Cellular schwannoma: report of a case diagnosed intraoperatively with the aid of cytologic imprints

The diagnosis of cellular schwannoma in intraoperative consultation is difficult because of the hypercellularity and deep location, which may lead to errors. The recognition of cytologic features together with the histological appearance are of great importance to make the correct diagnosis. An accurate diagnosis of this variant of schwannoma is important because other spindle cell tumors display differences in treatment and clinical behavior. We report a demonstrative case of cellular schwannoma arising in retroperitoneum of a 52-yr-old woman in which the cytologic imprints were useful to make an accurate diagnosis intraoperatively. Briefly, the differential diagnosis is discussed.     

Radiation-induced changes in the breast: a potential diagnostic pitfall on fine-needle aspiration.

The authors report a case of fine-needle aspiration (FNA) of a breast mass in a 36-year-old woman with previous history of lumpectomy and therapeutic radiation for breast carcinoma. The changes seen were interpreted as recurrent carcinoma, while subsequent biopsy showed only radiation changes. Radiation-induced changes in breast tissue are a potential diagnostic pitfall. The characteristic cytopathologic changes and their differential diagnosis are discussed.     

微囊性/网状神经鞘瘤的临床病理特点

Objective To study the morphologic characteristics, immunophenotype and differential diagnosis of a case of microcystic/reticular schwannoma occurring in cervical spine. Methods The pathologic features and immunophenotypic profile of a case of microcystic/reticular schwannoma were studied. Immunohistochemistry was performed using EnVision two-step method. Results The patient was a 35 -year-old male and presented with a bump over the fifth cervical spine on radiologic check up. Crossly,the bump was gray-white in color, soft, well-circumscribed but non-encapsulated. The tumor measured 3.5 cm ×3.0 cm × 1. 8 cm in size. Histologically, it was composed of two distinctive components. One component resembled the conventional schwannoma but showed focally nuclear pleomorphism, reminiscent of changes in degenerating schwannoma. The other component consisted of epithelial-like cells arranged in a reticular or lacelike pattern, amongst a myxoid matrix. Immunohistochemical study showed that the tumor cells were strongly positive for vimentin, S-100 protein, glial fibrillary acidic protein and neuron-specific enolase, focally positive for CD68, CD10 and Ki-67, and negative for pan-cytokeratin, epithelial membrane antigen, neurofilament, carcinoembryonic antigen, smooth muscle actin, estrogen receptor, progesterone receptor and p53. Conclusions Microcystic/reticular schwannoma is a novel variant of schwannoma,arising mainly in internal viscera but seldom in bone. Awareness of this entity is helpful in distinction from chordoma, other mucoid tumors or sarcomas.     

微囊性/网状神经鞘瘤的临床病理特点

Objective To study the morphologic characteristics, immunophenotype and differential diagnosis of a case of microcystic/reticular schwannoma occurring in cervical spine. Methods The pathologic features and immunophenotypic profile of a case of microcystic/reticular schwannoma were studied. Immunohistochemistry was performed using EnVision two-step method. Results The patient was a 35 -year-old male and presented with a bump over the fifth cervical spine on radiologic check up. Crossly,the bump was gray-white in color, soft, well-circumscribed but non-encapsulated. The tumor measured 3.5 cm ×3.0 cm × 1. 8 cm in size. Histologically, it was composed of two distinctive components. One component resembled the conventional schwannoma but showed focally nuclear pleomorphism, reminiscent of changes in degenerating schwannoma. The other component consisted of epithelial-like cells arranged in a reticular or lacelike pattern, amongst a myxoid matrix. Immunohistochemical study showed that the tumor cells were strongly positive for vimentin, S-100 protein, glial fibrillary acidic protein and neuron-specific enolase, focally positive for CD68, CD10 and Ki-67, and negative for pan-cytokeratin, epithelial membrane antigen, neurofilament, carcinoembryonic antigen, smooth muscle actin, estrogen receptor, progesterone receptor and p53. Conclusions Microcystic/reticular schwannoma is a novel variant of schwannoma,arising mainly in internal viscera but seldom in bone. Awareness of this entity is helpful in distinction from chordoma, other mucoid tumors or sarcomas.     

微囊性/网状神经鞘瘤的临床病理特点

目的 探讨微囊性/网状神经鞘瘤的形态学和免疫表型特点及鉴别诊断.方法 收集1例发生在颈椎的微囊性/网状神经鞘瘤,根据HE切片和免疫组织化学染色观察形态学及免疫表型特点,并复习相关文献.免疫组织化学采用EnVision两步法.结果 患者男,35岁,因颈部不适就诊,影像学检查见颈5椎体破坏,肿块周围有硬化带,考虑良性病变.手术中见椎体破坏,肿瘤无包膜,结节状,质软,大小约3.5 cm×3.0 cm×1.8 cm.镜下观察,肿瘤无明确包膜,结节状分布,细胞学明确呈两种形态,一种类似于普通神经鞘瘤,但局灶细胞显示明显多形性,似神经鞘瘤伴退变,另一区域呈上皮样细胞,呈网状或蕾丝花边样排列,间质伴显著黏液变性.免疫组织化学示两种区域细胞表达一致,强阳性表达波形蛋白、S-100蛋白、胶质纤维酸性蛋白和神经元特异性烯纯化酶,散在表达CD68、CD10和Ki-67,不表达细胞角蛋白、上皮细胞膜抗原、神经微丝、癌胚抗原、平滑肌肌动蛋白、雌孕激素受体和p53.结论 微囊性/网状神经鞘瘤是神经鞘瘤的一种特殊形态学变型,临床罕见,发生在骨内更为罕见,熟悉其组织学特点和免疫表型有助于与脊索瘤和其他黏液性肿瘤或肉瘤鉴别.     

A case of intraductal tubulopapillary neoplasm of pancreas with severe calcification,a potential pitfall in diagnostic imaging

We experienced a case of intraductal tubulopapillary neoplasms (ITPN) of the pancreas with severe calcification, which complicated image diagnosis. A pancreas head tumor was detected in a Japanese female in her 50s. Early enhancement by contrast‐enhanced CT and coarse calcification suggested a neuroendocrine tumor, although the obstruction and dilation of the main pancreatic duct appeared to be an intraductal tumor. An endoscopic ultrasound‐guided fine needle aspiration biopsy specimen revealed adenocarcinoma tissue. Pancreaticoduodenectomy was performed, and the patient has been well without evidence of recurrence for over 10 months. Pathological examination on the resected specimen revealed that the tumor showed papillary and tubulo‐cribriform growth patterns. Together with typical immunohistochemical results, the final diagnosis of ITPN was made. Characteristically, this case showed extensive calcification of both psammoma body‐type and non psammoma body‐type with foamy macrophage aggregation. This is the first report of ITPN with two types of calcification and macrophage. Since calcification might be one of the characteristic histological findings in ITPN as shown in our case, the possibility of ITPN should be also considered when calcification is detected in pancreatic lesions by various imaging modalities.     

Microcystic adenoma of the pancreas (glycogen-rich cystadenoma) with stromal amyloid deposits

AIMS: We report a case of a pancreatic glycogen-rich microcystic serous adenoma with stromal amyloid deposits, focusing on the significance of isolated amyloid deposits in tumours. METHODS AND RESULTS: The architectural pattern was characterized by thin-walled cysts lined by a single layer of flat or cuboidal epithelial cells intensely stained by the PAS-reaction only before diastase digestion, suggesting the presence of glycogen. Tumour stroma was composed of broad fibrocollagenous tissue with lamellar hyalinized areas which were positively stained by Congo red and showed green birefringence and dichroism with polarized light. For amyloid protein characterization, immunohistochemical studies were performed with anti-beta amyloid protein and anti-amyloid precursor pre-A4695. The former antibody diffusely stained tumour stroma, while the latter stained only scattered stroma cells. CONCLUSIONS: This is the first documented case of amyloid deposition in pancreatic serous adenoma. We indicate that the source of amyloid is an APP-like precursor secreted by stromal myofibroblasts.     

Endophytic malignant transformation within flat adenoma of the colon: A potential diagnostic pitfall

A 74-year-old man was found to have a 1 cm, slightly elevated and flat, red mucosal lesion of the descending colon. An endoscopic biopsy showed a structure characteristic of a tubular adenoma. The surgical specimen revealed an inverted, transmural, solid and cystic lesion. The superficial (intra-mucosal) component of the neoplasm was histologically characteristic of a flat adenoma, showing epithelial dysplasia. However, the contiguous deep component was a well-differentiated adenocarcinoma extending to the serosa and demonstrating the unusual features of a circumscribed lobulated topography and the absence of an inflammatory/desmoplastic stromal reaction. Endophytic malignant transformation within a flat adenoma should be distinguished from conditions of misplaced glandular epithelium such as localized colitis cystica profunda. Complete and full mucosal thickness endoscopic snare removal is indicated in order to assess the degree of epithelial dysplasia and detect endophytic malignant transformation.     

Lobular neoplasia displaying central necrosis: A potential diagnostic pitfall

The distinction between intraepithelial proliferations of ductal and lobular type is often straightforward. However, a small number of cases create diagnostic problems even for experienced pathologists. Among those is the recognized, but not always kept in mind, lobular neoplasia with “comedo-type” necrosis.     

Ovarian signet-ring stromal tumor: a potential diagnostic pitfall

Signet-ring stromal tumor is a rare ovarian neoplasm with only 10 reported cases in the literature. We report an unusual case of ovarian signet-ring stromal tumor in a 69-year-old woman who presented with right adnexal mass and underwent total abdominal hysterectomy and bilateral salpingo-oophorectomy. The diagnosis was based on histological, histochemical, immunohistochemical, and electron microscopy characteristics. The main significance is to differentiate this benign tumor from the highly malignant Krukenberg tumor, and this differential diagnosis is discussed.     

Urothelial carcinoma involving vaginal specimens from patients with neobladder: a potential pitfall in diagnostic cytopathology

Most vaginal neoplasms represent metastasis from the cervix, endometrium, colon and ovary and distinction from a primary lesion does not pose a diagnostic problem. Recently, it has been recognized that women with urothelial carcinoma (UC) who have undergone radical cystectomy with orthotopic neobladder reconstruction are at risk for recurrence in the lower gynecologic tract. Our objective is to describe the cytologic features of cases with confirmed UC in the vagina in this clinical setting. Four vaginal specimens from patients with prior radical cystectomy and orthotopic neobladder reconstruction with histologically confirmed UC were evaluated. The vaginal specimens consisted of Thinprep® and Papanicolaou‐stained slides. Cytomorphologic parameters including cellular arrangement, cell size and shape, cytoplasm, and nuclear features were evaluated and compared with a corresponding surgical biopsy. All four cases were highly cellular with abundant neoplastic cells arranged singly and in loose three‐dimensional clusters with overlapping nuclei. The neoplastic cells were large and polygonal with well‐defined cell borders, high nuclear to cytoplasmic ratio, and granular basophilic cytoplasm. The chromatin was coarse with small nucleoli. Scattered keratinized single cells with atypical hyperchromatic nuclei were observed in each case. In summary, UC involving the vagina can share many morphologic features with primary squamous cell carcinomas at this site, including focal keratinization. Abundant three dimensional clusters of neoplastic cells and a previous history of orthotopic neobladder reconstruction are helpful cytomorphologic and clinical features supporting a diagnosis of UC involving the vagina and may prevent unnecessary work‐up for a new primary lesion. Diagn. Cytopathol. 2011. © 2010 Wiley Periodicals, Inc.