Large Spindle Cells Research Articles

Histone H3 trimethylation on lysine 27 immunostaining pattern in DICER1-associated tumors.

DICER1-associated tumors are heterogeneous and affect several organs. DICER1-associated primary intracranial sarcoma is associated with histone H3 trimethylation on lysine 27 (H3K27me3) loss in nucleus by immunohistochemistry. We explored the H3K27me3 immunostaining pattern in other DICER1-associated tumors. Twelve tumors from eleven patients with confirmed DICER1 mutations (sporadic and germline) data from a pancancer next-generation sequencing panel, and four tumors of pleuropulmonary blastoma (PPB) were retrieved from our database and stained with anti-H3K27me3 antibody. The H3K27me3 expression in the nucleus showed heterogeneous mosaic loss in neoplastic Sertoli cell components in three of the five cases of moderately to poorly differentiated Sertoli-Leydig cell tumors. Among two tumors of DICER1-associated primary intracranial sarcoma, one showed complete loss of H3K27me3 in all neoplastic cells, whereas the other showed mosaic loss in the sarcomatous spindle cells. One DICER1-associated tumor with epithelial and mesenchymal differentiation, including pulmonary blastoma and PPB, showed mosaic loss of glandular epithelial and mesenchymal components. Four cases of type II PPB and a single case of type III PPB showed a similar mosaic loss of H3K27me3 staining restricted to large spindle cell components. All other components in all tumors-including Leydig cells; the areas of epithelial, cartilaginous, and rhabdomyomatous differentiation; and all cells of the remaining three cases (one papillary thyroid carcinoma and two cases of PPB type I)-demonstrated retained H3K27me3 staining. H3K27me3 expression is not universally lost in DICER1-associated tumors and thus is not predictive of DICER1 mutation status. The mosaic regional loss of H3K27me3 immunostaining is consistent in PPB type II and III, which can be a helpful diagnostic marker for these tumors and suggests a similarity to DICER1-associated intracranial sarcoma.

Abstract #1402832: Doege-Potter Syndrome Due to Solitary Fibrous Tumor of the Kidney

Solitary fibrous tumor (SFT) is a rare mesenchymal tumor which can be benign or malignant. A small subset (<5%) of patients with SFT present with refractory hypoglycemia, known as Doege-Potter syndrome. This is due to increased production of insulin-like growth factor (IGF-2), its precursor pro-IGF-2, and is associated with large tumor size or aggressive clinical behavior. A 77-year-old female was brought to the ER after was found down at home with hypoglycemia down to 20 mg/dL during a wellness check. She had slurred speech and right-sided weakness. MRI of the brain and MRA of head and neck were unremarkable. She was found to have a urinary tract infection which was treated with antibiotics. Due to concern for stroke, aspirin was started. Subsequently she developed hematuria. A CT abdomen and pelvis was performed that revealed a large 17 x 12 x 11 cm heterogenous exophytic mass from the anterior margin of the right kidney. Patient's encephalopathy and focal weakness resolved with glucose administration, but she continued to have recurrent hypoglycemic episodes. A repeat MRI of the brain showed no evidence of metastatic disease and no evidence of CVA. Thyroid, adrenal and liver function tests were within normal range, and insulin and C-peptide levels were grossly suppressed during hypoglycemic episodes. IGF-1 and IGF-2 levels were normal. In the absence of any underlying endocrine pathology or the administration of any hypoglycemic agent, clinically Whipple’s triad was positive (symptoms attributable to hypoglycemia, plasma hypoglycemia at time of symptoms and resolution of symptoms with treatment of hypoglycemia). Tumor induced hypoglycemia was suspected and she underwent right radical nephrectomy. Pathology demonstrated a fully resected large (21 x 11.5 x 11 cm) spindle cell neoplasm, positive for CD34 and STAT6, consistent with solitary fibrous tumor. Post-surgically her hypoglycemia resolved. Our case highlights the importance of early diagnosis and intervention in Doege-Potter syndrome. Hypoglycemia with low levels of serum insulin, C-peptide, and beta-hydroxybutyrate in a healthy-appearing person should prompt evaluation for a tumor with cross-sectional imaging of the chest, abdomen, and pelvis. Although our patient had normal IGF-2 levels, pro-IGF-2 levels were not checked. In SFT the hypoglycemia may be due to elevated IGF-2 or pro-IGF-2 levels which leads to inappropriate activation of systemic insulin receptors and inhibition of glucose release from the liver leading to fatal hypoglycemia. Tumor induced hypoglycemia should be considered as the primary differential diagnosis when hypoglycemia is without an alternative cause.

A Rare Case of Primary Spindle Cell Synovial Sarcoma of Scalp

Abstract Synovial sarcoma is a variant of soft-tissue sarcoma, but has a very aggressive course. It is very rare overall, constituting only 5%–10% of all soft-tissue sarcomas. Head and neck constitutes 3%–5% of cases. It is more common in males in the 15–40 years age group. Hence, histopathological confirmation is required for diagnosis along with radiological investigations like magnetic resonance imaging. If histopathology/immunohistochemistry also cannot give a definitive diagnosis, chromosomal translocation t(x; 18) (p11.2–q11.2) assay is required as it is present in more than 90% of cases. Rarity of cases leads to the absence of proper treatment guidelines. Here, we are reporting a case of a large primary spindle cell synovial sarcoma of the scalp in a 57-year-old female, developed just over a month, pushing brain parenchyma, describing her treatment by volumetric modulated arc therapy (VMAT) radiotherapy to spare surrounding critical organs, particularly brain and eyes.

LUNG CANCER IS NOT ALWAYS THE ANSWER: EXPLORING THE DIFFERENTIAL DIAGNOSIS OF THORACIC MASSES

LUNG CANCER IS NOT ALWAYS THE ANSWER: EXPLORING THE DIFFERENTIAL DIAGNOSIS OF THORACIC MASSES

AGGRESSIVE ORAL MELANOMAS: REPORT OF TWO CASES INVOLVING HARD PALATE

A 51-year-old woman and a 73-year-old man reported to the hospital presenting extensive dark lesions on the right and left hard palate, respectively. Histopathologic analysis showed fragments of squamous mucosa with large rounded and spindle cell infiltration. Cells presented with a clear cytoplasm, nuclei with granular chromatin, and evident eosinophilic nucleoli. In some foci, there was an abundance of intracytoplasmic brownish pigmentation. Immunohistochemistry reactions presented positive results for MelanA, S-100, HMB45, and SOX-10. The Ki-67 index showed moderate cell proliferation. After the diagnosis of malignant mucosal melanoma, partial maxillectomy was performed in both cases. The male patient underwent postoperative radiotherapy, with no recurrence of the lesion to date. The female patient, however, had cervical metastasis 1 year after surgery. Unilateral lymph node dissection was performed, and the patient is currently undergoing chemotherapy for breast cancer. A 51-year-old woman and a 73-year-old man reported to the hospital presenting extensive dark lesions on the right and left hard palate, respectively. Histopathologic analysis showed fragments of squamous mucosa with large rounded and spindle cell infiltration. Cells presented with a clear cytoplasm, nuclei with granular chromatin, and evident eosinophilic nucleoli. In some foci, there was an abundance of intracytoplasmic brownish pigmentation. Immunohistochemistry reactions presented positive results for MelanA, S-100, HMB45, and SOX-10. The Ki-67 index showed moderate cell proliferation. After the diagnosis of malignant mucosal melanoma, partial maxillectomy was performed in both cases. The male patient underwent postoperative radiotherapy, with no recurrence of the lesion to date. The female patient, however, had cervical metastasis 1 year after surgery. Unilateral lymph node dissection was performed, and the patient is currently undergoing chemotherapy for breast cancer.

Patient Reported Outcomes in Metastatic Spine Disease: Concurrent Validity of PROMIS with the Spine Oncology Study Group Outcome Questionnaire.

Cross-sectional prospective study. To evaluate the Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function (PF), Pain Interference (PI), and Depression domains in comparison to the Spine Oncology Study Group-Outcomes Questionnaire (SOSG-OQ) in patients with metastatic spine disease. While there remains a significant movement toward incorporating patient-reported outcome measures (PROMs) into clinical care, there are few validated PROMs for patients with metastatic spine disease. The SOSG-OQ was designed and validated for metastatic spine tumor patients. However, the use of general symptom-based PROMs, such as PROMIS domains, may reduce both patient and physician burden and improve interdisciplinary care if shown to be concurrently valid. Metastatic spine tumor patients from January 2017 to July 2021 at a single academic medical center were asked to complete PROMIS PF, PI, and Depression domains and the SOSG-OQ. Spearman correlation (p) coefficients were calculated. A total of 103 unique visits, representing 79 patients met our inclusion criteria. A majority were men (59; 57%) and Caucasian (93; 90%), and the average age was 64-years-old (range: 34-87). There were 13 different types of histologies reported, with multiple myeloma, breast cancer, and prostate cancer representing 28 (27%), 26 (25%), and 13 (13%), respectively. Additional cancers included renal cell carcinoma, lung cancer, colon cancer, thyroid cancer, large B-cell lymphoma, nonHodgkin lymphoma, esophageal cancer, plasmacytoma, metastatic paraganglioma, and metastatic spindle cell sarcoma. SOSG-OQ was strongly correlated with PROMIS PI (ρ = 0.78) and PROMIS PF (ρ = 0.71), and moderately correlated with PROMIS Depression (ρ = 0.58). PROMIS PF, PI, and Depression appear to capture similar clinical insight as the SOSG-OQ. Spine surgeons can consider using these PROMIS domains in lieu of the SOSG-OQ in metastatic spine tumor patients.

BROWN TUMOR IN A PATIENT WITH PRIMARY HYPERPARATHYROIDISM: A CASE REPORT OF A LESION WITH AN UNUSUAL BEHAVIOR

A 33-year-old woman presented with a 2-year history of a large swelling on the right side of the mandible accompanied by chin paresthesia. Intra-oral examination revealed a firm enlargement beneath the normal overlying mucosa in the retromolar region. Panoramic radiograph revealed a multilocular lesion extending from the molar region to the ramus (about 15 cm). A round central radiolucent area was also noted beneath the roots of the incisor teeth. Cone beam computed tomography evaluation revealed an aggressive lesion, with rupture of the cortical plates of both sites. Biopsy revealed connective tissue with large spindle cells, with multinucleated giant cells, a large amount of blood vessels, and woven bone with osteoid deposition. Serologic tests showed altered levels of parathyroid hormone (2.377 pg/mL), alkaline phosphatase (753 U/L), and calcium (12.5 mg/dL). Final diagnosis of brown tumor of hyperparathyroidism was made, and the patient was referred to endocrinology treatment and to intralesional corticoid injection.

Clinicopathologic Study of Ewingandrsquo;s Sarcoma in 82 Sudanese Patients Diagnosed at Histo Centre/ Khartoum (2013-2018)

Ewing’s sarcoma is the second most common childhood bone neoplasm, which is considered rare in African population. This is the first study in Sudan. The aim of the study is to demonstrate the clinical and histo-morphological findings of these tumours and to compare the results with similar studies. A retrospective cross-sectional study was done, conducted over 6 years’ period on 82 cases diagnosed as ES/PNET at Histo-Centre located in Khartoum state. Twenty-six of them were found to have CD99 immune-stain and ten cases have PAS special stain, data were collected, H and E, PAS and CD99 stained slides were examined by light microscope. Data analysis showed that the peak incidence of ES/PNET occurs between 5 to <18 years (58.5%) with a Mean age: 16.9 years. It shows obvious male predominance accounting for 64.6% of cases. The majority of cases are intra osseous tumour, with only 11% of cases are extra osseous, the lower limb is the most common site accounting for 54.9% of the cases, followed by the flat bones of the pelvis 13.4% with the vertebra and the skull being the least common sites accounting for 1.2% each. In clinical presentation 74.4% presented with localized swelling, 34% as localized pain, Fever and pathological fractures were the presentation in 2.4% and 3.7% respectively and none of the study population were presented as metastatic disease. Microscopic examinations of the H and E stained slides showed that 57.3% of the cases are ES devoid of neural differentiation while the rest are PNET showing some degree neural differentiation devoid of neural differentiation, among PNET cases, Homer Wright rosette were the most common rosettes in about 70% of cases. Focal areas of atypical features were found in 15.9% of cases with the pleomorphic large cells and spindle cells being the most commonly encountered features. Necrosis is present in 52.4% of cases. PAS was positive in 9 out of the 10 cases. While all the 26 cases with CD99 stained slides were positive, only 61.5% showed diffuse strong membranous positivity. In Conclusion although the demographic features and clinical presentations of ES/PNET in the study population were found to be similar to other global and regional studies finding 82 cases/6 years in single centre makes its rarity among African nations doubtful.

ES04.02 Pathology Overview for Carcinoid and NE Spectrum

ES04.02 Pathology Overview for Carcinoid and NE Spectrum

Generalized crystal-storing histiocytosis with diffuse large B-cell lymphoma and monoclonal gammopathy in a Chinese elderly woman: a case report

BackgroundCrystal-storing histiocytosis (CSH) is a rare lesion characterized by sheets of crystal-laden non-neoplastic histiocytes. CSH shows a prominent association with lymphoproliferative disorders that express monoclonal immunoglobulins, mainly multiple myeloma (MM), lymphoplasmacytic lymphoma (LPL) and monoclonal gammopathy of undetermined significance (MGUS). However, no aggressive B cell lymphoma has been reported to be associated with CSH.Case presentationA 74-year-old Chinese woman presented with multiple subcutaneous masses, abdominal pain, and fever. An IgM kappa type of monoclonal gammopathy (MG) was noted by immunofixation performed on the patient’s serum. Computed tomographic (CT) scan revealed subcutaneous masses on the left upper arm and at the waist and multiple low-density lesions in the spleen. Microscopically, sections of subcutaneous masses revealed sheets of large polygonal and spindle cells with abundant eosinophilic cytoplasm, round to ovoid eccentric nuclei, reticulate chromatin, and median nucleoli. Massive needle-shaped crystals were confined to the cytoplasm. Immunohistochemically, these crystal-containing cells were positive for CD68/PGM1, CD163, IgM, and Igκ. Meanwhile, the splenic tumour was diagnosed as diffuse large B-cell lymphoma (DLBCL), non-germinal-centre B (non-GCB) subtype (Hans algorithm). Immunohistochemistry for IgM was positive in the cytoplasm of some neoplastic cells. Immunoglobulin heavy chain (IgH) gene rearrangement was detected by PCR analysis of the subcutaneous mass and the splenic tumour.ConclusionTo the best of our knowledge, this is the first case of generalized CSH with DLBCL and MG. Although the rarity of CSH and separate locations of CSH and lymphoma led to a diagnostic dilemma, the presence of MG was a clue to appreciate the relation between CSH and DLBCL. This case stressed a full investigation into the underlying lymphoproliferative disorder for integrated diagnosis and correct treatments.

Malignant Triton Tumour: Case report

Malignant triton tumours (MTTs) are a rare subtype of malignant peripheral nerve sheath tumour (MPNST) showing rhabdomyoblastic differentiation, which have no treatment consensus and a poor prognosis. This case report presents case of a 71yrs/ male with swelling in Right Hand over one month. Patient had same swelling 2yrs back which was diagnosed as Peripheral Nerve Sheath Tumour on histopathology following which he underwent surgery followed by radiotherapy. Swelling reappeared at same site after 3 months. FNAC of swelling shows large spindle cells having elongated buckled nuclei, pointed end, with varying nucleus size and coarse nuclear chromatin. Few cells are showing Rabdomyoblastic differentiation.

Kamino bodies.

Hideko Kamino [Figure 1], a world-renowned American dermatopathologist, among her boundless medical contributions, is credited for describing pinkish, round globules with irregular edges, located above the papillary dermis known as Kamino bodies (KBs, also known as eosinophilic globules) in 1979.[1] KBs were originally described in Spitz nevi; however, there are reports of its presence in other lesions, such as Reed nevus, “spitzoid” tumor and malignant melanoma (MM).[2]Figure 1: Dr. Hideko Kamino, world-renowned American dermatopathologistKBs histopathologically are solitary rounded or confluent, amorphous, eosinophilic masses of basement membrane material, found at the dermo-epidermal junction, most commonly at the tips of dermal papillae [Figures 2 and 3], in some Spitz nevi and far less commonly, in other benign and malignant melanocytic proliferations. KBs are hyaline structures that stain positively with periodic acid-Schiff and trichrome and are commonly found in the dermo-epidermal junction [Figure 4]. The eosinophilic nature of these structures is often obscured by melanin pigmentation.[3]Figure 2: Pointed arrow Kamino bodies (H&E)Figure 3: Illustrated Kamino bodiesFigure 4: Kamino bodies (PAS, ×200 and ×1.000)KBs were once believed to have been degenerated basal cells or melanocytes. However, studies have shown that they comprise collagen (type IV and VII), laminin and fibronectin, among other substances. In 1979, Kamino et al. described dull pink globules in the epidermis of 65% of junctional, 75% of the compound and 25% of intradermal types of Spitz nevi (the nevi of large spindle and/or epithelioid cells). These globules were periodic acid–Schiff (PAS)-positive, diastase resistant and positive on trichrome staining. Similar eosinophilic globules were noted in the epidermis in only 2% of malignant melanomas and 0.9% of ordinary melanocytic nevi. The globules in malignant melanomas and ordinary melanocytic nevi were negative with PAS and trichrome staining. Kamino et al. concluded that PAS and trichrome-positive eosinophilic globules in the epidermis can aid in the histological differentiation of Spitz nevus from malignant melanoma.[1234] Clusters of KBs are so much more common in Spitz nevi than in other lesions that they form an important diagnostic clue. However, their presence does not rule out melanoma completely because a rare melanoma contains similar clustered KBs. In H&E sections, KBs show some resemblance to Civatte bodies, as can be found in lichen planus or colloid bodies or a number of eosinophilic hyaline globules [Table 1] in the dermo-epidermal junction, so the following distinguishing features helps one identify true KBs.[1234567]Table 1: Distinguishing features between kamino bodies and colloid bodiesSubsequently, recent research has confirmed the presence of KBs in melanomas, among them Ackerman et al., who considered them to be rare in melanomas, Arbuckle and Weedon, who spotted them in 12% of melanomas, and Peters and Goellner, who claimed to have recognized them in 26% of melanomas. No author, however, even those who thought they had seen KBs in more than a quarter of melanomas, has ever stated that those bodies could be numerous in melanomas.[4] LeBoit reported that with the globules of most dermatopathologists thus “KBs can be large and numerous in Spitz nevus. Although they can occur on rare occasions in melanomas, they are often small and few.”[5] Moreover, in one quote from Arbuckle, one image shown as KBs may have actually been a dyskeratotic cell in the dermo-epidermal junction. Hence, the presence of KBs in MM is uncertain, but they appear to be rare or absent.[67] In sum, there is an inclination among many pathologists, worldwide, to equate many dull pink globules within the epidermis of a melanocytic neoplasm with Spitz nevus. That assumption can lead to serious errors in diagnosis because KBs may be numerous in melanomas. We conclude that KB, pigmented or nonpigmented, is a common histological finding in Spitz nevus and can be a good marker to aid in their differentiation from MM. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest. Acknowledgments Dr. Mohan K. P. Professor, Department of Oral and Maxillofacial Pathology and Microbiology, College of Dental Sciences, Davengere, Karnataka.

Controlateral and mesenteric metastasis of kidney leiomyosarcoma sixteen years after the surgery: A case report

Introduction: Primary renal leiomyosarcoma is an extremely rare malignant tumour. It is more common in females than in males and in the right kidney. The diagnosis is difficult. The prognosis is poor because of frequent metastasis and recurrence. Case Report: A 41-year-old woman who had undergone left radical nephrectomy for a kidney tumour 16 years previously presented to our institution with right flank pain. On examination, the left sided mass was a 20 cm encapsulated firm tumor with necrotic and hemorrhagic foci compressing the residual kidney. Histological examination showed a high cellular proliferation of large spindle cells mixed with necrosis and calcification. Nuclei were irregular, hyperchromatic, 4 mitoses/10hpf were counted. Renal capsule and renal vein were tumor free. Tumors cells were positive for smooth muscle actin (AML), neuron specific enolase (NSE), with negative expression for, anti S100, cytokeratin, Epithelial membrane Antigen (EMA), HMB45 and CD34. Histopathological examination concluded to a low grade leiomyosarcoma without capsular effraction neither lymph node invasion measuring 20x13x10 cm. No postoperative treatment was indicated and the patient was lost to follow up for 16 years. Imaging finding (MRI) revealed a solid heterogenic mass at the lower pole of the right kidney. Besides, three mesenteric masses were noticed. A controlateral and mesenteric metastasis of the left kidney leiomyosarcoma was suspected. In order to confirm the diagnosis, an ultrasound guided biopsy of the right kidney lesion was performed. Histopathological findings concluded to a low grade leiomyosarcoma. The patient did not undergo surgery and was referred to a medical oncology center and chemotherapy is in progress. Conclusion: Leiomyosarcoma of the kidney is a rare aggressive tumour. Only few cases are reported in literature. Clinical features are non-specific making generally a delayed diagnosis. The treatment is based on surgery. The prognosis is still poor.

A Case of Large Breast Spindle Cell Carcinoma Which Resected Pulmonary Metastasis 3 Years after the Primary Surgery

A Case of Large Breast Spindle Cell Carcinoma Which Resected Pulmonary Metastasis 3 Years after the Primary Surgery

HG-18 * A ROLE OF SPINDLE CELLS IN GLIOBLASTOMA GROWTH

BACKGROUND: Bailey and Cushing believed gliomas originated from primitive spongioblasts (1926). The authors have found the spindle cells in the early stage of rat C6 cell cuture, resembling spongioblasts. Additionally, C6 cells implanted into rat brain grew glioblastoma (GBM). In an effort to link cultured C6 cells to molecular biological factors, demonstration of cell markers was attempted in these cells. MATERIALS AND METHODS: C6 cells were cultured in MEN solution and morphological changes were observed for 10 days. Next, cultured C6 cells were treated by temozolomide (TMZ), starting Day 3, and observed for 7 days. C6 cells were also implanted into rat's brain to observe tumor formation. CD133 and CD15 staining was done in cultured cells and TMZ treated cells. RESULTS: Small long cells with single nucleus grew to spindle cells on Day 1 to 2. Spindle cells increased rapidly, forming syncytiums on Day 3 to 4. As syncytiums multiplied, mitotic cells began to appear on Day 5 to 8. By Day 9-10 multiple small round cells were packed in groups, and then typical undifferentiated GBM cell pattern developed. During TMZ treatment, the number of C6 cells remarkably decreased forming necrotic areas, and only large spindle cells survived, resembling spongioblasts, in 4 days after the TMZ started. Implanted C6 cells survived, forming a mass, and contained spindle cells. CD133 and CD15 were used to stain cell membrane as markers on cultured and TMZ-treated cells, and results will be reported both in cultured C6 cells, and implanted tumors. CONCLUSION: The spindle cells of C6 cells played an important role for tumor growth and tumor invasion. Cell marker staining will allow for concluding relationship of spindle cells to stem cells (if stained with markers) or precursors, in comparison with radiated medulloblatoma cells stained with CD133.

Spitz nevus on the sole of the foot presenting with transepidermal elimination.

A 10-year-old Japanese girl presented with a rhomboid-shaped brown macule, 4x3 mm in size, on the sole of the right foot. Dermoscopic examination revealed a number of black dots and globules on the ridges of the skin, marking an area of symmetrical brown pigmentation. On the periphery, a streak-like arrangement of black dots/globules on the brown pigmentation was observed along the ridges, simulating a “starburst” pattern. The lesion was excised and histological examination showed a symmetrical wedge-shaped compound melanocytic lesion that consisted of junctional and intradermal nests of a mixture of large spindle and epithelioid cells. None of the cells were atypical, and maturation of the cells with increasing depth was observed. From these findings, a diagnosis of Spitz nevus was made. Transepidermal elimination of nevus cell nests was observed and there were small groups of degenerated melanin-laden cells in the cornified layer. Masson Fontana stain revealed fine melanin deposits in the nevus cells of the junctional and intradermal nests, as well as heavy melanin deposits in the small groups of degenerated cells in the cornified layer. The distribution of melanin may contribute to a unique dermoscopic finding in this case.

Cytologic features of pigmented atypical meningioma mimicking melanoma on intraoperative crush preparations

Pigmented tumors rarely arise in the meninges, and when they do, these are mainly melanocytomas or melanomas. We describe the cytologic findings of atypical meningioma with intratumoral hemosiderin pigment mistaken for spindle cell melanoma in a 33-year-old male patient during intraoperative consultation. Preoperative radiologic images revealed a cystic meningeal mass with intratumoral hemorrhage. The crush preparation demonstrated cellular smears of syncytial clusters as well as fascicles of large pleomorphic spindle cells with discrete cytoplasmic brown pigment. Detection of cytoplasmic brown pigment and a preponderance of large spindle cells with nuclear pleomorphism led to a diagnosis of spindle cell melanoma on intraoperative cytology. Histopathologic examination displayed high cellularity, nuclear pleomorphism with prominent nucleoli, and foci of spontaneous necrosis. In addition, there were areas showing classic meningotheliomatous meningioma features. Altogether, the histologic findings were consistent with atypical meningioma. The cytoplasmic pigment in the tumor cells was confirmed to be hemosiderin using special stains and immunohistochemistry. To the best of our knowledge, this is the first case report describing cytomorphology of atypical pigmented meningioma. We discuss the differential diagnosis in intraoperative cytology and a possible mechanism related to intratumoral hemosiderin deposition in meningiomas.

混合型大細胞神経内分泌癌と紡錘細胞癌の異時性多発肺癌に対する1手術例

稀な腫瘍である混合型大細胞神経内分泌癌と紡錘細胞癌を含む異時性多発肺癌の1切除例を経験したので報告する．症例は60歳代，男性で，健診の胸部レントゲンで異常陰影を指摘され当院を受診した．CTで左上葉S5に充実性結節，S1＋2, S3にスリガラス陰影を認め，胸腔鏡下左上葉切除術を施行した．病理検査でS5の結節は腺癌成分を含む混合型大細胞神経内分泌癌（T1bN0M0）と診断された．その他の結節は腺癌であった．術後補助化学療法を施行したが，術後1年で右中葉に孤立性の充実性結節が出現した．混合型大細胞神経内分泌癌の転移を疑い，化学療法を行ったが短期間で増大した．発見より8ヵ月後に右中葉切除術を施行した結果，紡錘細胞癌（T2aN0M0）と診断され，異時性多発癌と考えられた．現在再手術後1年経過し無再発生存中である．

Atypical melanocytic lesions of the thigh with spitzoid and dysplastic features: a clinicopathologic study of 29 cases

Melanocytic nevi in certain anatomic locations can display unusual histopathologic features potentially creating diagnostic uncertainty. Benign melanocytic nevi in sites such as acral, genital, and flexural areas may show unusual architecture and cytologic atypia, which can mimic dysplastic nevi and, sometimes, melanoma. Twenty-nine benign melanocytic skin lesions were identified in the thigh of 26 women and 3 men who showed atypical histologic features, including both dysplastic and spitzoid features. All lesions measured less than 1 cm in diameter. Eighteen cases showed features of compound nevi, and 11 were junctional. In all cases, the lesions displayed spitzoid features including large epithelioid and/or spindle cells, some melanocytes with ganglion-like cytomorphology, and focal suprabasilar upward migration. All cases showed dysplastic features. Clinical follow-up was available in 26 patients; no recurrences or metastases were observed. The demographic features and the anatomical sites of these melanocytic nevi appear to be reproducible, and in the assessment of histologically difficult cases, these data are helpful. It is our opinion that the malignant potential of these lesions with hybrid patterns (spitzoid/dysplastic) has yet to be determined, and although we favor these lesions to be benign, longer follow-up may yield a more complete understanding of their biologic potential.

Granular Cell Tumor Originating from Gallbladder

Granular cell tumors are rare benign tumors that arise from Schwann cells. They are especially rare in the gallbladder; indeed, only four cases have been reported in the English-language literature. This paper reports a granular cell tumor in the gallbladder and is the first such report in a Korean woman. She was admitted to the hospital with jaundice and fever and was diagnosed with acute hepatitis A. While hospitalized, a well-demarcated round mass was incidentally found in her gallbladder. The acute hepatitis A improved with conservative care, but the mass did not change in size after 4 months. The tumor was resected with the gallbladder during laparoscopic surgery, and was found to be a granular cell tumor. The tumor was composed of sheets or irregular fascicles of large polygonal or spindle cells with plump eosinophilic granular cytoplasm that was immunohistochemically positive for S-100 and neuron-specific enolase and negative for neurofilament. (Korean J Med 2012;83:624-628) Keywords: Gallbladder; Biliary tract; Granular cell tumor