Mohamed Rizwan Haroon Al Rasheed

A Rare Case of Sarcina ventriculi of the Stomach in an Asymptomatic Patient.

Sarcina ventriculi is a gram-positive coccus that grows in a tetrad arrangement in the stomach. In the past 35 years, less than 20 cases have been reported in the literature, and it has been associated with life-threatening complications such as emphysematous gastritis and perforation. Treatment of S ventriculi generally consists of proton pump inhibitors with or without adjuvant antibiotic therapy. We report the first ever case of S ventriculi, including the morphological and immunohistochemical features, occurring in an asymptomatic patient with a history of Helicobacter pylori gastric ulcers.

Encapsulated follicular variant of papillary thyroid carcinoma/noninvasive follicular thyroid neoplasm with papillary-like nuclear features with Spindle Cell Metaplasia: Case report and review of literature

Spindle cell lesions of the thyroid are rare overall, and span a wide clinical spectrum that ranges from spindle cell metaplasia (SCM1) to anaplastic carcinoma. Their differentiation is only seldom straightforward, and usually requires the integration of the clinical, histological and immunohistochemical data. Only a handful of publications have described cases of SCM in the thyroid and we add to that literature by reporting a unique case of encapsulated follicular variant of papillary thyroid carcinoma/noninvasive follicular thyroid neoplasm with papillary-like nuclear features with SCM. In addition, we review the literature on the relationship between SCM and different thyroid lesions, summarizing the morphological and immunohistochemical features that aid in its differentiation from more aggressive spindle cell proliferations.

Tumor necrosis in radical prostatectomies with high-grade prostate cancer is associated with multiple poor prognostic features and a high prevalence of residual disease

The Gleason grading system and the recently defined Grade Groups are strong, well-established predictors of outcome in prostate cancer. Each Gleason score, however, is the result of a sum of categories (Gleason patterns or GPs) that are intrinsically heterogeneous, as each individual pattern encompasses several tumor morphologies. Although the prognostic value of specific morphologic components of GP4 has recently been demonstrated, the significance of the different patterns of GP5 is largely unknown. We reviewed 344 consecutive prostatectomies performed at the Hospital of the University of Illinois at Chicago between 2011 and 2016 and selected 56 cases with primary or secondary GP5 with archival material available for review. Subsequently, we sorted the cases according to the presence or absence of tumor necrosis in invasive adenocarcinoma GP5-designated G5 (+N) and G5 (-N), respectively-for comparison of histopathologic and clinical characteristics. The GP5 (+N) group demonstrated higher prevalence of biochemical recurrence (P=.0006) and seminal vesicle invasion (P=.02), with a trend toward a higher frequency of lymph node metastases (P=.07) and multifocal surgical margin involvement (P=.09). Also, G5 (+N) patients showed higher preoperative prostate-specific antigen values (P=.005) and a larger percentage of submitted tissue involved by tumor (P<.0001). Our results show that GP5 with tumor necrosis is associated with poor prognostic histopathologic features and high rates of residual disease after prostatectomy.

Comparison of prostatic adenocarcinoma Gleason 5 and intraductal carcinoma of the prostate with tumor necrosis. A morphometric study

Intraductal carcinoma of the prostate(IDCP) is defined as a solid or cribriform neoplastic growth confined to ducts and acini, with preservation of the basal cell layer. Since IDCP can often present tumor necrosis (TN), it should be distinguished from Gleason 5 (GP5) invasive adenocarcinoma for staging and clinical purposes. In the present study we reviewed 344 radical prostatectomies performed at our institution and selected all cases with either >5% GP5 or IDCP for assessment of TN on histology slides (n = 59). A total of 19 cases with TN were identified, and morphology, size, location, and histoarchitecture of the lesions with TN were recorded. Subsequently, the corresponding sections were stained with a basal cell immunomarker (P63), and lesions with TN were assigned to IDCP or invasive carcinoma GP5 for comparison. Our results show that a branched shape and size 501-1000 μm are more common in IDCP, while a size >1000 μm and location within 1 mm of the periprostatic soft tissue are significantly more prevalent in invasive adenocarcinoma GP5. These features, however, usually cannot be assessed in core biopsies. In this setting, the utilization of immunohistochemistry is warranted to differentiate IDCP and GP5 with necrosis.

The Role of Next Generation Sequencing in the Differential Diagnosis of Composite Neoplasms

Composite neoplasms (CNs) are rare and diagnostically challenging lesions that require differentiating between mixed clonal tumors with divergent phenotypes (MT), collision of 2 independent tumors adjacent to each other (CT), and tumor-to-tumor metastasis (TTM). To that end, pathologists have traditionally used immunohistochemistry and limited molecular studies, such as Sanger sequencing. Herein we evaluate the potential application of NGS in the differential diagnosis of these rare neoplasms. Four CNs were included in the study. Two were diagnosed as MT (mixed adenoneuroendocrine carcinoma of the gallbladder and metastatic papillary thyroid carcinoma with squamous dedifferentiation) and 2 were interpreted as TTM (esophageal adenocarcinoma to lung adenocarcinoma and small cell carcinoma of the lung to meningeal melanoma). Diagnoses were made using clinical, histologic, and immunophenotypic information, with the aid of limited molecular studies in 2 cases. Formalin-fixed, paraffin-embedded tissue was dissected for DNA and RNA extraction, and NGS was performed using the Oncomine Comprehensive Panel. The 2 tumors initially interpreted as MT showed shared genetic aberrations in the different neoplastic components, supporting the pathologic diagnosis. NGS results for the lesion diagnosed as esophageal adenocarcinoma metastatic to lung adenocarcinoma did not support the histopathologic interpretation and were deemed inconclusive. However, the identification of an identical CDKN2A mutation in all components and in the adjacent benign lung parenchyma suggests a possible germline aberration. Sequencing results in the last case were clearly supportive of TTM. This study illustrates the role of NGS in the diagnostic workup of CNs, as an adjunct to light microscopy and immunohistochemistry.

Succinate Dehydrogenase Complex

Succinate dehydrogenase (SDH) is uniquely tasked with a dual role in the essential energy-producing processes of a cell. Although SDH subunits and assembly factors form part of the same enzyme complex, mutations in their respective genes lead to significantly different clinical phenotypes. Remarkable discoveries in the last 17 years have led to the delineation of the SDH complex deficiency syndrome and its multiple pathogenic branches. Here we provide an updated overview of SDH deficiency in order to raise awareness of its multiple connotations including nonneoplastic associations and pertinent features of the continually growing list of SDH-mutant tumors so as to better direct genetic counseling and predict prognosis.

Sebaceous carcinoma of the breast in a patient with a pathogenic BRCA2 (886delGT) mutation - focus on histopathologic and immunohistochemical features

Sebaceous carcinoma of the breast (SCB) is a rare variant of ductal carcinoma arising within the mammary gland and containing at least 50% of malignant cells with sebaceous differentiation. Only 11 cases that adjust to the criteria delineated in the WHO classification have been published in the English literature, to the best of our knowledge. Here, we present the first SCB arising in the context of a deleterious BRCA2 mutation, focusing on the histopathologic and immunohistochemical features of this exceedingly rare tumor.

156 A Unique Case of Castleman Disease Involving a Retroperitoneal Accessory Spleen

Introduction: Castleman disease is a lymphoproliferative process first described by Dr Benjamin Castleman in 1956. It has been reported to occur in various sites; however, accessory splenic involvement has only been reported once before. Clinically, it is divided into a solitary and a multicentric form. About 90% of the solitary forms are of the hyaline-vascular type, which shows enlarged follicles with tight concentric layering of lymphocytes, vascular proliferation within the follicles with central perivascular hyalinization. The interfollicular parenchymal usually shows prominent vascular proliferation admixed with a mixed inflammatory cell population. Our aim is to report a unique case of unicentric hyaline-vascular type Castleman disease involving a retroperitoneal accessory spleen that presented in an otherwise healthy woman. Method: This is a retrospective review of a case of a 32-year-old woman who presented with a retroperitoneal mass incidentally discovered on an abdominal ultrasound. Results: Radiographic studies showed a 6 cm contrast enhancing mass posterior to the pancreas clinically suspicious for malignancy. Fine needle aspirations failed to provide diagnostic material and the mass was surgically excised. The specimen showed a mixture of red and white pulp typical of splenic tissue. Enlarged follicles with concentric tight layering of small lymphocytes surrounding hyalinized central small blood vessels were present, as well as increased red pulp vascularity. Flow cytometry showed no evidence of a monoclonal lymphoid population. The findings were diagnostic of hyaline vascular type Castleman disease occurring in accessory splenic tissue. Conclusion: Unicentric Castleman disease usually acts in a benign fashion but can present in a variety of unusual sites including accessory splenic tissue and can be clinically confused with malignancy. Excisional biopsy is the procedure of choice for accurate diagnosis.

Angiosarcoma of the hand associated with pseudoaneurysm

Angiosarcoma is a rare malignancy of vascular endothelial origin. We describe a case of angiosarcoma of the hand initially histopathologically diagnosed as a pseudoaneurysm, emphasizing the diagnostic importance of radiological pathologic concordance. Here we highlight the distinctive imaging and the histopathologic features of angiosarcoma, invaluable to its accurate and timely diagnosis.

Sarcoidosis in an Endometrial Polyp

Endometrial sarcoidosis is one of the rarest forms of extrapulmonary sarcoidosis, with less than 35 cases ever being reported in the English medical literature. Furthermore, uterine sarcoidosis coexisting with an endometrial polyp has never been previously reported. A 60-year-old postmenopausal Hispanic woman presented complaining of intermittent pelvic pain. Her past medical history was notable for an incidental computed tomography (CT) scan finding of 2 noncalcified pulmonary nodules about 4 years prior. A repeat CT scan 3 months later revealed calcified mediastinal and left hilar lymph nodes, with no focal pulmonary nodules, and a third CT scan 3.5 years later reidentified the pulmonary nodules without increase in size and stable calcified mediastinal and left hilar lymph nodes. A pelvic ultrasound to evaluate her current pelvic pain revealed an uterine fibroid and thickened endometrial stripe measuring 8.7 mm with increased vascularity. Given the findings, a hysteroscopy and endometrial curetting was performed. During the procedure, a firm-appearing polypoid structure was identified attached to the uterine fundus, which was resected and submitted to pathology along with the endometrial curetting. Microscopic examination revealed a polypoid structure (Figure 1) containing large thick-walled vessels and surrounded by cystically dilated weakly proliferative endometrial glands (Figure 2). Embedded in the benign appearing endometrial stroma were multiple noncaseating granulomas composed of lymphocytes, epithelioid macrophages, and multinucleated giant cells (Figure 3). Within the cytoplasm of some of these multinucleated cells were polarizable colorless crystalline inclusions, occasionally with foci of early Schaumann (conchoidal) bodies forming around them (Figure 4). Ziehl-Neelsen stain was negative for mycobacteria, and Gomori methenamine silver stain was negative for fungal organisms. These histological findings are compatible with an endometrial polyp involved by sarcoidosis. Endometrial involvement by sarcoidosis is commonly associated with concurrent involvement of other organs, such as eyes and lungs. Rarely though, endometrial sarcoidosis may present as a polypoid lesion as a result of the endometrial sarcoid granulomas rather than a true histologic endometrial polyp. Colorless birefringent crystals or inclusions have long been identified in sarcoid granulomas. They consist predominantly of calcium oxalate, originate in the macrophages, and are precursors to other 673908 IJSXXX10.1177/1066896916673908International Journal of Surgical PathologyHaroon Al Rasheed et al research-article2016