Fine-needle aspiration cytology of metastatic small cell carcinoma of the colon: a report of three cases

Extrapulmonary small cell carcinoma of the anal canal: a case report and review of the literature

Purpose. Extrapulmonary small cell carcinoma affecting the anal canal is a rare and poorly understood entity which can, in its early stages, masquerade as benign anorectal disease such as hemorrhoids. Methods. We report a case of this rare malignancy which initially presented with hematochezia and anal pain. We also review the literature with regard to previously described cases and management strategies including the role of surgery. Results. Despite aggressive multidisciplinary treatment consisting of chemotherapy and radiation, the disease progressed rapidly with dissemination occurring only three months after completion of treatment. Because of the aggressive nature of this tumor, the treatment options for this almost universally fatal malignancy are often palliative in nature. Conclusion. Chemoradiotherapy is likely the most reasonable approach to extrapulmonary small cell carcinoma of the anal canal given its aggressiveness.

Endoscopic ultrasound guided fine-needle aspiration diagnosis of duodenal high grade neuroendocrine carcinoma underlying a villous adenoma: report of a case

Endoscopic ultrasound guided fine-needle aspiration biopsy is a reliable and accurate method for the diagnosis of submucosal lesions of the gastrointestinal tract. We report the cytopathologic findings of a case of duodenal high-grade neuroendocrine carcinoma in a 68-year-old woman who presented with melena and marked anemia, 45 years after kidney transplantation. Imaging studies performed in the work-up of melena showed a duodenal mass, which on endoscopy proved to be an exophytic, villous duodenal lesion, 3 cm from the ampulla. Forceps biopsy of the exophytic lesion showed a villous adenoma. Endoscopic ultrasound additionally revealed an underlying submucosal lesion and EUS-guided fine needle aspiration of this submucosal mass and of the enlarged mesenteric lymph nodes was diagnostic of a high-grade neuroendocrine carcinoma. The aspirates showed abundant cellularity with tumor cells arranged in sheets and occasional loose clusters. The neoplastic cells had a moderate amount of pale cytoplasm and large round to oval hyperchromatic nuclei with focally prominent nucleoli. Mitoses, apoptotic bodies and necrotic debris were also present. The tumor cells were strongly and diffusely positive for cytokeratin AE1/AE3, synaptophysin and chromogranin and showed a very high proliferative fraction on Ki67 staining, supporting the diagnosis of a high-grade neuroendocrine carcinoma. This is to our knowledge the first case of high-grade neuroendocrine carcinoma of the duodenum diagnosed by EUS-FNA. This case also emphasizes the diagnostic value of EUS-FNA sampling of the submucosal and intramural component of villous tumors of the gastrointestinal tract when mucosal forceps biopsies show only benign findings.

Gastrointestinal tract cytology: advancing horizons

Tide and ebb of interest in gastrointestinal tract cytology has followed technical advances in this field over the last 60 years. Cytologic samples can be obtained using gastric lavage, abrasive balloons, mucosal brushing, and fine needle aspiration (under percutaneous image guidance, endoscope and endoscopic ultrasound guidance). These advances now allow simultaneous performance of brushing the abnormal mucosa, obtaining fine needle aspirates and excising mucosal biopsy samples for evaluation. Use of endoscopic ultrasound guided fine needle aspirates now help to obtain diagnosis of submucosal lesions, preoperative staging of gastrointestinal tract malignancies and help determine further management of patients. Such advances have brought pathologists to the forefront of the patient management team for the treatment of gastrointestinal tract lesions. This manuscript reviews the advantages and limitations of each cytology associated technique as well as reviews the salient diagnostic features, differential diagnosis and diagnostic pitfalls of gastrointestinal tract lesions. Finally, it suggests the modalities best suited to obtain diagnosis for various gastrointestinal tract lesions.

A review of cytologic findings in neuroendocrine carcinomas including carcinoid tumors with histologic correlation

BACKGROUND

The nosology of neuroendocrine neoplasia has evolved substantially in recent years. The aim of this study was to review the authors' institutional experience and diagnostic accuracy for cytologic specimens of neuroendocrine carcinoma (NEC) and to identify features most suggestive of neuroendocrine differentiation.

METHODS

The cytologic and histologic findings of 29 archival NEC in which cytology preceded biopsy or resection were compared. The study was comprised of 6 carcinoid tumors, 3 atypical carcinoid tumors, 17 high grade NEC (5 small cell, 9 large cell, and 3 mixed small/large cell), and 3 combined NEC/nonneuroendocrine carcinomas. Cytologic material was derived from 21 fine-needle aspirates (FNA), 6 bronchial brushing/washings, and 2 gastrointestinal tract brushings.

RESULTS

Of the 29 cases, the correct cytologic diagnosis was rendered in 11. Two cases were identified as NEC but were graded incorrectly. The remaining 16 cases were interpreted as nonsmall cell carcinoma (8 cases); diagnostic or suspicious of carcinoma, not otherwise specified (7 cases); and atypical, indeterminate for malignancy (1 case). On review, neuroendocrine features were identified in 14 of the latter 16 cases.

CONCLUSIONS

The cytologic diagnosis of NEC, both high and low grade, can be difficult. Because of acinus-like formations and columnar cell shapes, low grade NEC may be mistaken for adenocarcinoma. Small cell carcinomas, especially in bronchial brush and wash preparations, may be difficult to classify beyond malignant. Large cell NEC may be confused with nonneuroendocrine carcinomas because of abundant cytoplasm and nucleoli. Attention to the presence of loose cell aggregates in a background of singly dispersed cells; feathery patterns created by tumor cells clinging to capillaries; rosette formations; delicate, granular cytoplasm; inconspicuous nucleoli; molding in high grade tumors; and, most important, speckled or dusty chromatin patterns are useful in identifying neuroendocrine differentiation in cytologic specimens.

Small-cell carcinoma of the rectum: report of two cases

Small-cell carcinoma of the rectum is an infrequent pathologic finding, and its precise incidence is unknown. Its incidence is less than 0.2 percent among all colorectal cancers. This tumor manifests highly aggressive behavior. The treatment of choice is combination chemotherapy similar to that used for small-cell carcinoma of the lung, but in small localized tumors surgery plus chemotherapy is an alternative. We present two cases of small-cell carcinoma of the lower rectum and a review of the literature.

Fine-needle aspiration biopsy of metastatic small cell carcinoma from extrapulmonary sites

Like a pulmonary counterpart, extrapulmonary small cell carcinoma (SCC) is an aggressive tumor with a high rate of metastasis. Forty-nine fine-needle aspiration biopsies (FNABs) (36 patients) of various primary sites other than the lung diagnosed as metastatic SCC (including Merkel cell carcinoma) were reviewed. FNABs were derived from lymph nodes (20), liver (7), bone (2), breast (1), pancreas (1), and skin/soft tissue (18). Primary tumor sites included the prostate (14), skin (11; Merkel cell carcinoma), cervix (5), urinary bladder (3), urethra (1), ovary (1), and parotid (1). Aspirates revealed predominantly dispersed single tumor cells with occasional clustering. Tumor cells were small with scant cytoplasm, fine powdery chromatin, and inconspicuous nucleoli. Nuclear molding, mitotic figures, and apoptotic bodies were frequently observed. In four cases, findings from the FNABs were used to render the initial diagnosis of SCC. FNAB is useful for determining whether metastases contain a SCC component, a finding that may alter clinical management. Cytologically, SCC from different primary sites cannot be differentiated, and its distinction requires clinical and radiographic correlation.