Cutaneous pseudolymphoma: an unusual presentation of a scalp mass.

The term cutaneous pseudolymphoma (CPL), an accumulation of lymphocytes in response to a foreign antigen or unknown stimuli lacks specificity, and has been used when neither cause nor mechanism for the lymphocytic proliferation has been identified. Cases of childhood CPL are rare and require extensive investigation because of their potential for malignant transformation. We report a case of a child with a scalp mass diagnosed as CPL.

Ciliated foregut cyst of pancreas: cytologic findings on endoscopic ultrasound-guided fine-needle aspiration.

The cytologic findings of a ciliated foregut cyst of the pancreas diagnosed by endoscopic ultrasound-guided fine-needle aspiration (FNA) are described. Cytologic features of ciliated foregut cysts include the presence of ciliated columnar cells and detached ciliary tufts in a cystic fluid background with amorphous debris and rare macrophages. These cytologic findings are clearly distinct from those of cystic mucinous neoplasms and other pancreatic cysts with which the ciliated foregut cyst may be confused. To the best of our knowledge, this is the first case reporting the cytologic findings of a pancreatic ciliated foregut cyst sampled by endoscopic ultrasound-guided FNA. We believe that the distinctive and characteristic cytologic features can allow a preoperative cytologic diagnosis of this highly unusual pancreatic cystic lesion.

Rapid assessment of fine needle aspiration and the final diagnosis--how often and why the diagnoses are changed.

BACKGROUND: On-site rapid interpretation (RI) of fine needle aspiration (FNA) has been shown to increase the diagnostic yield of FNA and decrease the need for repeat diagnostic procedures. Because the pathologist interprets only a fraction of the sample and has limited resources available at such times, an occasional RI diagnosis will be changed at the time of the final diagnosis. We investigated how often these changes in diagnoses occur and the possible reasons for the changes. METHODS: All cytology reports from 1/1/02 to 12/31/03 from a single institution were reviewed. Cases with RI with discrepant final diagnoses were noted. The discrepant diagnoses were categorized depending on how they were changed. Possible sources for changed diagnoses were noted. RESULTS: Between 1/1/02 and 12/31/03 there were 1368 RIs of FNAs. Of these 80 (5.8%) had discrepancies between the RIs and final diagnoses. Seventy-eight cases had additional slides and/or cell block at time of final diagnosis. 16 cases had ancillary studies available at final diagnosis. Consultant pathologists were used in 7 cases. Different pathologists interpreted the RI and final diagnosis in 31 cases. CONCLUSION: Although uncommon, discrepancies between RIs and final diagnoses occur 5.8% of the time at our institution. Most commonly, this involves a change of diagnosis from either "non-diagnostic" or "benign" to "malignancy". Although much of this is likely due to the presence of additional material and information at the time of final diagnosis, the number of cases that had different pathologists involved in the RI and final diagnosis suggests that inter-observer variability may also play some role.

Interobserver variability with the interpretation of thyroid FNA specimens showing predominantly Hürthle cells.

Fine-needle aspiration (FNA) is used for the diagnosis and triaging of thyroid lesions. Recently, it has been shown that the pathologic interpretation of selected thyroid specimens can show a high degree of interobserver variability (IV). Because Hürthle cells may be seen in neoplastic and nonneoplastic disease, we investigated whether pathologists consistently interpret FNA specimens from these lesions. In the present study, 22 FNA specimens that showed Hürthle cells as the predominant cell type were reviewed by 7 pathologists. Cytologic features were assessed semiquantitatively. IV was calculated, and individual case diagnoses were compared with cytologic features. IV was high before diagnoses were collapsed into like diagnoses and triage recommendations (k = 0.17, 0.44, and 0.51, respectively). Overall cellularity, number of Hürthle cells, and number of lymphocytes all correlated with collapsed diagnostic agreement, and the number of air-dried rapid Romanowsky-stained slides, overall cellularity, number of Hürthle cells, and number of lymphocytes all correlated with collapsed triage recommendations.

Cytology of pancreatic acinar cell carcinoma.

Acinar cell carcinoma (ACC) of the pancreas is extremely uncommon and its cytologic features have rarely been described. We describe the cytologic features of cases we have seen, review the literature regarding its cytologic features and discuss the pitfalls that may be encountered and the use of immunohistochemistry for its diagnosis. We searched our databases for all cases of histologically confirmed pancreatic ACC which had undergone prior fine needle aspiration (FNA) of the primary pancreatic lesion. The clinical histories, radiographic and sonographic findings, cytologic features, original cytologic diagnoses, and final histologic diagnoses were reviewed. Four cases of pancreatic ACC were found that had undergone FNA prior to histologic confirmation of the diagnoses. They were from 2 men and 2 women aged 50-75 yr. All masses were in the head of the pancreas, 2 had apparent peri-pancreatic adenopathy and 1 had an apparent liver metastasis. On review, all 4 had had diagnostic material on cytology samples. Original cytologic diagnoses included "acinar cell carcinoma," "pancreatic endocrine tumor," "favor neuroendocrine tumor, low-grade" and "non-diagnostic specimen." The cytologic features included small to moderate-sized loose groups with numerous single cells, prominent acinar formation, little anisonucleosis and prominent nucleoli. The cytologic features showed significant overlap with those of pancreatic endocrine tumors.

Fine-needle aspiration cytology of pancreatic somatostatinoma: the importance of immunohistochemistry for the cytologic diagnosis of pancreatic endocrine neoplasms.

Pancreatic somatostatinoma is a rare pancreatic endocrine neoplasm representing as little as 1% of pancreatic endocrine neoplasms (PENs). The histologic features of this tumor are like those of other PENs, except that it commonly forms acinar structures and often has cells with abundant, granular cytoplasm. We have recently encountered two of these neoplasms sampled by endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA). We discuss the cytologic and immunohistochemical findings of these two cases and the cytologic similarities these neoplasms share with pancreatic acinar-cell carcinoma (PACC). We review the cytologic features of PEN and PACC and discuss the importance of cell block immunohistochemistry in the diagnosis of pancreatic neoplasia sampled by EUS-guided FNA.

Diffusion abnormalities of the globi pallidi in manganese neurotoxicity.

Manganese is an essential trace metal required for normal central nervous system function, which is toxic when in excess amounts in serum. Manganese neurotoxicity has been demonstrated in patients with chronic liver/biliary failure where an inability to excrete manganese via the biliary system causes increased serum levels, and in patients on total parenteral nutrition (TPN), occupational/inhalational exposure, or other source of excess exogenous manganese. Manganese has been well described in the literature to deposit selectively in the globi pallidi and to induce focal neurotoxicity. We present a case of a 53-year-old woman who presented for a brain MR 3 weeks after liver transplant due to progressively decreasing level of consciousness. The patient had severe liver failure by liver function tests and bilirubin levels, and had also been receiving TPN since the transplant. The MR demonstrated symmetric hyperintensity on T1-weighted images in the globi pallidi. Apparent diffusion coefficient (ADC) map indicated restricted diffusion in the globi pallidi bilaterally. The patient eventually succumbed to systemic aspergillosis 3 days after the MR. The serum manganese level was 195 mcg/l (micrograms per liter) on postmortem exam (over 20 times the upper limits of normal). The patient was presumed to have suffered from manganese neurotoxicity since elevated serum manganese levels have been shown in the literature to correlate with hyperintensity on T1-weighted images, neurotoxicity symptoms, and focal concentration of manganese in the globi pallidi. Neuropathologic sectioning of the globi pallidi at autopsy was also consistent with manganese neurotoxicity.