histologic findings in the sentinel lymph node shown in the last 2 images above?
- Order breast cancer biomarkers (ER, PR, HER2)
- Order infectious organism stains (AFB, GMS, Gram)
- Perform chart review to confirm prior biopsy
- Recommend biopsy of additional lymph nodes
Discussion:
Within the lymph node, there is a round, cystic cavity with a lining consisting of giant cells and epithelioid histiocytes. No microorganisms or necrosis are observed. Clinical history is notable for a previous biopsy of the lymph node with benign pathology. As a result, the changes seen are compatible with a foreign body reaction to biopsy material, which in this case was caused by a hygroscopic sonographic clip (Mod Pathol 2018;31:62).
A clipped lymph node may be localized separately or may be identified as a sentinel lymph node when the surgeon injects a radioactive substance, blue dye or magnetic or fluorescent compound to identify the sentinel node(s) (UCLA Health: Sentinel Lymph Node Biopsy [Accessed 30 April 2024]). Radiologists, surgeons and pathologists may use the presence of the cystic cavity to their advantage as it may help to better identify the biopsied lymph node, particularly those that have become smaller following neoadjuvant chemotherapy (Cancers (Basel) 2023;15:2130).
A foreign body reaction is an inflammatory response (often granulomatous), to an exogenous or endogenous substance that the immune system deems foreign. It is important to correlate clinically as the differential diagnosis of granulomatous inflammation can also include infectious (e.g., tuberculosis) and rheumatologic (e.g., sarcoidosis) causes (e.g., chronic granulomatous lymphadenitis).
Adjacent to the biopsy site changes is a smaller benign epidermal inclusion cyst, likely the etiology of the abnormal imaging finding identified in work up of the patient’s breast cancer. The cyst wall is lined by squamous epithelium, including a granular layer and keratin contents. Although uncommon, benign epidermal inclusion cysts have been reported in axillary lymph nodes and are most often found incidentally in the work up for breast abnormalities (Am J Surg Pathol 2011;35:1123).
Test question answer:
C. Perform chart review to confirm prior biopsy. Based on the histologic findings of the lymph node with numerous giant cells surrounding a cystic cavity, a foreign body reaction is suspected. Review of the clinical history should confirm a previous biopsy of the lymph node. In this case there was a recent biopsy with benign pathology. Answers A and B are incorrect because there is no necrotizing granulomatous inflammation suggestive of infection, nor is there any carcinoma present. Answer D is incorrect because the finding of a prior biopsy site does not necessitate additional lymph node sampling.
