Ultrasound-guided fine-needle aspiration biopsy of thyroid neoplasms with lipomatous stroma: Report of two cases.

Thyroid tumors with abundant adipose tissue component are rare, reportedly accounting for 0.98-2.8% of all thyroid nodules, and include entities such as thyroid lipoadenoma and thyroid carcinoma with lipomatous stroma (TCLS). They may be encountered on fine-needle aspiration biopsy (FNAB), which is widely used in evaluation of thyroid nodules. However, due to their relative rarity, adipose elements rarely are recognized preoperatively in these tumors. Herein, we report two cases of thyroid tumors with abundant adipose tissue, along with cytologic, histologic, and ultrasonographic features. Although an intermixture of adipose tissue and thyroid follicular cells is the key cytologic feature of thyroid tumors with adipose stroma, other cytologic findings, such as abundant fat droplets or isolated fragments of adipose tissue, also should raise the possibility of a fat-containing tumor, particularly when a biopsy is performed by a cytopathologist under ultrasonographic guidance and adequate radiologic-pathologic correlation. Cytopathologists should be aware that overlooking lesional adipose tissue within a thyroid neoplasm might give the false impression of a non-diagnostic or sparsely cellular FNAB specimen.

Uterine Carcinosarcomas: Clinical, Histopathologic and Immunohistochemical Characteristics.

Carcinosarcomas (malignant mixed Müllerian tumors or MMMT) are rare malignant tumors in the female genital tract composed of both malignant epithelial and malignant mesenchymal components. They comprise <5% of all neoplasms in the gynecologic tract and have an aggressive clinical course. The purpose of this study is to evaluate the immunophenotype and possible histogenesis of carcinosarcomas of the uterus. Sixty-two cases of uterine carcinosarcomas diagnosed between 1995 and 2011 were retrieved from the gynecologic pathology files at Columbia University Medical Center. Representative tissue blocks containing both epithelial and mesenchymal components were selected from each case for histologic and immunohistochemical studies. Clinical data from each case were retrieved. The epithelial component was poorly differentiated adenocarcinoma in the majority (80.7%) of cases; in 17.7%, the carcinoma was moderately differentiated, and in only 1.6% the carcinoma was well differentiated. 53% of the tumors had homologous stromal elements and 47% displayed heterologous stromal elements. Immunohistochemical study revealed almost equal staining in both epithelial and mesenchymal components of carcinosarcomas for p16 and p53. PAX8 positivity was noted in 73% of epithelial components, but only 13% of stromal components, and PAX8 stromal positivity was never seen in the absence of PAX8 epithelial positivity. Expression of p16, p53, and PAX8 in both malignant components lends support to the monoclonal theory of uterine carcinosarcoma tumorigenesis. The roles of these tumor markers in the diagnosis and pathogenesis of this tumor and associations between clinical characteristics, tumor pathologic features, and prognosis are discussed.

Metastatic tonsillar squamous cell carcinoma masquerading as a pancreatic cystic tumor and diagnosed by EUS-guided FNA.

Metastatic carcinoma to the pancreas is uncommon and head and neck squamous carcinoma metastatic to the pancreas is extremely rare. Metastatic squamous cell carcinoma to the pancreas presents a unique diagnostic challenge: in addition to mimicking the rare primary squamous cell carcinoma of the pancreas based on cytologic, histologic, and immunohistochemical features, it may be mistaken for a cystic neoplasm of the pancreas because of its high predilection for cystic degeneration in metastatic sites. Herein, we report a case of tonsillar squamous cell carcinoma with a cystic pancreatic metastasis diagnosed by ultrasound-guided fine needle aspiration biopsy (EUS-FNA). This represents a third reported case of metastatic squamous cell carcinoma to the pancreas from the head and neck region. Metastatic squamous cell carcinoma should be considered in the differential diagnosis of EUS-FNA during evaluation of pancreatic cystic lesion.

Targeted Next-Generation Sequencing Analysis of a Pendred Syndrome-Associated Thyroid Carcinoma.

Pendred syndrome is an autosomal recessive disorder characterized by hearing loss and goiter and is caused by bi-allelic mutations (homozygous or compound heterozygous) of the PDS (SLC26A4) gene. The incidence of Pendred syndrome is 7.5-10/100,000 in the general population, and it carries a 1 % risk of developing thyroid carcinoma. Herein, we report a case of a patient with Pendred syndrome who developed a follicular variant of papillary thyroid carcinoma (FVPTC)-that is approximately at an odd of 1/1,000,000. Targeted next-generation sequencing with ThyroSeq v2 was performed on the tumor, and only a TP53 mutation (TP53 p.R175H) was identified. The mutation was limited to the tumor nodule of FVPTC as shown by immunohistochemistry. This report represents the first extensive molecular study of a Pendred syndrome-associated thyroid carcinoma. The evidences support that thyroid carcinomas arising from dyshormonogenetic goiter require additional genetic alteration in addition to the purported thyroid-stimulating hormone (TSH) overstimulation. It is intrigue to note that the mutant p53 is involved in the development of a low-grade malignant thyroid tumor as FVPTC in this patient.

Mutations of TSHR and TP53 Genes in an Aggressive Clear Cell Follicular Carcinoma of the Thyroid.

Clear cell follicular carcinoma is a rare type of thyroid cancer and some with aggressive biological behavior. The cytoplasmic clearing of the neoplastic cells has been attributed to the accumulation of various substances, such as glycogen, lipid, mucin, and thyroglobulin, or distension of mitochondria or endoplasmic reticulum. However, the molecular mechanisms responsible for the characteristic appearance of the cell cytoplasm and the biological behavior remain unknown. We report here a case of aggressive clear cell follicular carcinoma of the thyroid with molecular profile using targeted next generation sequencing (NGS) that presented as a metastatic tumor in a woman with a history of breast carcinoma. The NGS data revealed the coexisting of a well-characterized loss-of-function TP53 R248Q mutation and a putative gain-of-function mutation of TSHR L272V, which was suggested by the overexpression of thyroglobulin and SLC5A5 (NIS) genes in this tumor. TP53 mutations are usually related with dedifferentiation, progression, and metastasis of thyroid carcinomas. Identification of TP53 R248Q in this tumor correlated with its aggressive clinical behavior. Gain-of-function mutation of TSHR can overstimulate the thyroid follicular cells as the elevated level of TSH does and might have contributed to the development of clear cell morphology in this tumor. This report represents the first case of clear cell follicular carcinoma of the thyroid with NGS analysis and more molecular characterization is needed to elucidate the pathogenesis and provide more prognosis-relevant information for this uncommon variant of thyroid carcinomas.

Oncogenic PIK3CA mutation and dysregulation in human salivary duct carcinoma.

Salivary duct carcinoma (SDC) is an aggressive malignant tumor with a high mortality, which resembles high-grade breast ductal carcinoma in morphology. The parotid gland is the most common location. Its molecular genetic characteristics remain largely unknown. We have previously reported high incidence of PIK3CA somatic mutations in head and neck squamous cell carcinoma, particularly in pharyngeal cancers. Here we examined the PIK3CA gene expression status and hotspot mutations in six cases of SDC by immunohistochemistry and genomic DNA sequencing. Immunohistochemistry showed that PIK3CA expression was elevated in all six patients with SDC. By DNA sequencing, two hotspot mutations of the PIK3CA gene, E545K (exon 9) and H1047R (exon 20), were identified in two of the six cases. Our results support that oncogenic PIK3CA is upregulated and frequently mutated in human SDC, adding evidence that PIK3CA oncogenic pathway is critical in the tumorigenesis of SDC, and may be a plausible drug target for this rare disease.

Validity and reliability of using a self-lavaging device for cytology and HPV testing for cervical cancer screening: findings from a pilot study.

UNLABELLED: Self-sampling could increase cervical cancer screening uptake. While methods have been identified for human papillomavirus (HPV) testing, to date, self-sampling has not provided adequate specimens for cytology. We piloted the validity and reliability of using a self-lavaging device for cervical cytology and HPV testing. We enrolled 198 women in New York City in 2008-2009 from three ambulatory clinics where they received cervical cancer screening. All were asked to use the Delphi Screener™ to self-lavage 1-3 months after clinician-collected index cytological smear (100 normal; 98 abnormal). Women with abnormal cytology results from either specimen underwent colposcopy; 10 women with normal results from both specimens also underwent colposcopy. We calculated sensitivity of self-collected cytology to detect histologically confirmed high grade lesions (cervical intraepithelial neoplasia, CIN, 2+); specificity for histology-negative (CIN 1 or lower), paired cytology negative, or a third cytology negative; and kappa for paired results. One hundred and ninety-seven (99.5%) women self-collected a lavage. Seventy-five percent had moderate to excellent cellularity, two specimens were unsatisfactory for cytology. Seven of 167 (4%) women with definitive results had CIN2+; one had normal and six abnormal cytology results with the self-lavage (sensitivity = 86%, 95% Confidence Interval, CI: 42, 100). The kappa for paired cytology was low (0.36; 95% CI: 0.25, 0.47) primarily due to clinician specimens with atypical squamous cells of undetermined significance (ASC-US) and low grade squamous intraepithelial lesion (LSIL) coded as normal using Screener specimens. However, three cases of HSIL were coded as ASC-US and one as normal using Screener specimens. Seventy-three women had paired high-risk HPV tests with a kappa of 0.66 (95% CI: 0.49, 0.84). Based on these preliminary findings, a larger study to estimate the performance of the Screener for co-testing cytology and HPV or for HPV testing with cytology triage is warranted. TRIAL REGISTRATION: ClinicalTrials.gov NCT00702208.

PAX8 and PAX2 immunostaining facilitates the diagnosis of primary epithelial neoplasms of the male genital tract.

PAX8 and PAX2 are cell-lineage-specific transcription factors that are essential for the development of Wolffian and Müllerian ducts and have recently emerged as specific diagnostic markers for tumors of renal or Müllerian origin. Little is known about their expression in the Wolffian duct-derived human male genital tract. We report our findings of PAX8 and PAX2 expression in the epithelium of the normal male genital tract and in epithelial tumors derived therefrom using immunohistochemistry (IHC). We found that PAX8 and PAX2 were expressed in the epithelium of the male genital tract from the rete testis to the ejaculatory duct. Rare glands in the prostatic central zone, a tissue of purported Wolffian duct origin, were focally positive for PAX2, but no PAX8 was detected in this area, a finding that may warrant further study. We found diffuse expression of PAX8 and PAX2 in 1 case each of serous cystadenoma of the epididymis, carcinoma of the rete testis, Wolffian adnexal tumor of the seminal vesicle, and endometrioid carcinoma of the seminal vesicle. Neither PAX8 nor PAX2 was detected in the seminiferous tubules and interstitium of the normal testis, nor in Leydig cell tumors (n=6), Sertoli cell tumors (n=2), or 48 of 49 germ cell tumors. One pediatric yolk sac tumor showed focal and weak staining for PAX8. Tumors of mesothelial origin, that is, adenomatoid tumors (n=3) and peritoneal malignant mesotheliomas (n=37) in men, were negative for PAX2 and PAX8. Neither PAX2 nor PAX8 was present in other areas of the prostate. Expression of PAX8 and PAX2 in these primary epithelial neoplasms of the male genital tract is due to their histogenetic relationship with Wolffian or Müllerian ducts. PAX8 and PAX2 IHC may facilitate the diagnosis of these tumors and should be included in the differential diagnostic IHC panel.

Pax8: a marker for carcinoma of Müllerian origin in serous effusions.

PAX8 is a nuclear transcription factor with limited expression in normal and neoplastic tissues in a cell lineage-dependent manner. PAX8 has been detected in embryonic Müllerian ducts, human fallopian tubes, and ovarian carcinomas. However, little is known about its expression in other areas of the female genital tract. In this study, we used immunohistochemistry (IHC) to examine PAX8 expression in the normal uterine corpus and cervix, malignant tumors arising from these sites, and malignant effusions. We reported here that PAX8 was also detected in endometrial epithelial cells and endocervical glands, with a lower expression level in the latter, but not in the stromal cells of these areas. All endometrial carcinomas (N = 52) were positive for PAX8, whereas endocervical adenocarcinomas (N = 5) and uterine leiomyosarcomas (N = 3) were negative for PAX8. PAX8 was detected in 70% (22/31) and 68.8% (11/16) of metastatic carcinomas of the ovary and endometrium in serous effusions, respectively. No PAX8 was detected in carcinomas of nongynecologic origin or noncarcinomas (N = 71) in serous effusions except in one renal-cell carcinoma and one carcinoma of unknown primary in a woman. In addition, papillary serous carcinomas of the peritoneum (N = 10) were diffusely positive for PAX8, implying a Müllerian origin similar to malignant tumors in the female genital tract. Our findings suggest that PAX8 is an additional IHC marker for carcinomas of Müllerian origin hence we recommend including PAX8 for evaluation of malignant serous effusions in women, especially when tumors of Müllerian origin are in the differential diagnosis.

Fine needle aspiration of pleomorphic lipoma of the neck: report of two cases.

Pleomorphic lipoma is a rare lipocytic neoplasm that most commonly occurs in the head and neck region in middle-aged to elderly men. Clinically, it presents as a slow-growing, well-circumscribed subcutaneous mass. Histopathologically and cytogenetically, it has some features overlapping with other benign and malignant tumors, such as benign spindle cell lipoma, atypical lipomatous tumor, liposarcoma, and malignant fibrous histiocytoma. However, cure rates are high when pleomorphic lipoma is treated with complete surgical excision with clear margins. Therefore, an accurate preoperative diagnosis is very important for proper treatment. Due to the rarity of this tumor, few cases diagnosed by cytology have been reported in the English literature. Here, we report two cases of pleomorphic lipoma, the diagnoses of which were suggested on fine needle aspiration biopsies and subsequently confirmed by surgical excisions.

Fine-needle aspiration cytology of subcutaneous toxoplasmosis: A case report.

Toxoplasmosis is a common opportunistic infection in patients with AIDS in whom it typically presents as encephalitis, pneumonia, lymphadenitis, and myocarditis. Skin involvement is very rare and, to our best knowledge, Toxoplasma gondii forming a subcutaneous mass has not been reported. Here, we report the findings of an interesting case of subcutaneous toxoplasmosis with the cytological appearance of an inflammatory fibrovascular lesion in a HIV-positive patient and discuss the differential diagnosis.

Expression of PAX8 in normal and neoplastic renal tissues: an immunohistochemical study.

Cell-lineage-specific transcription factors are a group of regulatory proteins expressed in embryonic, differentiated, or neoplastic cells of the same lineage and represent a valuable repertoire of tissue-specific markers for the diagnosis of human tumors. Together with PAX2, PAX8 is a nephric-lineage transcription factor and is required for the establishment of renal-lineage cells and the formation of the kidney. In contrast to PAX2, little is known about the expression of PAX8 in adult kidney and renal tumors. In this study, we used immunohistochemistry to investigate the expression of PAX8 in adult human kidney and renal epithelial tumors. We report here that PAX8 was detected in renal epithelial cells in all segments of renal tubules from the proximal tubules to the renal papillae and in the parietal cells of Bowman's capsule in the adult kidney. PAX8 was also present in 98% of clear cell renal cell carcinomas (RCCs), 90% of papillary RCCs, and 95% of oncocytomas, similar to PAX2. In addition, PAX8 was found in 82% of chromophobe RCCs, 71% of sarcomatoid components of RCCs, and 100% (2/2) of renal medullary carcinomas. Overall, PAX8 was detected in 85% of metastatic renal tumors. Interestingly, expression of PAX8 was noted in some urothelial cells in the renal pelvis and ureters and approximately 23% of urothelial carcinomas of the renal pelvis, but not in the urothelium or urothelial carcinomas of the urinary bladder; this probably underlines the different embryonic origins of urothelial cells in the upper and lower urinary tracts. As shown in this study, PAX8 is widely expressed in normal and neoplastic renal tissues. PAX8 may be a useful additional marker for renal epithelial tumors; however, its specificity and sensitivity await further investigation.

Expression of PAX8 in nephrogenic adenoma and clear cell adenocarcinoma of the lower urinary tract: evidence of related histogenesis?

Recent evidence has showed that nephrogenic adenoma is a true "nephrogenic" lesion derived from the proliferation of exfoliated and implanted renal tubular cells in the urinary tract, a process that closely resembles the formation of endometriosis. This new concept has led to the identification of renal transcription factor PAX2 as a diagnostic marker for nephrogenic adenoma. PAX8 is another transcription factor structurally and functionally related to PAX2. Both are cell lineage restricted transcription factors expressed in normal and neoplastic tissues of related origin, including renal tubular cells in both fetal and adult kidneys. In this study, we investigated the expression of PAX8 in nephrogenic adenoma and its mimics. We report here that PAX8 was detected in all nephrogenic adenomas (N=35) and clear cell adenocarcinoma of the lower urinary tract (N=7), but not in prostate adenocarcinoma (N=100), adenocarcinoma (N=9), squamous cell carcinoma (N=5), or urothelial carcinoma (N=48) of the urinary bladder and its variants. PAX8 was neither detected in normal urothelium of the urinary bladder nor in prostate glands and stroma. PAX2 was also detected in 2 of the 7 clear cell adenocarcinomas of the lower urinary tract. We suggest that PAX8 is an additional marker for identifying nephrogenic adenoma. Expression of PAX8 or PAX2 in both nephrogenic adenoma and clear cell adenocarcinoma of the lower urinary tract may indicate a possible related tissue origin for these 2 lesions; both may be derived from proliferating renal tubular cells in the urinary tract. In addition, detection of PAX8 or PAX2 in clear cell adenocarcinoma of the lower urinary tract is helpful in differentiating it from urothelial carcinoma and its variants and adenocarcinomas of the urinary bladder or of the prostate.

Fine-needle aspiration biopsy of primary osteosarcoma of the thyroid: report of a case and review of the literature.

Primary osteosarcoma of the thyroid is an extremely rare tumor, with only 27 well-documented cases reported in the literature, including only one in the cytology literature. We describe here an additional case with fine-needle aspiration biopsy findings. A 60-year-old woman presented with a 1-month history of progressive midline neck swelling. CT and ultrasound demonstrated a large thyroid mass with tracheal compression. Fine-needle aspiration biopsies were performed and showed pleomorphic spindle and epithelioid neoplastic cells, multinucleated giant cells, and scant metachromatic extracellular matrix material. Cell block sections contained minute tissue fragments with neoplastic spindle cells. Immunohistochemical stains showed the tumor cells to be positive for vimentin and negative for cytokeratins, TTF-1, calcitonin, synatophysin, chromogranin, and S-100 protein, suggesting a sarcoma; however, the differential diagnosis also included anaplastic thyroid carcinoma and medullary thyroid carcinoma. Tissue biopsy revealed a high-grade spindle cell neoplasm with osteoid production, consistent with osteosarcoma of the thyroid. The patient developed a large pulmonary embolus and superior vena cava syndrome and no further surgical intervention was performed. She died 5 weeks after the initial diagnosis. Upon retrospective review, the cytologic features resemble osteosarcoma in other areas. Although cytologic features on fine-needle aspiration biopsy may suggest a diagnosis of this rare entity, definitive diagnosis should be deferred to histologic examination.

Nephrogenic adenoma identified on urine cytology using PAX-2 immunostaining.

Urine cytology is a sensitive and specific method in detecting urothelial carcinoma of the urinary bladder, particularly the high-grade ones. However, the cytologic features of nonneoplastic lesions of the lower urinary tract, including nephrogenic adenoma, are nonspecific and may cause false positive diagnosis. Recent evidence has demonstrated that nephrogenic adenoma is a true "nephrogenic" lesion derived from the exfoliated and implanted renal tubular cells in the urinary tract. This has promoted the use of immunostaining of renal transcription factor PAX2 in tissue biopsies to differentiate nephrogenic adenoma from the common malignant tumors of the lower urinary tract. We report here that PAX2 immunostaining can also be used in urine cytology specimen to identify nephrogenic adenoma. Combination of PAX2 immunostaining and cytologic analysis may increase the accuracy in identifying this benign lesion in urine cytology specimen and therefore reduce unnecessary repeat cystoscopy and biopsy procedures. This may be a cost effective follow- up method for patients with an established diagnosis of nephrogenic adenoma.

Novel mutant-enriched sequencing identified high frequency of PIK3CA mutations in pharyngeal cancer.

We previously reported 4 PIK3CA mutations in 38 head and neck cancer samples, 3 of which were identified in 6 pharyngeal cancer samples. To determine the mutation frequency of PIK3CA in pharyngeal cancer, we studied 24 additional cases of pharyngeal squamous cell carcinoma in this study. Using both direct genomic DNA sequencing and novel mutant-enriched sequencing methods developed specifically for the 3 hot-spot mutations (H1047R, E545K and E452K) of PIK3CA, we detected 5 mutations of PIK3CA in the 24 pharyngeal cancers (20.8%). Three of the 5 mutations had been missed by the conventional sequencing method and were subsequently detected by novel mutant-enriched sequencing methods. We showed that the mutant-enriched sequencing method for the H1047R hot-spot mutation can identify the mutation in a mixed population of mutant and wild-type DNA sequences at 1:360 ratios. These novel mutant-enriched sequencing methods allow the detection of the PIK3CA hot-spot mutations in clinical specimens which often contain limited tumor tissues (i.e., biopsy specimens). The data further support that oncogenic PIK3CA may play a critical role in pharyngeal carcinogenesis, and the mutant-enriched sequencing methods for PIK3CA are sensitive and reliable ways to detect PIK3CA mutations in clinical samples. Because PIK3CA and its pathway are potential targets for chemotherapy and radiation therapy, and frequent somatic mutation of PIK3CA has been identified in many human cancer types (e.g., breast cancer, colorectal cancer), the abilities to detect PIK3CA mutations with enhanced sensitivities have great potential impacts on target therapies for many cancer types.

Expression of PAX2 in papillary serous carcinoma of the ovary: immunohistochemical evidence of fallopian tube or secondary Müllerian system origin?

PAX2 is a urogenital developmental transcription factor expressed in the Wolffian ducts, developing kidneys, and Müllerian ducts during embryonic stage. Its function in renal development is well documented and its clinical application in the diagnosis of lesions of renal origin has been reported recently. However, information on its role in the Müllerian-derived genital tract is sparse. In this study, we investigated the expression of PAX2 in human female genital tract using immunohistochemistry. We demonstrated that PAX2 was expressed specifically in the epithelial cells of fallopian tube, endometrial and endocervical glands, but not in the stromal tissues in these areas. PAX2 was detected in secondary Müllerian structures in the ovary, such as endometriotic and endosalpingiotic glands and rete ovarii, but not in ovarian surface epithelium, surface epithelium-derived inclusion cysts, stroma, or sex-cord-derived structures such as follicles, oocytes, and corpus luteum. In addition, PAX2 was detected in 67% of ovarian papillary serous carcinomas (N=36) but rarely in peritoneal malignant mesotheliomas, with two exceptions (N=54). Interestingly, the two PAX2-positive 'peritoneal malignant mesotheliomas' were from female patients and were positive for estrogen receptor. The significance of expression of PAX2 and estrogen receptor in these cases is under investigation. Taken together, we suggest that PAX2 is a novel Müllerian-specific epithelial marker when used in proper clinical settings. Identification of PAX2 in the majority of papillary serous carcinomas of the ovary but not in the ovarian surface epithelium or epithelium-derived inclusion cysts suggests that this malignant epithelial tumor may be directly derived from the primary or secondary Müllerian epithelium in or surrounding the ovary, rather than from the surface epithelium or its derivatives.