Performance of a multigene genomic classifier and clinical parameters in predicting malignancy in a Southeast Asian cohort of patients with cytologically indeterminate thyroid nodules.

BACKGROUND: Most thyroid nodules are benign. It is important to determine the likelihood of malignancy in such nodules to avoid unnecessary surgery. The primary objective of this study was to characterize the genetic landscape and the performance of a multigene genomic classifier in fine-needle aspiration (FNA) biopsies of cytologically indeterminate thyroid nodules in a Southeast Asian cohort. The secondary objective was to assess the predictive contribution of clinical characteristics to thyroid malignancy. METHODS: This prospective, multicenter, blinded study included 132 patients with 134 nodules. Molecular testing (MT) with ThyroSeq v3 was performed on clinical or ex-vivo FNA samples. Centralized pathology review also was performed. RESULTS: Of 134 nodules, consisting of 61% Bethesda category III, 20% category IV, and 19% category V cytology, and 56% were histologically malignant. ThyroSeq yielded negative results in 37.3% of all FNA samples and in 42% of Bethesda category III-IV cytology nodules. Most positive samples had RAS-like (41.7%), followed by BRAF-like (22.6%), and high-risk (17.9%) alterations. Compared with North American patients, the authors observed a higher proportion of RAS-like mutations, specifically NRAS, in Bethesda categories III and IV and more BRAF-like mutations in Bethesda category III. The test had sensitivity, specificity, negative predictive value, and positive predictive value of 89.6%, 73.7%, 84.0%, and 82.1%, respectively. The risk of malignancy was predicted by positive MT and high-suspicion ultrasound characteristics according to American Thyroid Association criteria. CONCLUSIONS: Even in the current Southeast Asian cohort with nodules that had a high pretest cancer probability, MT could lead to potential avoidance of diagnostic surgery in 42% of patients with Bethesda category III-IV nodules. MT positivity was a stronger predictor of malignancy than clinical parameters.

Noninvasive follicular thyroid neoplasm with papillary-like nuclear features and the risk of malignancy in thyroid cytology: Data from Singapore.

INTRODUCTION: The impact of noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) on the risk of malignancy (ROM) in fine-needle aspiration cytology (FNAC) per The Bethesda System for Reporting Thyroid Cytopathology has not been well reported in Singapore. METHODS: We retrospectively identified 821 thyroid nodules with preoperative FNAC from 788 patients out of 1,279 consecutive thyroidectomies performed between January 2010 and August 2016 in a tertiary general hospital in Singapore. Possible cases of NIFTP were reviewed for reclassification and the impact of NIFTP on ROM was analysed. RESULTS: The incidence of NIFTP was 1.2% (10 out of 821). If NIFTP is considered benign, ROM in Bethesda I through VI were 8.6%, 3.5%, 26.3%, 20.0%, 87.7%, 97.0% versus 8.6%, 4.2%, 28.1%, 26.7%, 89.2% and 100% if NIFTP is considered malignant. Eight patients with NIFTP had follow-up of 15 to 110 months. One had possible rib metastasis as evidenced by I131 uptake but remained free of structural or biochemical disease during a follow-up period of 110 months. None had lymph node metastasis at presentation, nor locoregional or distant recurrence. CONCLUSION: Classifying NIFTP as benign decreased ROM in Bethesda II through VI, but the benignity of NIFTP requires more prospective studies to ascertain. The impact of NIFTP on ROM in our institution also appears to be lower than that reported in the Western studies.

Follicular dendritic cell sarcoma: Rare presentation of incidental large hepatic mass.

Follicular dendritic cell sarcoma (FDCS) is a rare tumor, and it is even rarer for FDCS, to affect liver. FDCS is recognized as a distinct entity by the World Health Organization (WHO). Diagnosis is usually post resection and based on typical immunohistochemical stains. Resection with histologic negative margins is proposed, as a mainstay of therapy. We report a 63-year-old woman with large FDCS of the liver, managed with right hemihepatectomy. She remains disease-free at 48 months.

Fine needle aspiration cytology of epithelioid angiosarcoma: a case report.

BACKGROUND: Malignant vascular tumors are rare. Few studies have described cytomorphologic features of hemangioendothelioma and angiosarcoma on fine needle aspiration cytology (FNAC). Malignant vascular tumor with epithelioid morphology can create diagnostic difficulty, as the cytology may simulate that in other nonvascular malignant tumors. We describe epithelioid angiosarcoma, diagnosed on FNAC, in which a differential diagnosis of histiocytosis and inflammatory granulation tissue was considered. CASE: A 20-year-old man presented with forehead and scalp swellings. The forehead lesion was radiologiocally associated with a lytic lesion in the bone. FNA resulted in high cellular yield, and smears revealed prominent vascular pattern with endothelial cell atypia and histiocytoid/epithelioid neoplastic cells, occasional mitotic figures and a few cells displaying nuclear grooving. Smear background showed a significant number of neutrophils. Epithelioid hemangioendothelioma/angiosarcoma, histiocytosis and inflammatory granulation tissue were considered. A cytologic diagnosis of epithelioid angiosarcoma/epithelioid hemangioendothelioma was suggested and confirmed on histopathologic and immunohistochemical examination. CONCLUSION: Cellular aspirates from malignant epithelioid endothelial tumors involving bone may be cytologically mistaken for histiocytosis and, rarely, inflammatory granulation tissue. However, prominent vascular pattern with striking endothelial cell atypia, presence of mitotic figures and careful search for presence of endothelial differentiation are helpful in accurate cytologic diagnosis.

Fine needle aspiration cytologic diagnosis of erythema nodosum leprosum: a case report.

BACKGROUND: Erythema nodosum leprosum (ENL), the type 2 lepra reaction occurring in lepromatous or borderline lepromatous leprosy, presents clinically with acute manifestations that compel the patient to seek medical attention. Recognition and timely management of these patients is critical in order to avoid permanent disability. Fine needle aspiration cytology (FNAC) is a simple, effective tool that aids in correct diagnosis and management of ENL. CASE: A 30-year-old woman presented with history of fever, reddening of the face, and multiple raised, reddish, painful swellings of the bilateral forearms and legs for 7 days. One year previously, she was diagnosed and treated for lepromatous leprosy with type 2 reaction. After a thorough clinical examination a diagnosis of ENL was made. FNA smears from the forearm swellings showed pus-like material with intact and degenerated polymorphonuclear leukocytes and many foamy macrophages with strong granular acid-fast bacillus (AFB) positivity. A cytologic diagnosis of ENL was given, which was confirmed on histopathologic examination of skin biopsy. CONCLUSION: Cytologic features such as a large number of intact and degenerated neutrophils with foamy macrophages and strong granular AFB positivity, in an appropriate clinical background, allows a confident diagnosis of ENL.

Hemangiopericytoma of the thoracic spine: a case report.

Hemangiopericytoma (HPC) has been described to be aggressive and potentially a malignant tumour. We report a rare case of a 63-year-old Chinese male who presented with primary intradural extramedullary HPC of the thoracic spine. The main presenting complaint was gradual progression of back pain, associated with paraparesis and sensory deficit of lower limbs. He had MRI thoracolumbar with contrast which showed T9 lesion compressing on spinal cord and oedema, he was then operated upon and histopathology report confirmed a thoracic spine HPC. A T8/9 laminectomy and excision of intradural extramedullary lesion was performed, tumour section was sent for frozen section study, and more tissue was sent for paraffin studies and additional immunohistochemical staining. Surgical resection is most commonly performed, radiotherapy remains debatable. In this report, we discussed another rare case of primary spinal HPC to be added into the literature.