bluuebunny/crossref_metadata_2025_split huggingface dataset:
Colonic Large Cell Neuroendocrine Carcinoma with Extensive Carcinomatosis: A Highly Aggressive Tumor
Authors: Bhatt M , Al-Khafaji B 
Published: October 2021

Abstract

Introduction/Objective
Large cell neuroendocrine carcinoma (LCNEC) of the colon is an exceedingly rare and aggressive neuroendocrine carcinoma. These tumors are associated with a poor prognosis, as they are commonly diagnosed in advanced stages with distant metastases. We present a case of a patient with colonic LCNEC with carcinomatosis peritonei who underwent surgical resection and hyperthermic intraperitoneal chemotherapy.

Methods/Case Report
The patient is a 49-year-old Caucasian male who presented with several months history of occasional hematochezia, constipation, 40-pound unintentional weight loss, and reflux. An initial diagnosis of adenocarcinoma of colorectal origin was rendered. Subsequently, the patient underwent a low-anterior resection with hyperthermic intraperitoneal chemotherapy (HIPEC). Histological evaluation of the rectosigmoid lesion demonstrated sheets of malignant epithelial cells with scant amphophilic cytoplasm, large pleomorphic vesicular nuclei, prominent nucleoli, and numerous mitotic figures. The tumor invaded the entire colonic wall and extended to the visceral peritoneum with extensive small vessel lymphovascular and perineural invasion with widespread involvement of the diaphragm, spleen, falciform ligament, and omentum. Immunohistochemical stains showed the tumor to be diffusely positive for CK20, CDX2, and synaptophysin; while negative for CK7, PAP, PSA, chromogranin, and p40. These findings are consistent with the diagnosis of a large cell neuroendocrine carcinoma. In addition, CD31 highlighted lymphatic spaces that were extensively filled with tumor cells. One-month post-operative, the patient remains in critical but stable condition with features of acute hypoxic respiratory failure and possible metastatic disease to the lung associated with pleural effusion.

Results (if a Case Study enter NA)
NA

Conclusion
Colonic large cell neuroendocrine carcinoma (LCNEC) is a rare, highly aggressive neuroendocrine carcinoma that frequently presents with distant metastases. Clinical awareness of the entity with early diagnosis and surgical resection remains the essential initial step. Utilizing immunohistochemistry stains to further characterize the tumor is critical to reach the correct diagnosis. Accumulating appropriate clinical data will aid in the establishment of future treatment protocols.
Squamous Metaplasia in Colonic Tubulovillous Adenoma: A Three Case Series and review of literature
Authors: Duhoki D , Allison D , Wiley E 
Published: October 2021

Abstract

Introduction/Objective
Although squamous metaplasia of colonic tubulovillous adenoma is a rare phenomenon, colorectal polyps can show focal squamous metaplasia. While the exact cause in unknown, it has been suggested that mechanical irritation, torsion and chronic inflammation may predispose to squamous metaplasia within large colonic polyps.

Methods/Case Report
We observed this finding in two men and one woman with colorectal polyps who underwent endoscopic mucosal resection in a three-week timeframe. In two cases the polyps were rectal, while in the third case, it was located in the descending colon. Polyp size ranged from 1-5 cm and were semi-pedunculated. Histologically, all three lesions were tubulovillous adenomas with focal high-grade dysplasia and multiple foci of squamous metaplasia characterized by cells with benign-appearing nuclei, eosinophilic cytoplasm, and solid growth pattern. Some metaplastic foci approached the muscularis mucosae, mimicking adenocarcinoma at low power magnification. Interestingly, these metaplastic foci were reactive against p16 immunohistochemical stain.

Results (if a Case Study enter NA)
NA

Conclusion
We present these three cases to add to the few previously reported. Pathologists should be aware of this finding to avoid the overdiagnosis of invasive carcinoma in the setting of nested and pseudo invasive squamous morules, especially in polyps with high grade dysplasia. In addition, squamous metaplasia could be a precursor lesion for colorectal squamous cell carcinoma.
Synchronous Schwannoma and Gastrointestinal Stromal Tumor in Small Intestine – A Rare Case
Authors: Mohammed S , Sadiq Q , Yadak N , Khan F 
Published: October 2021

Abstract

Introduction/Objective
Small bowel Schwannoma is a benign neoplasm of nerve sheath cells. The Gastrointestinal stromal tumor (GIST) constitutes only about 1-2% of small bowel spindle cell tumors. The simultaneous presence of two tumors in the small bowel is extremely uncommon.

Methods/Case Report
We report a case of small bowel GIST co-existing with Schwannoma. A 64-year-old female with a known history of Neurofibromatosis was admitted for excision of a small bowel tumor. MRI of the abdomen revealed two enhancing lesions in the left upper quadrant adjacent to the small bowel. Differential considerations included GIST versus Neurofibroma. Left hemicolectomy with small bowel resection was performed. The proximal small bowel revealed GIST, spindle cell type, low risk (3.5 cm), low grade (&lt;5 mitoses/ 5mm2). Tumor cells were diffusely reactive to CD34, CD117, and DOG1 immunostains and were nonreactive to S100 and SOX10 immunostains confirming the diagnosis of GIST. Another segment of the small bowel revealed a 1.5 cm well-circumscribed, predominantly spindle cell tumor with abundant myxoid stroma and prominent cyst formation. Tumor cells were diffusely reactive to S100 and SOX10 immunostains but nonreactive to CD34, CD117, and DOG1, favoring a diagnosis of Schwannoma. Gastrointestinal Schwannomas may be associated with Neurofibromatosis in some cases. GIST, a KIT- or PGDFRA-signaling driven mesenchymal tumor has also rarely been reported to be associated with Neurofibromatosis type 1. However, synchronous small bowel Schwannoma and GIST represent a rare co-existence of two different histopathologic subtypes of spindle cell tumors.

Results (if a Case Study enter NA)
NA

Conclusion
In summary, we present the rare co-existence of two different spindle cell lesions in Neurofibromatosis patient.
Gastric marginal zone lymphoma of mucosa-associated tissue and Epstein-Barr Virus associated lymphoepithelioma gastric carcinoma: Two primaries with an unusual metachronous presentation
Authors: Gallardo J , Mahadik J , Finch C J , Szigeti R , Shilpa J 
Published: October 2021

Abstract

Introduction/Objective
Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) and Epstein-Barr virus (EBV) lymphoepithelioma gastric carcinoma, are two distinct gastric malignancies, with well-known clinicopathological characteristics. Synchronous or metachronous presentation of both entities in the same patient is extremely rare.

Methods/Case Report
We report a case of a 78-year-old woman, who presented with a 3 cm gastric body mass. Histologically, the biopsy showed H. pylori gastritis, with diffuse monotonous atypical lymphocytic cells and prominent lymphoepithelial lesions. CD20 immunostain was diffusely positive in these cells, supporting the diagnosis of MALT lymphoma. The patient was treated for H. pylorieradication, followed by Rituxan for resistant MALT lymphoma found in a surveillance biopsy. After being free of disease for one year, the patient developed a 2.0 cm, ulcerated lesion adjacent to the previous site. Biopsy of this lesion showed gastric mucosa with diffuse lymphoepithelial lesions, and atypical epithelial cells highlighted by pan-cytokeratin. The associated dense inflammatory infiltrate was comprised predominantly of CD3 T-lymphocytes. EBV was detected by in-situ hybridization (ISH) for EBV encoded RNA, and was positive in the epithelial cells, but negative in lymphocytes. These findings are consistent with EBV associated lymphoepithelioma carcinoma.

Results (if a Case Study enter NA)
NA

Conclusion
This case is presented due to its rarity, with only two cases reported previously, which invokes further research into the interaction between both infectious agents. Secondly, lymphoepithelial lesions are a common finding in both diseases, and in small biopsies, these entities can mask or mimic each other. EBV ISH and background B and T lymphocytes may be a clue and help in the diagnosis.
Small Bowel Obstruction as a Rare Complication of Progressive Sclerosing Mesenteritis
Authors: Karimi S S , Hassan M , Mehta V 
Published: October 2021

Abstract

Introduction/Objective
Sclerosing Mesenteritis is an uncommon, idiopathic, localized inflammatory syndrome involving the small intestine and colonic mesentery. It is considered a benign condition that commonly occurs in elderly with a gender predilection for males, and its etiology remains unknown. Small Bowel Obstruction (SBO) is a rare, unexpected, but detrimental complication of progressive Sclerosing Mesenteritis. Herein, we present a case of an enlarging, progressive Sclerosing Mesenteritis with extensive involvement of the small bowel and mesentery requiring two consecutive major surgical interventions.

Methods/Case Report
A 72-year-old male with Myelodysplastic Syndrome (MDS) and recent history of loop ileostomy due to distal intestinal obstruction secondary to enlarging Sclerosing Mesenteritis, presented to our institution with non-specific symptoms of worsening abdominal pain and multiple episodes of gastrointestinal bleeding. Radiographic investigation revealed SBO and he subsequently underwent exploratory laparotomy resulting in total enterectomy with excision of mesenteric mass, extended right colectomy, Whipple procedure, and gastrostomy. The specimens were sent to pathology for histopathological evaluation and gross examination revealed several bosselated, tan-white, firm and rubbery, fibrotic lesions with associated lobulated fibroadipose tissue. Microscopic examination showed extensive mesenteric fibrosis with dense bundles of collagen fibers, areas of fat necrosis, mucosal ischemia and calcification involving the small bowel and serosal surface of large intestine and peritoneum. The lesional cells showed minimal atypia, mitoses, and lacked the Beta-catenin nuclear staining seen in mesenteric fibromatosis. Given the clinical history and histopathological findings of the lesion, we favored the diagnosis of Sclerosing Mesenteritis.

Results (if a Case Study enter NA)
N/A

Conclusion
The etiology of Sclerosing Mesenteritis is not well-understood and there are cases of Sclerosing Mesenteritis reported in the literature in association with trauma, surgery, malignancy, and IgG4-related disease. Our patient’s post-operative history was complicated by short gut syndrome, and he is currently requiring small bowel transplant. We report this case for its unusual and aggressive clinical presentation, and to heighten clinical awareness for detrimental consequences of this seemingly benign condition.
A Rare Medullary Carcinoma of Jejunum
Authors: Fathima S , Bredeweg A 
Published: October 2021

Abstract

Introduction/Objective
Medullary carcinoma of jejunum is an extremely rare condition. These tumors account for less than 0.04% of all colorectal cancers and less than 3 cases to date has been reported in the small intestine

Methods/Case Report
We present a case of 78-year-old woman with a celiac disease and collagenous colitis, chronic diarrhea, chronic anemia and 2.1 cm apple core lesion on mid to distal jejunum on CT leading to partial obstruction.

Results (if a Case Study enter NA)
Histologically tumor showed invasive carcinoma in a solid growth pattern with pushing border. The tumor cells were uniform, enlarged with prominent nucleoli and brisk mitotic activity. There was prominent inflammatory response within and around the tumor. Immunohistochemical stains were positive for CK7, CDX2 CK19, CKAE1-3 and negative for CD45, CK20, Chromogranin Synaptophysin, PAX-8. MLH1 &PMS2 showed loss of nuclear expression and MSH2 & MSH6 with Intact nuclear expression. Microsatellite instability was High (MSI- H) with instability in two or more microsatellite markers. Diagnosis of medullary carcinoma of jejunum was made.

Conclusion
Although the clinical manifestations can be consistent with signs of intestinal obstruction, often these rare tumors are discovered incidentally. Conditions such as celiac disease, Crohn’s disease, and other chronic inflammatory illnesses have been linked to contributing risk factors. Imaging and appropriate tumor markers have less role in diagnosis; however, biopsy is needed for definitive diagnosis. Even though the development of these tumors in the small bowel is rare, further enhancement of awareness can aid in the appropriate early detection and appropriate treatment modalities.
A case of osseous metaplasia in a gastric hyperplastic polyp: An unexpected finding in a common polyp
Authors: Zhang Y , Nakanishi Y 
Published: October 2021

Abstract

Introduction/Objective
Foveolar hyperplastic polyp is a common gastric polyp characterized by foveolar hyperplasia with erosion, acute and chronic inflammation, granulation tissue formation, and smooth muscle strands extending from the muscularis mucosae. Although foveolar hyperplastic polyps may rarely contain foci of dysplasia or invasive carcinoma, osseous metaplasia/heterotopic bone formation in foveolar hyperplastic polyps of the stomach is extremely rare with a few case reports.

Methods/Case Report
A 63-year-old female with a history of hypertension, sick sinus syndrome, and Hashimoto’s thyroiditis was referred to our facility for evaluation of a mass in segment eight of the liver. The liver biopsy showed a moderately differentiated adenocarcinoma, most consistent with intrahepatic cholangiocarcinoma. A screening gastrointestinal endoscopy revealed a 7-mm sessile polyp in the antrum. The polyp was removed with a cold snare. No other abnormalities were identified in the stomach. Sections of the polyp showed fragments of antral-type gastric mucosa with foveolar hyperplasia, erosion, acute and chronic inflammation, and focal granulation tissue formation. In addition, multiple foci of woven bone formation without bone marrow surrounding dilated gastric foveolae were identified. No Helicobacter infection, intestinal metaplasia, dysplasia or malignancy was identified histologically. Osseous metaplasia/heterotopic bone formation is a well-known finding reported in various neoplastic and non- neoplastic conditions. However, osseous metaplasia in foveolar hyperplastic polyps of the stomach is extremely rare. There have been only four previous case reports published in English language. Our current case shows clinicopathologic features similar to those of the previous case reports including the findings of small-sized polyp found incidentally in middle-aged patients with no clinical history of hypercalcemia or any other abnormalities causing heterotopic bone formation.

Results (if a Case Study enter NA)
N/A

Conclusion
Although the pathogenesis of osseous metaplasia in a gastric hyperplastic polyp remains unknown, the finding of osseous metaplasia in a gastric hyperplastic polyp is very intriguing.
Use of Elastic Stain Technique to Detect Histologically Occult Vascular Invasion in Resected Colorectal Carcinomas at Danbury Hospital
Authors: Karki S , Steven S , Kaur G , Das D , Agarwal R 
Published: October 2021

Abstract

Introduction/Objective
Colorectal carcinoma (CRC) represents a leading cause of cancer related death in the western world and is by far the most common malignancy of the gastrointestinal tract. Vascular invasion (VI), in particular extramural VI by tumor is recognized as a feature of colorectal cancer progression, and the latter is an independent prognostic indicator of disease recurrence and survival in colorectal carcinoma. The purpose of this study is to detect VI in resected colorectal tumor samples and compare sensitivity of elastic staining to routine H&E staining at Danbury Hospital.

Methods/Case Report
A total of 50 colorectal cancer specimens from segmental colon resection or endoscopic polypectomy performed at Danbury Hospital over a 3-year period were included. Histologic sections of each tumor were assessed for the presence of VI by routine H&E staining. Superficial recuts of each tumor were subjected to elastic Von Giesen staining and reassessed for the presence of vascular invasion. Sensitivity of routine H&E staining for the detection of VI was calculated with elastic stain serving as the “gold standard”.

Results (if a Case Study enter NA)
In this study, VI by carcinoma was identified by H&E stain and/or elastic stain in 17 (34%) out of 50 cases. H&E stain and elastic stain detected VI in 12 (24%) and 16 (32%) out of 50 cases, respectively. There was a single case for which H&E stain showed vascular invasion that was not confirmed by elastic stain, representing a false negative for the H&E technique. Elastic staining detected VI in 5 cases for which the corresponding H&E stain was falsely negative for VI. Overall, vascular invasion status (absent or present) was concordant in 44 (88 %) of the 50 cases. With elastic stain deemed the “gold standard” for VI detection, the sensitivity, specificity, negative predictive value, and positive predictive value of H&E stain were found to be 68.7%, 97.0%, 86.8%, and 91.6%, respectively.

Conclusion
Although H & E staining of colorectal carcinoma tissue sections have a very good specificity and positive predictive value for the detection of VI, this technique suffers from a suboptimal sensitivity. For these reasons, we agree with previously published literature reports that the use of elastic stain as a supplement to H & E staining should be strongly considered for the proper evaluation and prognostication of colorectal carcinoma specimens.
Expression of Estrogen and Progesterone Receptors in a Tailgut Cyst with Carcinoid Tumor
Authors: Mohamed N , Rampisela D , Lopez L M 
Published: October 2021

Abstract

Introduction/Objective
Tailgut cysts (TC) are congenital lesions that arise in the presacral space. They originate from the embryonic hindgut and usually present between the ages of 30-60, with female predominance. TCs are usually asymptomatic or can present with lower back, perianal or pelvic pain. Malignant transformation of a TC is a rare complication, with adenocarcinoma being the most common, followed by carcinoid tumor. About thirty cases of carcinoid tumors arising in a TC have been reported in the literature so far with a slight female predominance (1.5:1).

Methods/Case Report
We describe a 40-year-old Hispanic woman with a 9-year history of cyclic pelvic pain related to her menstrual cycles. She was diagnosed with adenomyosis and underwent hysterectomy that did not completely resolve her symptoms. Follow-up serial imaging showed a growing complex-cystic presacral mass, which was eventually excised. Grossly, there was a 3.6×3.1×2.5 cm multiloculated cystic mass filled with mucoid material. Microscopically, there were multiple cystic spaces lined by benign squamous and mucinous columnar epithelium and surrounded by smooth muscle cells. A 6-mm carcinoid tumor was found within a cyst wall and confirmed by positive synaptophysin and chromogranin staining with a Ki-67 proliferation index of &lt;2%. Estrogen and progesterone receptor immunostains were positive in the epithelial cyst linings and the stromal cells but not in the carcinoid tumor cells.

Results (if a Case Study enter NA)
NA

Conclusion
We conclude that the diagnosis of TC should be considered in the differential of gynecologic patients with unresolved cyclic pelvic pain and that estrogen and progesterone could have an important role in the pathogenesis of TCs. Furthermore, estrogen receptors can be a therapeutic target in patients with this entity.
Adenoid basal carcinoma with adenoid cystic-like features—a rare diagnostic dilemma
Authors: Salahi N , Jabbar A , Lavitan D 
Published: October 2021

Abstract

Introduction/Objective
Adenoid basal carcinoma (ABC) of the cervix is a rare, indolent tumor with no known metastatic potential. The tumor is composed of small nests of bland, basaloid cells, which do not elicit a desmoplastic response within the surrounding stroma. Cystic and clear cell change, as well as glandular differentiation, are not unusual. As such, it is important to differentiate ABC from adenoid cystic carcinoma (ACC), particularly on account of the aggressive clinical course of the latter. We herein present a rare case of ABC with adenoid cystic-like features.

Methods/Case Report
A 74-year-old woman with an incidental ABC, diagnosed on an excisional procedure performed for a prior diagnosis of a high grade squamous intraepithelial lesion. Subsequent hysterectomy revealed a tumor composed of nests of basaloid cells, extending into the outer third of the cervical wall, but exhibiting no peri- tumoral desmoplasia. Cribriforming associated with increased mitotic activity was focally present and showed increased Ki-67 labeling compared to the solid nests of tumor. PAS special stain highlighted rare pseudolumina with basement membrane-like material. While these features were concerning for an ACC—the lack of any significant cytologic atypia, destructive stromal invasion, and a clinically apparent lesion—was consistent with an ABC with so- called adenoid cystic-like features.

Results (if a Case Study enter NA)
NA

Conclusion
Making an accurate diagnosis requires clinicopathologic correlation and awareness of histologic overlap. Additionally, adenoid cystic-like morphology in ABCs is a little-studied phenomenon, which necessitates further research to shed light on potential clinical implications.
Heterotopic Sex Cord-Stromal Proliferation: A Case Report
Authors: Lagerstrom I , Uy M , Teschan N 
Published: October 2021

Abstract

Introduction/Objective
Sex cord-stromal cells at extraovarian sites are extremely rare and due to the low number of cases reported, the true incidence is unknown. We present the case of a patient with symptomatic uterine fibromas that had a benign extraovarian heterotopic sex cord-stromal proliferation.

Methods/Case Report
A 44-year-old female presented with pelvic pressure and discomfort. Past medical history is significant for breast cancer treated with bilateral mastectomy in 2019 followed by radiation treatments. The patient had no menses since January 2020 but had begun noticing spotting prior to the onset of her pelvic pressure and discomfort. Pelvic ultrasound revealed an enlarged uterus consistent with fibroids and a right adnexal mass. Endometrial biopsy following the ultrasound was normal. The patient desired definitive treatment and a total abdominal hysterectomy and bilateral salpingo-oophorectomy was subsequently performed. Gross examination of the surgical specimen revealed a fibroid uterus and normal appearing bilateral ovaries and fimbriated fallopian tubes. Histopathology showed a uterus with leiomyomata and serous cystadenofibromas in bilateral ovaries. The left fallopian tube fimbria showed a well-circumscribed proliferation of pale, ovoid cells in a microfollicular pattern. Rare cells with grooved nuclei were present. No significant atypia and no mitotic activity were identified. Immunohistochemical staining was positive for inhibin, WT-1, and vimentin. Negative stains include EMA, GATA-3, GCDFP 15, mammaglobin, chromogranin, and calretinin. Final diagnosis was determined to be benign fallopian tube with heterotopic sex cord-stromal proliferation.

Results (if a Case Study enter NA)
NA

Conclusion
This case highlights a rare, incidental finding. These lesions are postulated to represent non-neoplastic embryologic remnants. However, most heterotopic sex cord-stromal proliferations are found in fimbriae, which could suggest that they arise from heterotopic ovarian tissue exposed during ovulation. The incidence of these benign proliferations is expected to increase as routine sampling of adnexal structures is becoming more commonplace, which presents diagnostic challenges for pathologists.