Jae Yeon Seok

Human Cutaneous Protothecosis: Report of a Case and Literature Review

The Prototheca species is achlorophyllic algae and rarely causes human infection. Human protothecosis presents clinically as a cutaneous infection, olecranon bursitis, and disseminated systemic disease. We report a case of human cutaneous protothecosis involving the left wrist. A 68-year-old man presented with an ill-defined erythematous lesion with crust at the dorsal aspect of his left wrist. A punch biopsy was performed to reveal the histologic features of granulomatous inflammation with necrosis at the upper dermis, containing Prototheca organisms, of which, the characteristic features were highlighted by special staining. Through a molecular study, the Prototheca zopfii species was identified.

Pediatric intracerebral histiocytic sarcoma with rhabdoid features: Case report and literature review

A 16‐year‐old boy presented with marked weight loss, weakness of the left extremities and dizziness of 2 months duration and vomiting for 2 days. Brain MRI showed an approximately 6.5 × 5.3 cm‐sized huge heterogeneous enhancing mass located in the corpus callosum, extending into the lateral ventricle. Open biopsy showed that the lesion consisted of lymphoplasmacytes and plump histiocytes with rhabdoid morphology, which were stained with S‐100 protein, CD68 (KP1) and negative for CD1a. Histiocytic tumor was initially diagnosed. Chemotherapy using methotrexate, 6‐mercaptopurine, vinblastine, interferon‐alpha and dexamethasone was performed. After 5 months, partial removal was done. Microscopically, plump and bizarre tumor cells as well as rhabdoid features were found. Occasional spindle cells and necrosis were also found. These cells were positive for CD163, CD68, lysozyme, CD4, INI‐1 and BRG1. BRAF V600E mutation was detected. The lesion was finally diagnosed as histiocytic sarcoma. Radiotherapy (6000 cGy in 30 fractions) was done. Both cerebral and extracerebral histiocytic sarcomas have long been diagnosed by unclarified criteria; its rarity as well as previously unclarified criteria can easily lead to a misinterpretation. Histiocytic sarcoma of the CNS is exceptionally rare in children, associated with an exceptionally poor prognosis. To date, only seven cases of pediatric cerebral histiocytic sarcomas have been reported. The present case is the first pediatric case showing BRAF V600E‐mutated intracerebral histiocytic sarcoma.

Thyroid Fine-Needle Aspiration Cytology Practice in Korea

We reviewed the current status of thyroid fine-needle aspiration cytology (FNAC) in Korea. Thyroid aspiration biopsy was first introduced in Korea in 1977. Currently, radiologists aspirate the thyroid nodule under the guidance of ultrasonography, and cytologic interpretation is only legally approved when a cytopathologist makes the diagnosis. In 2008, eight thyroid-related societies came together to form the Korean Thyroid Association. The Korean Society for Cytopathology and the endocrine pathology study group of the Korean Society for Pathologists have been updating the cytologic diagnostic guidelines. The Bethesda System for Reporting Thyroid Cytopathology was first introduced in 2009, and has been used by up to 94% of institutions by 2016. The average diagnosis rates are as follows for each category: I (12.4%), II (57.9%), III (10.4%), IV (2.9%), V (3.7%), and VI (12.7%). The malignancy rates in surgical cases are as follows for each category: I (28.7%), II (27.8%), III (50.6%), IV (52.3%), V (90.7%), and VI (100.0%). Liquid-based cytology has been used since 2010, and it was utilized by 68% of institutions in 2016. The categorization of thyroid lesions into “atypia of undetermined significance” or “follicular lesion of undetermined significance” is necessary to draw consensus in our society. Immunocytochemistry for galectin-3 and BRAF is used. Additionally, a molecular test for BRAF in thyroid FNACs is actively used. Core biopsies were performed in only 44% of institutions. Even the institutions that perform core biopsies only perform them for less than 3% of all FNACs. However, only 5% of institutions performed core biopsies up to three times more than FNAC.

Bilateral Stafne Bone Cavity in the Anterior Mandible with Heterotopic Salivary Gland Tissue: A Case Report

Stafne bone cavity is a well demarcated defect of the mandible, usually asymptomatic and located in the posterior portion of the bone.1 Most cases have been reported in male patients between the age of 50 and 70 years.2 This lesion has been labeled with various terms, including ectopic salivary gland, idiopathic defect, mandibular salivary gland inclusion, Stafne bone cavity and cyst.2 The cavities are often filled with normal salivary gland tissue, but occasional cases showed cavity contents that included skeletal muscle, fibrous connective tissue and adipose tissue.1,2 Bilateral Stafne bone cavity of the anterior mandible is extremely rare and only seven such cases have been reported previously.2 Herein, we report a case of bilateral Stafne bone cavity of the anterior mandible.

Rare Case of Anal Canal Signet Ring Cell Carcinoma Associated with Perianal and Vulvar Pagetoid Spread

A 61-year-old woman was referred to surgery for incidentally found colonic polyps during a health examination. Physical examination revealed widespread eczematous skin lesion without pruritus in the perianal and vulvar area. Abdominopelvic computed tomography showed an approximately 4-cm-sized, soft tissue lesion in the right perianal area. Inguinal lymph node dissection and Mils’ operation extended to perianal and perivulvar skin was performed. Histologically, the anal canal lesion was composed of mucin-containing signet ring cells, which were similar to those found in Pagetoid skin lesions. It was diagnosed as an anal canal signet ring cell carcinoma (SRCC) with perianal and vulvar Pagetoid spread and bilateral inguinal lymph node metastasis. Anal canal SRCC is rare, and the current case is the third reported case in the English literature. Seven additional cases were retrieved from the world literature. Here, we describe this rare case of anal canal SRCC with perianal Pagetoid spread and provide a literature review.

Papillary Cystadenoma of the Fallopian Tube Not Associated with von Hippel-Lindau Disease: A Case Report

Papillary cystadenoma (PC) is an epithelial tumor believed to be of mesonephric origin[1] that is found rarely in the female genital tract. Since the original report by Gersell and King in 1988[2], only 14 cases have been reported in the English literature[1,3-5]. All of the reported cases occurred in the mesosalpinx or the broad ligament. Most of the tumors (12 out of 14) were associated with von Hippel-Lindau disease (VHL), similar to epididymal tumors[6]. We report a case of PC within the wall of the fallopian tube (rather than in the mesosalpinx or the broad ligament) in a patient with no clinical history of VHL. A comprehensive review of the literature with regard to differential diagnosis and immunohistochemical profile is provided.

Crush Cytology of Microcystic Meningioma with Extensive Sclerosis

Microcystic meningioma is an unusual type of meningioma that has been described under various names including humid, myxomatous, vacuolated, or arachnoid trabecular cell meningioma.1 Histologically, microcystic meningiomas are characterized by numerous cystic spaces filled with edematous fluid and intermixed meningothelial cells of stellate or spider shape. Cytological descriptions of microcystic meningioma have been limited.2,3

Improvement of diagnostic performance of pathologists by reducing the number of pathologists responsible for thyroid fine needle aspiration cytology: An institutional experience

Various efforts have been made to improve the diagnostic accuracy of thyroid fine needle aspiration (FNA) cytology. We changed the diagnostic system by reducing the number of pathologists responsible for the thyroid FNA cytology in the routine work, and analyzed the effect on the pathologists diagnostic performance.

Nuclear features of papillary thyroid carcinoma: Comparison of Core needle biopsy and thyroidectomy specimens

BACKGROUND Core needle biopsy (CNB) has been used as an alternative or a complementary method for diagnosis of thyroid nodules. However, morphological analysis of the nuclear features of papillary thyroid carcinoma (PTC) cells obtained via CNB remains unclear. Hence, we examined the differences between the PTC nuclear features in CNB and thyroidectomy specimens. METHODS Ten PTC patients, who underwent both CNB and thyroidectomy, were selected. Microscopic photographs of three representative areas of the PTC and adjacent parenchyma were taken. Ten cells per photograph were chosen, and 1200 cells were evaluated (300 PTC and 300 follicular cells in the CNB and thyroidectomy specimens, respectively). The area, circumference, major axis, and minor axis were measured using an image analyzer. Detailed nuclear features (size and shape, membrane irregularity, chromatin characteristics) were scored using a 3-point scale. RESULTS The mean nuclear area, circumference, major axis, and minor axis of PTC cells in the CNB specimen were 1.76, 1.34, 1.34, and 1.29 times larger than those of the follicular cells (p<0.001); similar results were seen in the thyroidectomy specimens (2.04, 1.41, 1.37, and 1.37: p<0.001). Comparative analysis revealed that these parameters were significantly smaller in the CNB specimens than those in the thyroidectomy specimens (p<0.001). Nuclear grades were also lower in the former owing to poor chromatin characteristics (clearing and margination) (p<0.01). CONCLUSION Considering that the PTC nuclei in CNB specimens are smaller with fewer irregularities and less clear than those in thyroidectomy specimens, we need to emphasize caution when using CNB specimens for diagnosis.

Morphologic Analysis of Cytomegalovirus Infected Cells in Bronchial Washing Cytology: Comparison of Liquid-Based Preparation and Conventional Smear

Background: The cytopathic effects of cytomegalovirus (CMV) infection have been well described since the virus was first reported; however, the morphology of CMV infection has not been clearly studied. We examined the difference in detailed cytologic findings in bronchial washing cytology between liquid-based and conventionally prepared smears. Methods: Bronchial washing cytology was processed using either the conventional preparation (CP) or liquid-based preparation (LBP). Sixty-nine cells with typical cytopathic effects of CMV infection were detected on CP slides and 18 cells on LBP slides. Using the image analyzer, area, circumference, major axis, and minor axis of the cytoplasm, nucleus, and intranuclear inclusion were measured in singly scattered CMV-infected cells, and histiocytes were used as a control. Results: The mean cytoplasmic area of CMV-infected cells was 1.47 times larger than that of histiocytes in CP and 2.92 times larger in LBP (p<.05). The mean nuclear area of CMV-infected cells was 2.61 times larger than that of histiocytes in CP and 4.25 times larger in LBP (p<.05). The nucleus to cytoplasm ratio and intranuclear inclusion to cytoplasm ratio of the mean area, circumference, major axis, and minor axis in CP were larger than those in LBP (p<.05). Conclusions: The sizes of cytoplasm, nucleus, and intranuclear inclusion were larger in LBP than in CP, indicating that CMV-infected cells are easily detectable in LBP. However, the nucleus-to-cytoplasm ratio was larger in CP, suggesting that differentiation from malignancy or regenerative atypia requires caution in CP.