The Utility of Ancillary Techniques in the Cyto-Diagnosis of Malignant Scalp Lesions

BACKGROUND: Fine needle aspiration cytology (FNAC) is rapid, inexpensive, and easy technique to establish the diagnosis of scalp lesions. The use of ancillary techniques such as immunocytochemistry (ICC), immunohistochemistry (IHC), and flow cytometry on aspiration material aids in accurate diagnosis which is additionally beneficial for management and prognosis. AIMS: The objective of this prospective case series was to evaluate the utility of ancillary techniques in the accurate cyto-diagnosis of malignant scalp lesions. MATERIALS AND METHODS: This study was a prospective case series that included 64 cases of scalp lesions in which FNAC had been performed for diagnosis. The lesions were categorized as Non-diagnostic/Inadequate, Inflammatory, Benign and Malignant. In all the cases that were categorized as malignant additional material was collected for ancillary testing that included ICC, cell block preparation followed by IHC and flow cytometry. RESULTS: Non-diagnostic/inadequate aspirates were 17.19% (n = 11/64), 25% (n = 16/64) aspirates were inflammatory, 35.93% (n = 23/64) aspirates were benign and 21.87% (n = 14/64) aspirates were categorized as malignant. With the aid of ancillary techniques, 57.14% malignant scalp aspirates were accurately categorized as epithelial origin. Lesions of bone and soft tissue constituted 28.57% (n = 4/14) of cases and lesions of hematolymphoid origin constituted 14.29% (n = 2/14) of all cases. CONCLUSION: This is a novel study where accurate categorization of malignant scalp tumors has been done with the use of ancillary techniques. This is useful as it may help in defining the tumor type, may aid in patient management. The material obtained can also be triaged for molecular testing.