Cutaneous Deciduosis: A Rare Cutaneous Lesion Mimicking Malignancy.

ABSTRACT: Cutaneous deciduosis is an extremely rare condition that clinically presents as a nodular lesion in the skin as a scar or neoplasm. Histologically, this may pose a diagnostic challenge simulating malignant epithelioid neoplasms including sarcoma. Histologically, a nodular growth pattern of large monomorphic epithelioid cells is observed. The epithelioid cells in deciduosis can appear atypical with considerable nuclear pleomorphism, mimicking a malignancy. These features can be misinterpreted as a primary cutaneous or metastatic malignancy by dermatopathologists who are not familiar with gynecologic pathology. Failure to correctly diagnose this condition may result in unnecessary diagnostic studies for the patient. In this article, we report a case of cutaneous deciduosis in a 35-year-old woman with a cesarean scar. Histological examination revealed nodular proliferation of large epithelioid cells with pale eosinophilic cytoplasm and large nuclei with prominent nucleoli. Compressed atrophic slit-like glands resembling endometrial glands were present in some areas. Histopathological features of decidual cells, along with appropriate immunohistochemical studies, help establish the diagnosis and rule out other neoplastic mimics of deciduosis.

Validation of a natural language processing algorithm to identify adenomas and measure adenoma detection rates across a health system: a population-level study.

BACKGROUND AND AIMS: Measuring adenoma detection rates (ADRs) at the population level is challenging because pathology reports are often reported in an unstructured format; further, there is significant variation in reporting methods across institutions. Natural language processing (NLP) can be used to extract relevant information from text-based records. We aimed to develop and validate an NLP algorithm to identify colorectal adenomas that could be used to report ADR at the population level in Ontario, Canada. METHODS: The sampling frame included pathology reports from all colonoscopies performed in Ontario in 2015 and 2016. Two random samples of 450 and 1000 reports were selected as the training and validation sets, respectively. Expert clinicians reviewed and classified reports as adenoma or other. The training set was used to develop an NLP algorithm (to identify adenomas) that was evaluated using the validation set. The NLP algorithm test characteristics were calculated using expert review as the reference. We used the algorithm to measure ADR for all endoscopists in Ontario in 2019. RESULTS: The 1450 pathology reports were derived from 62 laboratories, 266 pathologists, and 532 endoscopists. In the training set, the NLP algorithm for any adenoma had a sensitivity of 99.60% (95% confidence interval (CI), 97.77-99.99), specificity of 99.01% (95% CI, 96.49-99.88), positive predictive value of 99.19% (95% CI, 97.12-99.90), and F1 score of .99. Similar results were obtained for the validation set. The median ADR was 33% (interquartile range, 26%-40%). CONCLUSIONS: When we used a population-based sample from Ontario, our NLP algorithm was highly accurate and was used at the system level to measure ADR.

Mixed Epithelial and Stromal Tumor: A Rare Renal Neoplasm-Case Report with Clinicopathologic Features and Review of the Literature.

Mixed epithelial and stromal tumor (MEST) is a rare benign renal neoplasm composed of epithelial and stromal components. Here, we report a 61-year-old woman presenting with a left complex cystic renal mass. The lesion was found incidentally on ultrasound for abdominal discomfort. CT scan and MRI showed a 7.4 cm complex cystic lesion in the left kidney. The differential diagnoses included complex renal cyst and cystic renal cell carcinoma. Laparoscopic nephrectomy showed a large 7.5 cm multicystic tumor with thick and thin septae and smooth walled-cysts containing clear watery fluid. Histologic examination showed variable sized cysts lined by flattened, cuboidal to columnar epithelium with focal hobnailing. No significant cytologic atypia or mitoses were noted. The cyst lining epithelium was positive for CK7 and high molecular weight cytokeratin (34Be12). The stroma was positive for alpha smooth muscle actin, CD10, estrogen receptor, and progesterone receptor. This report contributes an additional case to our collective knowledge of these lesions and summarizes the literature around these rare neoplasms.

A Challenging Case of Mammary Analogue Secretory Carcinoma: Case Study with Ultrastructural and Cytogenetic Correlation.

Mammary analogue secretory carcinoma (MASC) is a rare salivary gland tumor analogous to secretory carcinoma of the breast. The diagnosis of MASC can be challenging due to substantial morphologic and immunohistochemical similarities with other salivary gland tumors. The differential diagnosis of MASC is broad and includes intraductal carcinoma, acinic cell carcinoma, and adenocarcinoma, not otherwise specified. Although molecular testing for ETV6 gene rearrangement is characteristic of MASC and has not been shown in any other salivary gland tumor, a particular challenge arises when such testing is unavailable, or when molecular testing for ETV6 gene rearrangement is negative in a suspected case of MASC. Our study presents the diagnostic workup of a challenging case of MASC with immunohistochemistry, electron microscopy, and cytogenetic studies performed to resolve the diagnosis.

Coccidioides immitis: two cases of misidentified mycosis.

In the present report, two cases of pulmonary coccidioidomycosis that caused a diagnostic confusion are presented. The first case was initially misdiagnosed as nonsmall cell carcinoma, and both cases were initially misidentified as blastomycosis because of the presence of an atypical morphological form of Coccidioides immitis.

Primary small cell carcinoma of the ureter.

Primary small cell carcinoma of the ureter is a rare clinico-pathological entity. We present a report of primary ureteric small cell carcinoma and pathological correlates.

Urological manifestations of BK polyomavirus in renal transplant recipients.

OBJECTIVES: BK polyomavirus (BKV) disease in renal transplant recipients has become an increasingly problematic clinical entity. Complications of BKV disease lead to chronic allograft nephropathy and ultimately loss in greater than 50% of cases. We reviewed our experience with BKV disease over a 5-year period. PATIENTS AND METHODS: We performed 155 cadaveric and 168 live-related transplants between January 2000 and June 2005. During this period, seven patients had biopsy-confirmed BKV disease, which compromised the renal function of six cadaveric and one live-related renal transplant recipients. BKV was suspected as a potential cause of renal function deterioration after eliminating other possibilities. BKV was then confirmed by detecting viral DNA in urine samples by polymerase chain reaction (PCR) and visualizing viral particles in allograft biopsies by electron microscopy. RESULTS: The deterioration of allograft function in five renal transplant recipients was due to polyomavirus-associated nephropathy and two due to ureteric stenosis. Upon confirmation of BKV, overall immunosuppression was reduced or modified with follow-up of 5 to 44 months. However, additional rescue therapies were used to stabilize allograft function including ciprofloxacin, intravenous immunoglobulin, and leflunomide. One patient died and another lost his allograft due to non-compliance and reverted to hemodialysis, but renal function in the remaining five allografts has remained stable at higher serum creatinine levels. CONCLUSIONS: The management of BKV disease in renal transplant recipients is not yet clearly defined. However, early recognition of urological sequelae and modification of immunosuppressive therapy are essential to ensure adequate long-term function of these allografts.

Telepathology for routine light microscopic and frozen section diagnosis.

Telepathology (TP) uses telecommunication linkages to electronically capture, store, retrieve, and transmit images to distant sites. We assessed the feasibility of a dynamic real-time TP system for light microscopic (LM) diagnosis of anatomic pathology specimens, including frozen sections. Six pathologists, in 2 separate periods, read a set of 160 retrospectively retrieved slides (80 of which were frozen sections) by TP and LM. Reading times were recorded. Diagnoses were compared with the reference diagnosis (established by a group of 5 independent pathologists) and graded on a scale of 0 to 2 (2, correct; 1, incorrect but no clinical impact; 0, incorrect with clinical impact). Overall, LM was more accurate than TP compared with the reference diagnosis (score, 1.68 vs 1.54). There was no difference in accuracy between frozen section and paraffin-embedded tissue. Intraobserver agreement ranged from 82.5% to 88.2%. The average reading time was 6.0 minutes for TP and 1.4 minutes for LM. During the study, reading time decreased for TP but not for LM. These results show that despite marginally lower accuracy and longer reading times, TP isfeasible for routine light microscopic diagnosis, including frozen sections.

Undifferentiated sarcoma of the parotid gland with osseous metaplasia.

Malignant spindle cell tumors of the parotid gland are a diagnostic challenge. We present an unusual case of such a tumor that occurred in the right parotid gland of a 53-year-old man. The clinical and histologic assessments were consistent with a primary sarcoma of the parotid gland. The tumor was composed of sheets of pleomorphic, spindle-shaped cells with an area of bone formation. By immunohistochemistry, the tumor cells were positive for vimentin and negative for epithelial markers. Electron microscopy revealed mesenchymal cells containing moderate amounts of rough endoplasmic reticulum. The major differential diagnostic considerations were spindle cell carcinoma, carcinosarcoma, and primary undifferentiated sarcoma with osseous metaplasia. The lack of epithelial features and the benign appearance of the bone formation led to a diagnosis of undifferentiated sarcoma of the parotid gland.

RhoA/Rho-kinase contribute to the pathogenesis of diabetic renal disease.

OBJECTIVE: Accumulation of glomerular matrix proteins is central to the pathogenesis of diabetic nephropathy, with resident mesangial cells (MCs) known to upregulate matrix protein synthesis in response to high glucose. Because activation of the GTPase RhoA has been implicated in matrix upregulation, we studied its role in induction of the matrix protein fibronectin in diabetic MCs and in vivo in diabetic nephropathy. RESEARCH DESIGN AND METHODS: Glucose (30 mmol/l)-induced RhoA/Rho-kinase, AP-1 activation, and fibronectin upregulation were assessed by immunoblotting, luciferase, electrophoretic mobility shift assay, enzyme-linked immunosorbent assay, real-time PCR, Northern blots, and immunofluorescence. Streptozotocin-induced diabetic rats were treated with the rho-kinase inhibitor fasudil, which was compared with enalapril, and functional and pathologic parameters were assessed. RESULTS: Glucose led to RhoA and downstream Rho-kinase activation. Mannitol was without effect. Activity of the transcription factor AP-1, increased in diabetic MCs and kidneys, is important in the profibrotic effects of glucose, and this was dependent on Rho-kinase signaling. Upregulation of fibronectin by glucose, shown to be mediated by activator protein-1 (AP-1), was prevented by Rho-kinase inhibition. RhoA siRNA and dominant-negative RhoA also markedly attenuated fibronectin upregulation by high glucose. Applicability of these findings were tested in vivo. Fasudil prevented glomerular fibronectin upregulation, glomerular sclerosis, and proteinuria in diabetic rats, with effectiveness similar to enalapril. CONCLUSIONS: High glucose activates RhoA/Rho-kinase in MCs, leading to downstream AP-1 activation and fibronectin induction. Inhibition of this pathway in vivo prevents the pathologic changes of diabetic nephropathy, supporting a potential role for inhibitors of RhoA/Rho in the treatment of diabetic renal disease.

The value of postmortem examination in cases of metastasis of unknown origin-20-year retrospective data from a tertiary care center.

BACKGROUND: Metastasis of unknown origin (MUO) is a diagnostic challenge in clinical practice even with the state of current advanced diagnostic technology. To evaluate the value of autopsy in determining the primary site of MUO, this study reviewed the Hamilton experience-over the last 20 years-with patients autopsied with clinical diagnosis of MUO. METHODS: All autopsy diagnoses from cases performed at the Hamilton Health Sciences Center and St Joseph's Healthcare from 1980 to 2000 were reviewed. Fifty-three cases of MUO were identified (MUO was defined as a patient with pathological and/or radiological diagnosis of a metastatic tumor for which the primary site of malignancy was unknown). The clinical history and gross and microscopic diagnoses for these cases were reviewed. RESULTS: There were 31 men (58.5%) and 22 women (41.5%) in the study. Their mean age was 66 years. Pathological diagnoses at autopsy were adenocarcinoma (n = 37), small cell carcinoma (n = 6), anaplastic carcinoma (n = 3), and undifferentiated carcinoma (n = 3). Primary tumors were identified in 27 patients (51%), most commonly in the lung (n = 8), large bowel (n = 6), and pancreas (n = 4). Histochemical and immunohistochemical stains were helpful in reaching the diagnosis of a primary tumor in 4 of 27 cases. CONCLUSIONS: The following were observed: (1) in this series, autopsy was helpful in establishing the diagnosis of a primary tumor in 51% of the cases, reaffirming the value of postmortem examination in these instances; (2) adenocarcinoma was the most frequent tumor presenting as MUO; (3) the lung and the large bowel were the most frequent sites for primary tumors; and (4) careful gross and histological examinations remain the most important tools in identifying the primary site.

Congenital orbital and disseminated extrarenal malignant rhabdoid tumor.

A 5-week premature infant boy with tumorous malformations underwent biopsy of two truncal masses and exenteration of the left orbit. Specimens were examined histologically. Histologic reports, slides, and clinical photographs were reviewed. A diagnosis of malignant rhabdoid tumor was made. Malignant rhabdoid tumors can present as local or disseminated neoplastic disease involving the orbit and should be considered in the differential diagnosis of rapidly progressing orbital lesions presenting in early infancy. We review the current classification of rhabdoid tumors and the previous literature on orbital rhabdoid tumors.

Comparison of voice-automated transcription and human transcription in generating pathology reports.

CONTEXT: Software that can convert spoken words into written text has been available since the early 1980s. Early continuous speech systems were developed in 1994, with the latest commercially available editions having a claimed accuracy of up to 98% of speech recognition at natural speech rates. OBJECTIVES: To evaluate the efficacy of one commercially available voice-recognition software system with pathology vocabulary in generating pathology reports and to compare this with human transcription. To draw cost analysis conclusions regarding human versus computer-based transcription. DESIGN: Two hundred six routine pathology reports from the surgical pathology material handled at St Joseph's Healthcare, Hamilton, Ontario, were generated simultaneously using computer-based transcription and human transcription. The following hardware and software were used: a desktop 450-MHz Intel Pentium III processor with 192 MB of RAM, a speech-quality sound card (Sound Blaster), noise-canceling headset microphone, and IBM ViaVoice Pro version 8 with pathology vocabulary support (Voice Automated, Huntington Beach, Calif). The cost of the hardware and software used was approximately Can 2250 dollars. RESULTS: A total of 23 458 words were transcribed using both methods with a mean of 114 words per report. The mean accuracy rate was 93.6% (range, 87.4%-96%) using the computer software, compared to a mean accuracy of 99.6% (range, 99.4%-99.8%) for human transcription (P <.001). Time needed to edit documents by the primary evaluator (M.A.) using the computer was on average twice that needed for editing the documents produced by human transcriptionists (range, 1.4-3.5 times). The extra time needed to edit documents was 67 minutes per week (13 minutes per day). CONCLUSIONS: Computer-based continuous speech-recognition systems in pathology can be successfully used in pathology practice even during the handling of gross pathology specimens. The relatively low accuracy rate of this voice-recognition software with resultant increased editing burden on pathologists may not encourage its application on a wide scale in pathology departments with sufficient human transcription services, despite significant potential financial savings. However, computer-based transcription represents an attractive and relatively inexpensive alternative to human transcription in departments where there is a shortage of transcription services, and will no doubt become more commonly used in pathology departments in the future.

Contribution of electron microscopy to understanding cellular differentiation in mesenchymal tumors of the gastrointestinal tract: a study of 82 tumors.

Eighty-two mesenchymal tumors of the gastrointestinal tract were examined by electron microscopy for the purposes of subtyping for diagnostic precision and of understanding cellular differentiation. Tumors were subclassified into leiomyoma/leiomyosarcoma, tumors of the interstitial cell of Cajal (equivalent to traditionally defined GISTs [Miettinen et al. Hum Pathol. 1999; 30:1213-1220; Mod Pathol. 2000; 13:1134-1142]), gastrointestinal autonomic nerve tumors (GANTs), and fibroblastic and myofibroblastic tumors, using criteria from the literature. Leiomyoma/leiomyosarcoma were diagnosed by myofilaments, attachment plaques, plasmalemmal caveolae, and lamina; GIST by processes or cell bodies full of intermediate filaments, solitary focal densities amid intermediate filaments, attachment plaques with incomplete lamina, scarce myofilaments, and smooth endoplasmic reticulum; GANTs by neuroendocrine granules, cell bodies/processes full of intermediate filaments (more rarely microtubules), and smooth endoplasmic reticulum; fibroblastic/myofibroblastic tumors by abundant rough endoplasmic reticulum, myofilaments, and fibronexuses. Seventy-three tumors (89%) were successfully subclassified, as 5 leiomyoma/leiomyosarcoma (6%), 36 GISTs (44%), 22 GANTs (27%), 10 fibroblastic and myofibroblastic tumors (12%). Results indicated overlap between poorly differentiated leiomyosarcoma and GIST, and between GIST and GANT. GANT is emphasized as a neuronal tumor identifiable by electron microscopy, and thereby distinguishable from GIST.