Flow cytometry used to identify histiocytic sarcoma: A case report

Diagnostic utility of flow cytometry in identifying histiocytic sarcoma-A case report

Histiocytic sarcoma (HS) is a malignant neoplasm of hematopoietic origin. It is an exceedingly rare and aggressive malignancy commonly seen in adults. Diagnosis is difficult owing to lack of specific clinical manifestations with the absence of precursor lesions or causative agents. Hence, it primarily relies on histopathological morphology combined with immunohistochemistry, which is time-consuming, hence resulting in delayed treatment. However, diagnostic utility of flow cytometry is not well established in this. We report a case of a 45-year-old man who presented with right axillary lymphadenopathy for 1 month. FNAC was performed on the axillary lymph node, which showed large, atypical lymphoid/histiocyte-like cells. On flow cytometry, these cells were CD64+, CD11c+, and CD45+ suggesting histiocytic sarcoma. Similar morphology was seen on incisional biopsy. On immunohistochemistry, the cells were negative for B and T cell markers, PAX5, EMA, CK, ALK, and CD1a and expressed CD68, S100, and CD11c. A diagnosis of histiocytic sarcoma was made. Hence, flow cytometry can be a highly effective and powerful tool for the early detection of HS and can help in prompt treatment, given its aggressive clinical course and low survival interval.

Utility of Flow Cytometry in Diagnosing Hematologic Malignancy in Tonsillar Tissue

OBJECTIVE

Tonsil surgical biopsy or excision is a very common procedure. However, there exist no consensus guidelines for the pathologic handling of tonsil specimens; gross and/or microscopic evaluation may be used. Diagnosis of tonsillar hematologic malignancy requires histology, immunohistochemistry and/or flow cytometry. Data regarding the utility of flow cytometry in tonsillar tissues are limited. We assessed our experience with flow cytometry for tonsil diagnosis with regard to accuracy and use patterns at a tertiary academic medical center.

METHODS

We retrospectively analyzed all surgically biopsied or excised tonsil specimens that underwent flow cytometry evaluation from August 2011 to March 2014. Patient clinical information, intraoperative frozen section, histology, immunohistochemistry, and flow cytometry diagnoses were recorded.

RESULTS

The study included 154 tonsil specimens from 89 females and 65 males. Patients averaged 27.4 years old (range 2-87 years); 73 were pediatric. Both histology and flow cytometry were benign for 148 patients (96.1%). Hematolymphoid malignancy was diagnosed in 6 adults by histology/immunohistochemistry: diffuse large B-cell lymphoma (2), small B-cell lymphoma (2), concomitant follicular lymphoma and histiocytic sarcoma (1), and extraosseous plasmacytoma (1). Flow cytometry identified abnormal populations in 5 of 6 cases, and detected clonal populations in 2 reactive follicular hyperplasia cases.

CONCLUSION

Tonsillar hematolymphoid malignancy is uncommon, and flow cytometry was less accurate than histology/immunohistochemistry for its diagnosis. Despite the rarity of tonsillar lymphoma in children, nearly half of study patients were pediatric. Intraoperative frozen section diagnosis showed excellent sensitivity for malignancy, and could be used to effectively triage cases for flow cytometry evaluation.

Primary histiocytic sarcoma of the uterine cervix: an extremely rare entity

OBJECTIVE

Histiocytic sarcoma (HS) is an extraordinary rare tumor and it has an offensive clinical course. HS of the uterine cervix is a far uncommon tumor with just a few cases described so far. Here we presented a case of primary HS of the uterine cervix in a 62-year-old female initially misdiagnosed as large cell non-keratinizing squamous cell carcinoma. To the best of our knowledge, this is the first reported case of HS of the uterine cervix from Iran.

CASE REPORT

The patient presented with post-menopausal vaginal bleeding. Further evaluations revealed the presence of a relatively large cervical mass that was sampled. Under the preliminary diagnosis of large cell non-keratinizing squamous cell carcinoma, the patient underwent radical surgery. Postoperative pathological examination confirmed the diagnosis of HS of the uterine cervix. The patient received chemotherapy.

CONCLUSION

Clinical presentations of HS of the uterine cervix are very similar to more common cervical tumors; as a result its diagnosis relies on immunohistochemical methods. A correct diagnose could lead to the proper and timely treatment.