Vaidehi Avadhani

PLAG1: An Immunohistochemical Marker with Limited Utility in Separating Pleomorphic Adenoma from Other Basaloid Salivary Gland Tumors

Objective: Fine-needle aspiration (FNA) diagnosis of salivary gland neoplasms is often challenging. Differentiating between pleomorphic adenomas (PA) and other basaloid neoplasms, especially basal cell adenoma (BCA) and adenoid cystic carcinoma (AdCC), can be difficult in cellular aspirates. PLAG1 (PA gene 1) is a proto-oncogene, which is frequently rearranged in PAs, leading to the aberrant expression of its protein. PLAG1 IHC expression has been reported to be positive in most PAs. The aim of this study was to evaluate the sensitivity and specificity of PLAG1 to differentiate PA from other basaloid neoplasms. Study Design: Immunohistochemical evaluation of PLAG1 was performed on 125 cases (52 FNAs and 73 surgical excisions). Nuclear staining of tumor cells was scored by the intensity and percentage of positive tumor cells. A combined score of >5 was defined as positive. Results and Conclusion: The sensitivity (55%) and specificity (75%) of PLAG1 in diagnosing PA in FNAs is relatively modest thus limiting its diagnostic utility. BCAs and AdCCs showed PLAG1 false positivity, in surgical excision specimens and less so in FNAs. This may be due to limited sampling or tumor heterogeneity. Hence, PLAG1 is a modest marker for PAs in FNAs.

Leiomiosarcoma pulmonar primario: presentación de un caso

Sarcomas are mesenchymal tumors that originate from the stromal elements of the bronchial wall or from interstices of lung parenchyma. Pulmonary sarcomatous neoplasms are a rare and diagnostically challenging group of tumors. They constitute only 0.2%-0.5% of all primary lung malignancies. Primary pulmonary leiomyosarcomas are subdivided into those originating from pulmonary parenchyma, bronchial tree or pulmonary arteries. Here we present a case of 43-year-old African-American female who with chronic cough, fatigue and weight loss. Early detection is the key to the successful management of these patients. The available treatment option is complete resection of tumor. These cases provide an interesting juxtaposition to the management of typical lung cancer.