Squamous cell carcinoma arising in a tall cell papillary carcinoma of the thyroid

Transformation of differentiated thyroid cancer into poorly differentiated carcinoma is rare. This report describes a case in which preoperative fine needle aspiration suggested a squamous cell carcinoma whereas needle core biopsy favoured an undifferentiated carcinoma of probable thyroid origin. Histology of the subsequent total thyroidectomy specimen revealed a biphasic tumour comprising areas of tall cell papillary carcinoma merging with moderately to poorly differentiated squamous cell carcinoma. The immunohistochemical findings are discussed in detail.     

Invasive urothelial carcinoma with squamous differentiation and associated high-risk human papilloma virus infection: Clinical,cytologic, and histologic features of a rare entity

We correlate the fine needle aspiration (FNA) cytologic findings with the histologic features of an invasive high-grade urothelial carcinoma showing squamous differentiation in the setting of high-risk Human Papilloma Virus (hrHPV) infection. To our knowledge, only extensive urinary bladder catheterization has been associated with hrHPV-positive urothelial carcinoma with squamous differentiation, and rarely at that. Herein, we present a case arising in a patient with only sparse and intermittent catheterization. A 69-year-old woman presented with voiding difficulties, and after continued symptoms, a Foley catheter was placed, and a cystoscopy procedure revealed two 1–2 cm inflammatory masses. Excisional biopsies were interpreted as papillary urothelial carcinoma. One month follow-up pelvic imaging demonstrated a new mass involving the urinary bladder neck, with irregular wall thickening and perivesical fat stranding, as well as probable vaginal involvement. CT-guided FNA (CT-FNA) to collect smears and core biopsies revealed an invasive urothelial carcinoma with squamous differentiation. HPV-cytopathic changes amid squamous metaplasia and dysplasia were noted on FNA smears with HPV E6/E7 RNA in situ hybridization (ISH) showing on the FNA core biopsy specimen. Immunostains showed that the tumor cells were positive for P16 (strong, diffuse), CK7, p63, ER, and GATA3 (patchy). Subsequent radical cystectomy revealed the extent of the patient's carcinoma, with direct extension to the vaginal wall, and involvement of the radial soft tissue resection margins. Describing the cytomorphologic features of a hrHPV positive urothelial carcinoma with squamous differentiation, without an extensive history of urinary catheterization or prior known history of HPV infection, emphasizes the role of cytopathology as a powerful diagnostic tool for recognizing a unique and unexpected lesion.     

Follicular adenoma with squamous metaplasia and cystic change: report of a case with fine needle aspiration cytological and histological features

Squamous metaplasia (SM) of thyroid follicular epithelium is known to occur in a variety of non-neoplastic lesions as well in thyroid neoplasms, notably papillary carcinoma (PC). In follicular thyroid tumors, on the other hand, SM is very rare. This case describes cytological and pathological findings in a follicular adenoma (FA) that presented as a cystic lesion with extensive SM. The fine needle aspiration (FNA) cytology sample in this case yielded only necrotic material from the cystic area and squamous cells, which being mostly of immature type, were not recognised as squamous in the cytological smears. The needle missed the solid (neoplastic) component of the lesion and on the whole the cytological picture was considered to be equivocal. FA can now be added to the spectrum of thyroid lesions that can show SM. Awareness of this will enable cytopathologists to consider non-papillary lesions in the differential diagnosis of thyroid nodules that yield squamous cells.     

Unusual small bone metastases from epithelial malignancies: Diagnosis by fine-needle aspiration cytology with histologic confirmation

Although epithelial malignancies can have bone metastases, involvement of small bones is exceedingly rare, representing either first manifestation of an occult carcinoma or late disseminated disease. Small bone metastases may mimic primary skeletal diseases leading to misdiagnosis and delayed treatment. We report three cases of metastatic epithelial malignancies diagnosed by computed tomography (CT)-guided fine-needle aspiration (FNA) biopsy in two patients with lytic calcaneal lesions and a patellar lesion in a third patient; all with histologic confirmation. Case 1, a 63-yr-old female, presented with heel pain. FNA and tissue biopsy of the calcaneus revealed a clear cell malignancy consistent with a renal primary. Follow-up abdominal CT scan revealed a renal lesion consistent with renal cell carcinoma. Case 2, a 37-yr-old male with squamous cell carcinoma of the esophagus, presented with foot pain. FNA and tissue biopsy of the calcaneus revealed metastatic squamous cell carcinoma. Case 3, a 52-yr-old male with a history of squamous cell carcinoma of floor of mouth, presented with knee pain and swelling. FNA and tissue biopsy of the patella revealed metastatic squamous cell carcinoma. To the best of our knowledge, this is the first complete FNA cytology report with histologic confirmation of unusual small bone metastases of the feet and patella from epithelial malignancies and shows the value of FNA cytology in establishing a correct diagnosis, and excluding primary skeletal diseases. © 1995 Wiley-Liss, Inc.     

Preoperative and intraoperative diagnosis of low-grade adenosquamous carcinoma of the breast: potential diagnostic pitfalls

AIMS: Low-grade adenosquamous carcinoma (LGAC), a rare variant of metaplastic breast cancer, may mimic benign or other low-grade malignant lesions histologically. Diagnostic difficulty may be encountered when evaluating breast cytology, core needle biopsy or intraoperative frozen section specimens. METHODS AND RESULTS: Pathology reports, cytology aspirates and histological slides of LGAC diagnosed at the Department of Pathology, Singapore General Hospital, were reviewed. Four cases of LGAC were analysed. Cytology from the first case showed atypical cells and the subsequent surgical excision specimen showed a complex sclerosing lesion with LGAC. The second and third cases were investigated by core needle biopsies: the preoperative histological features were suggestive of but not diagnostic of LGAC, until further excision biopsies were performed. The fourth case entailed a frozen section specimen, for which definitive diagnosis was deferred to paraffins. The patients remained well with no evidence of recurrent disease to date. CONCLUSIONS: When limited material, in the form of needle aspirates, core biopsy specimens or frozen sections, is submitted for histology, making a diagnosis of LGAC is not only challenging, but may be impossible. In difficult cases, careful pathological assessment, clinicopathological correlation and follow-up or complete excision biopsy may prove invaluable in establishing a definitive diagnosis.     

Epithelioid angiosarcoma of the ilium: a case report

Bone epithelioid angiosarcoma (EA) is rare and characterized by large, mildly to moderately pleomorphic epithelioid cells, with abundant eosinophilic cytoplasm, vesicular nuclei, and prominent nucleoli. The tumors may arise in various locations in bone and the patients may present with unifocal or multifocal osseous disease. We present a unifocal lesion case of EA of the ilium in a 62-year-old woman. A needle biopsy of the ilium was performed and first diagnosed poorly differentiated adenocarcinoma based on CKpan and CK18 immunopositivity. The tumor was treated initially with curettage followed by chemotherapy. The final diagnosis on the surgical specimen was epithelioid angiosarcoma.     

Subcutaneous tumor seeding following needle core biopsy of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common primary hepatic tumor and one of the most common cancers worldwide. At present, there are two widely used and accepted methods for obtaining diagnostic material for establishing the likelihood of malignancy in a hepatic mass, namely fine-needle aspiration (FNA) cytology and needle core biopsy (NCB). In recent years, however, tumor cell seeding along the needle tract has been shown to be a risk associated with using these procedures to obtain a pathologic diagnosis. We report a case of a patient who presented with a nodule in the anterior abdominal wall at the expected location of the previous NCB tract. FNA biopsy of the abdominal wall lesion confirmed the presence of malignant cells consistent with HCC. The finding of tumor seeding within a NCB tract raises the question of the role of NCB in the diagnostic workup of focal liver lesions.     

Usefulness of repeat cytology at the time of first colposcopy

The value of repeat cytology in the detection of high-grade preinvasive or invasive disease was analyzed at the time of colposcopy in cases of patients with abnormal referral cytology. A series of 136 patients with squamous abnormalities in their referral cytology, who had undergone repeat cytology and for whom outcome had been established, were included in the study. Final diagnosis consisted of 27 negative results (20%), 37 cases of CIN1 (27%), 31 CIN2 (23%), 39 CIN3 (29%), and 2 (1%) cases of squamous cell carcinoma (SCC). Referral and repeat cytology suggestive of atypical squamous cells cannot exclude high-grade squamous intraepithelial lesion (ASC-H), high-grade squamous intraepithelial lesion (HSIL) were findings significantly associated with a final diagnosis of CIN2 or worse. Sensitivity and positive predictive value of repeat cytology for the histological diagnosis of significant histological neoplasia (CIN2 or worse) were 81.9% and 77.6%, respectively. In women with referral cytology findings of atypical squamous cells of undetermined significance or low-grade squamous intraepithelial lesion (ASC-US/LSIL), repeat cytology was suggestive of HSIL in 20% of cases (11/54), and in 4% (2/54) biopsy was negative or CIN1, and the final diagnosis established by LLETZ was CIN3. Eight cases (10%) of HSIL in referral and repeat cytology in which biopsies were negative or insufficient were diagnosed as CIN3 or worse in the final diagnosis. Repeat cytology would have changed therapeutic management in 4 and 10%, respectively, of patients included as ASC-US/LSIL and ASC-H/HSIL in referral cytology.     

Cytological challenges in the diagnosis of intrathyroidal parathyroid carcinoma: A case report and review of literature

Parathyroid carcinoma is an uncommon malignancy and the probability of an intrathyroidal location is low. Fine needle aspirations (FNA) of these presumably “thyroid nodules” can lead to misinterpretation because of the similarities in cytological features of parathyroid and thyroid lesions. Despite limitations, USG guided FNA cytology remains the first line of investigation. We report a case of intrathyroidal parathyroid carcinoma presenting with hypercalcemia and elevated serum parathormone. Cytological findings attributed it to a possible parathyroid lesion and histopathology revealed a parathyroid carcinoma. It is reported due to its rare occurrence on FNA along with brief literature review.     

A case of interdigitating dendritic cell sarcoma/histiocytic sarcoma – a diagnostic pitfall

Interdigitating dendritic cell sarcoma (IDCS) and histiocytic sarcoma (HS) are two distinct rare hematolymphoid neoplasms, and HS derived from a likely pre-existing IDCS has never been reported in the English literature. Diagnosis of such entities in excised specimens is difficult, but becomes more difficult with the scant amount of materials obtained with fine needle aspiration (FNA) and core needle biopsy. Here we present an interesting and unique case of an IDCS located within a mesenteric mass, which was initially diagnosed as IDCS from the cytology of FNA and core needle biopsy specimens. After brief chemotherapy, the patient again developed abdominal pain, and a HS was diagnosed based on the excised segmental small intestinal specimen. While the exact relationship between the IDCS and HS cannot be ascertained, it is most likely that the HS is derived from the IDCS, although co-existing HS in addition to IDCS from the cytology specimen cannot be completely ruled out.     

Fine‐needle aspiration biopsy of HPV‐related squamous cell carcinoma of the head and neck: Current ancillary testing methods for determining HPV status

Human papillomavirus (HPV)‐related head and neck squamous cell carcinoma (HNSCC) is a unique form of carcinoma that largely arises from the tonsillar tissue in the oropharynx. These tumors often present with cervical lymphadenopathy resulting in a fine needle aspiration (FNA) biopsy. Use of the cytology specimen to determine the HPV‐status has significant prognostic and treatment implications as HPV‐related tumors have a more favorable prognosis and response to nonsurgical therapies. While several different ancillary testing methods are available that have proven effective for determining HPV status in FNA specimens from HNSCCs, there is currently no consensus regarding HPV testing in this setting. Diagn. Cytopathol. 2017;45:221–229. © 2016 Wiley Periodicals, Inc.     

Cytopathologic characteristics of SMARCB1 (INI‐1) deficient sinonasal carcinoma: A potential diagnostic pitfall

Tumors of the head and neck are extremely diverse and a subset are poorly differentiated and difficult to classify. Recently, a new entity has been described with rhabdoid and/or plasmacytoid cytologic features and a characteristic genetic signature—inactivation of the SMARCB1 (INI‐1) tumor suppressor gene. To date, only 16 cases of SMARCB1 (INI‐1) deficient sinonasal carcinoma have been described, and there are currently no reports of the cytopathologic features by fine needle aspiration (FNA) cytology. A case of a 77‐year‐old man who presented with a posterior ethmoid sinus lesion with invasion into the skull base and bone was reported. FNA cytology of a right retropharyngeal lymph node revealed relatively monomorphic, loosely cohesive clusters of plasmacytoid cells with occasional nucleoli, rare intranuclear cytoplasmic inclusions, and mitotic figures in a background of necrosis and absence of overt squamous or glandular differentiation. A diagnosis of metastatic myoepithelial carcinoma was made; however, retrospectively, the surgical excision showed loss of the SMARCB1 (INI‐1) tumor suppressor gene by immunohistochemistry. In summary, the cytomorphologic features of SMARCB1 (INI‐1) deficient sinonasal carcinoma are relatively nonspecific and overlap with other regional tumors, including myoepithelial neoplasms. As a result, this entity should be considered in the differential diagnosis for a plasmacytoid tumor arising in the sinonasal tract by FNA cytology. Diagn. Cytopathol. 2016;44:700–703. © 2016 Wiley Periodicals, Inc.     

Bronchoscopic and transthoracic cytology and biopsy for pulmonary nonsmall cell carcinomas: performance characteristics by procedure and tumor type

Recent advances have increased the demand for the accurate diagnosis of pulmonary nonsmall cell carcinoma (NSCLC) rendered by biopsy or cytology. However, precise classification is not possible in all cases. In this study, we investigated the performance characteristics of preresection bronchoscopic and transthoracic procedures for the diagnosis of NSCLC. The pathology files were searched for resected NSCLCs and carcinoid tumors with corresponding preresection cytology and/or biopsy cases. The preresection diagnoses were correlated with the resection diagnosis and the type of bronchoscopic or transthoracic procedure. Among the bronchoscopic procedures, endobronchial/transbronchial biopsy (ETBX) had the highest yield for obtaining a positive (malignant) diagnosis and was the best procedure for obtaining precise classification. For transthoracic procedures, fine-needle aspiration (FNA) and needle core biopsy (NCB) were similar in providing a positive (malignant) diagnosis; however, NCB was better than FNA in obtaining precise classification. From the perspective of the neoplasms, carcinoid tumors yielded a positive (malignant) specimen with accurate classification most often (e.g., 100% by ETBX). This was followed by squamous cell carcinoma and adenocarcinoma. In contrast, precise classification was not possible for adenosquamous carcinoma, large cell carcinoma, and large cell neuroendocrine carcinoma. Bronchoscopic and transthoracic procedures have different performance characteristics. Furthermore, the diagnostic yield is dependent on the histologic type of the neoplasm. While carcinoid tumors are accurately classified in most cases, some other neoplasms are difficult to diagnose and subclassify due to histologic complexity, poor differentiation, or sampling limitations.     

Aspiration biopsy of osseous metastasis of occult hepatocellular carcinoma: Case report, literature review, and differential diagnosis

Fine-needle aspiration (FNA) cytology is a reliable technique for rapid diagnosis in virtually every organ of the body, including bone lesions. We report on the FNA findings in a 61-yr-old male of an osteolytic sacral lesion, which determined the diagnosis of an unsuspected metastatic hepatocellular carcinoma. In this case, the diagnosis was confirmed by FNA biopsy without resorting to surgical biopsy.     

Endobronchial ultrasound‐guided fine‐needle aspiration cytology of bronchial low‐grade mucoepidermoid carcinoma: Rapid on‐site evaluation of cytopathologic findings

Bronchial mucoepidermoid carcinoma (MEC) is rare, comprising about 0.2% of primary lung tumors. Endobronchial ultrasound (EBUS) guided fine‐needle aspiration (FNA) cytology is an integral tool in the diagnosis and staging of malignant lung tumors. Rapid on‐site evaluation (ROSE) has been proven useful as a guide for assessing the adequacy and accuracy of the FNA samples. Therefore, comprehensive knowledge of diagnostic cytomorphologic findings of MEC is critical for ROSE. We reported a 46‐year‐old woman with 6 weeks of cough productive of yellow sputum that did not improve on antibiotics. A chest CT demonstrated a well‐circumscribed nodule in the right lower lobe bronchus that extended into the lung parenchyma. EBUS‐guided FNA was performed to obtain diagnostic materials. The ROSE of cytology specimen revealed numerous tight clusters of cells with well‐defined, but scant cytoplasm. These cells were relatively small and bland with high N/C ratio, resembling benign ductal cells. Neither cilia nor intranuclear inclusions were noted. Focal extracellular metachromatic mucinous materials were also noted. A preliminary diagnosis of “low‐grade epithelial neoplasm, favor low grade MEC” was rendered. The definitive diagnosis was confirmed by both cytology and core biopsy. EBUS‐guided FNA cytology can be a reliable method for the diagnosis of bronchial low grade MEC. The cyto‐morphology of ROSE can indicate the diagnosis of low grade MEC and direct the appropriate follow‐up triage of the specimen.Diagn. Cytopathol. 2013;41:1096–1099. © 2012 Wiley Periodicals, Inc.     

Malignant rhabdoid tumor: Cyto-histologic correlation and immunohistochemical characterization of a rare pediatric malignancy and its differential diagnoses

Malignant rhabdoid tumor of the kidney (MRTK) is a rare aggressive pediatric renal tumor which can be diagnosed via fine-needle aspiration (FNA) cytology and core biopsy. The diagnosis of MRTK is challenging, and requires morphologic, immunohistochemical and clinical correlation to distinguish it from other entities. The differential diagnosis includes Wilms tumor, desmoplastic small round cell tumor, rhabdomyosarcoma, synovial sarcoma, renal medullary carcinoma, and epithelioid sarcoma. Here we describe a case of MRTK diagnosed on renal cytology and core biopsy with immunohistochemistry and follow by nephrectomy with gross and morphologic findings.     

Differential Expression of a Set of Genes in Follicular and Classic Variants of Papillary Thyroid Carcinoma

Fine-needle aspiration biopsy (FNA) is currently the best initial diagnostic test for evaluation of a thyroid nodule. FNA cytology cannot discriminate between benign and malignant thyroid nodules in up to 30% of thyroid nodules. Therefore, an adjunct to FNA is needed to clarify these lesions as benign or malignant. Using differential display-polymerase chain reaction method, the gene expression differences between follicular and classic variants of papillary thyroid carcinoma (PTC) and benign thyroid nodules were evaluated in a group of 42 patients. Computational gene function analyses via Cytoscape, FuncBASE, and GeneMANIA led us to a functional network of 17 genes in which a core sub-network of five genes coexists. Although the exact mechanisms underlying in thyroid cancer biogenesis are not currently known, our data suggest that the pattern of transformation from healthy cells to cancer cells of PTC is different in follicular variant than in classic variant.