Histiocytic sarcoma arising from a lymph node: a diagnostic conundrum.

Histiocytic Sarcoma (HS) is extremely rare, with only a few hundred cases reported in the literature. The majority of patients present with symptoms due to unifocal or multifocal extra-nodal disease. Less than 20% of these cases show solitary involvement of a lymph node. We report a case of a solitary HS in a 53-year-old woman presenting with a 2.7-cm right groin mass arising from an inguinal lymph node. The initial cytologic examination of the tissue showed a high-grade spindle-shaped morphology with high-grade mitotic activity. A high-grade sarcoma was initially considered considering the absence of normal lymphoid aggregate and the presence of high-grade cytologic features in the cells. To evaluate the tumor in its entirety, the mass was surgically excised. A histological examination of the tumor showed focal rimming of the lymphoid tissue at the periphery and a centrally located stellate necrotic focus. The tumor cells had an epithelioid to spindle cell morphology along with large uniform nuclei and prominent nucleoli. A high mitotic index was present. Immunohistochemistry (IHC) stains showed strong positivity for CD68, CD163, and Vimentin, and were weakly positive for SMA and CD45. Based on the histologic and clinical examination, a diagnosis of HS was made. Multiple malignancies can mimic HS histopathology and the rarity of this tumor makes the diagnosis more challenging. No fine-needle aspiration (FNA) criteria for its diagnosis have been recognized. Herein, we report a rare case of an isolated HS involving a lymph node which resembled high-grade sarcoma on the FNA biopsy to raise awareness among our surgical pathologist colleagues.

Triple-Negative Metaplastic Breast Carcinoma: Association of Epidermal Growth Factor Receptor Expression With Prognostic Parameters and Clinical Outcome.

Introduction Metaplastic breast carcinoma (MBC) is one of the rare special subtypes of breast carcinoma associated with poor prognostic features compared with invasive ductal carcinoma. Moreover, therapeutic options are limited in MBC owing to frequent triple-negative profiles of these tumors. Epidermal growth factor receptor (EGFR) is a proto-oncogene that is overexpressed in many human cancers, and is a potential therapeutic target. Therefore, in this study, we evaluated the expression of EGFR in MBC by immunohistochemistry, and its association with clinicopathological and prognostic parameters. Methods We conducted a retrospective observational study in the Department of Histopathology at Liaquat National Hospital and Medical College, Pakistan, over a period of seven years. A total of 61 cases with a histopathological diagnosis of MBC were included in the study. All slides were reviewed by histopathologists for diagnostic confirmation. Histopathological parameters, such as tumor size, grade, and nodal metastasis, were recorded. The representative tissue blocks were also retrieved and immunohistochemical studies were performed for cytokeratin 5/6 (CK5/6), Ki67, and EGFR. Results The mean age of the patients was 44.48 ± 13.01 years. The mean tumor size was 5.72 ± 2.72 cm, with most of the cases belonging to tumor (T)-stage T3. Axillary metastasis was present in 57.4% cases, and the perinodal extension was present in 11.5% cases. Most tumors were grade III (85.2%), with a mean Ki67 index of 39.67% ± 20.38%. Most of the cases were nonbasal (83.6%), owing to the absent CK5/6 expression. Tumor recurrence was noted in 14.8% cases, with a median follow-up of 43 (13-83) months and median disease-free survival of 36 (12-60) months. Positive EGFR expression was noted in 52.5% cases. A significant association of EGFR expression was noted with tumor grade, mean Ki67 index, axillary metastasis, and nodal (N)-stage. Cases with positive EGFR expression were found to have higher grade (grade III), with higher Ki67 index, higher frequency of axillary metastasis, and higher N-stage. Moreover, cases with positive EGFR expression had lower disease-free survival compared to cases with negative EGFR expression. Conclusion We found that a significant proportion of triple-negative MBC expressed EGFR. Moreover, EGFR overexpression was associated with poor pathological parameters and lower disease-free survival. Therefore, EGFR can be considered a potential prognostic biomarker and therapeutic target in triple-negative MBC; however, the correlation between gene amplification and protein overexpression is required to better uncover the role of EGFR as a therapeutic target.

Clinicopathological Features of Craniopharyngioma: A 15-Year Study From a Tertiary Care Center in Pakistan.

Introduction Craniopharyngiomas (CPs) are benign neoplasms and most common suprasellar tumors. They are more frequent in children, contributing to a significant number of intracranial tumors in the pediatric population and are thought to be arising either from the epithelial remnant cells of the craniopharyngeal duct or from the adenohypophysis epithelium. Two subtypes of CPs exist, namely, adamantinomatous craniopharyngioma (ACP) and papillary craniopharyngioma (PCP). ACP is more common in children with a relatively aggressive clinical course and more frequent relapses than PCP. The study objective was to evaluate the clinicopathological features of CP in our population. Methods We conducted a retrospective observational study in the Department of Histopathology at Aga Khan Hospital, Karachi, Pakistan, over a period of 15 years, from January 2001 to December 2015. All CP cases were included in the study. A total of 207 cases were diagnosed during this period by histopathologists based on histologic features. All slides were retrieved, and diagnosis was confirmed after a reexamination of slides. Results We found that the mean age of diagnosis was 25.59±14.71 years, and the median follow-up time was 7 (3-19) years. The number of male patients was 136 (65.7%) and the number of female patients was 71 (34.3%). The most common tumor site was suprasellar (71.5%) followed by the sellar and temporal lobe (12.1% and 6.8%, respectively). The most common complaints were headache (21.7%), followed by loss of vision/decreased vision (16.4%) and vomiting (5.3%). The overall survival rate was 95.2% with a recurrence rate of 5.8%. A significant association of survival was noted with tumor recurrence. Conclusion CP is a rare brain tumor with good overall survival. We found a low recurrence rate of CP in our study. However, recurrence was found to be the most important factor determining survival in patients with CP.

Metaplastic Breast Carcinoma: Clinicopathological Parameters and Prognostic Profile.

Introduction Metaplastic breast carcinoma (MBC) is defined as breast cancer with a heterologous non-glandular component. MBC is considered a special type of breast cancer with a prognosis that is worse than invasive ductal carcinoma (IDC) of the breast. MBC is the most common breast cancer with a triple-negative profile. Therefore, in this study, we evaluated the clinicopathological parameters, recurrence and survival of MBC in our population. Methods We conducted a retrospective observational study in the Department of Histopathology at Prince Faisal Oncology Centre, Buraidah, Saudi Arabia, over a period of five years. All cases diagnosed as MBC were included in the study. Estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2/neu) immunohistochemistry (IHC) was performed on representative tissue blocks. Results Total 183 cases of MBCs were included in the study, out of which 120 cases were excision specimens. The mean age of the patients was 48.84±12.99 years, and the most common age group was between 36 and 50 years of age. Most of the cases were tumor (T) stage T3 (50%), and nodal metastasis was present in 40% of cases. Most cases were grade III (78.7%). ER, PR and HER2/neu positivity was noted in 15.8%, 13.1%, and 9.8% cases, respectively. Follow-up data were available for 70 cases, with a median follow-up period of 4 (1-7) years. Tumor recurrence was noted in 31.4% cases, with a survival rate of 71.4%. Squamous, chondroid, spindle cell differentiation, and matrix production were noted in 70.5%, 7.1%, 13.7%, and 2.2% cases, respectively. A significant association of squamous differentiation was noted with HER2/neu positivity. An inverse association of spindle cell differentiation was seen with axillary metastasis. Survival analysis by Kaplan-Meier revealed a significant association of survival with tumor recurrence. Conclusion MBC is an important subtype of breast cancer, histopathological identification of which is challenging, owing to varied histological differentiation. We found squamous differentiation to be the most common in MBC, which was associated with HER2/neu positivity. A high recurrence rate of MBC was also observed in our study that was significantly associated with survival.

Flattening the World of Pathology Education and Training and Shortening the Curve of Pathology Learning.

OBJECTIVES: We review how the pandemic-related education disruption may interplay with pathology manpower worldwide and shifts in disease burden to identify workable solutions. METHODS: Literature related to pathology education, pathology services in low-resource settings, and application of digital tools to pathology education was reviewed for trends and training gaps. Publications covering pathology manpower and cancer incidence worldwide were also included to assess needs. RESULTS: Pandemic-related virtual teaching has produced abundant online training materials. Pathology learning resources in low- to middle-income countries remain considerably constrained and dampen pathology manpower growth to meet current needs. Projected increases in disease burden toward the developing world thus pose a major challenge. Digital pathology resources have expanded and are beginning to appear beyond the developed countries. CONCLUSIONS: This circumstance offers a unique opportunity to leverage digital teaching resources to enhance and equitize training internationally, potentially sufficient to meet the rising wave of noncommunicable diseases. We propose four next steps to take advantage of the current opportunity: curate and organize digital training materials, invest in the digital pathology infrastructure for education and clinical care, expand student exposure to pathology through virtual electives, and develop further competency-based certification pathways.

Mucinous Breast Carcinoma: Clinicopathological Comparison With Invasive Ductal Carcinoma.

Introduction Invasive ductal carcinoma (IDC) is the most common histological subtype of breast cancer. Conversely, many special types of breast carcinoma were described with varying prognosis and hormone receptor status. Mucinous carcinoma (MC) is a rare special subtype of breast cancer, and only a few studies have evaluated the clinicopathological and hormone receptor profile of this type of breast cancer. Therefore, in this study, we compared the clinicopathological characteristics of MC with IDC in our population. Methods A retrospective observational study was conducted in the Department of Histopathology, Liaquat National Hospital and Medical College, from January 2013 till December 2020, for eight years. During this period, 38 cases of MC were diagnosed and 1268 cases of IDC were identified. All specimens were grossed according to standard protocols and representative sections were submitted from tumors, resection margins, and lymph nodes. Slides were examined by histopathologists to determine tumor type and grade. Immunohistochemical (IHC) stains were applied to evaluate estrogen receptor (ER), progesterone receptor (PR), Ki67, and human epidermal growth factor receptor 2 (HER2/neu) statuses. Results The mean age of the patients with MC was 56.47±13.90 years, and most of the patients were above 50 years of age. The mean tumor size was 34.89±19.70 mm. Most tumors were grade 1 (68.4%) with a low mean Ki67 index (15.21±14.06%). Axillary metastasis was present in 31.6% of cases and all of them were nodal (N)-stage N1. ER, PR, and HER2/neu positivity were noted in 94.7%, 78.9, and 10.5% cases, respectively. Compared with IDC, a significant association of MC was noted with age, Ki67 index, tumor (T)-stage, N-stage, and tumor grade. MC cases had a higher mean age than IDC cases. Comparative analysis revealed that MC had a lower frequency of axillary metastasis, a lower mean Ki67 index, and a lower tumor grade than IDC. About biomarker status, MC was noted to have a higher frequency of ER and PR expression, and a lower frequency of HER2/neu expression than IDC. Conclusion MC is a rare subtype of breast cancer. However, it is important to recognize this subtype of breast cancer as it is associated with a prognostically better pathological profile, such as lower tumor grade and Ki67 index, lower frequency of axillary metastasis, higher expression of ER and PR, and lower expression of HER2/neu.

Invasive Papillary Carcinoma of the Breast: Clinicopathological Features and Hormone Receptor Profile.

Introduction Papillary neoplasms are a heterogeneous group of breast lesions, ranging from benign to in situ and invasive malignant tumors. The term invasive papillary carcinoma (IPC) is reserved for rare invasive breast tumors showing greater than 90% papillary morphology. The clinical, epidemiological and pathological characteristics of IPC are not widely described in the existing literature; therefore, in this study, we evaluated the clinicopathological features and biomarker profile of IPC and compared it with invasive ductal carcinoma (IDC) diagnosed in the same study duration. Methods A retrospective study was conducted in the Department of Histopathology, Liaquat National Hospital and Medical College, from January 2013 to December 2020. During the study period, 44 cases of IPC and 1,268 cases of IDC were diagnosed. Slides and blocks of all cases were retrieved and histopathological diagnosis was reviewed. Estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2/neu), and Ki67 immunohistochemical (IHC) stains were applied on representative tissue blocks. Results The mean age of the patients with IPC was 58.77±8.38 years, and the mean Ki67 index was 19.95±21.12%. The mean tumor size was 32.41±17.39 mm, and most tumors (59.1%) were tumor (T)-stage T2. Axillary metastasis was present in 13.6% cases, and 86.4% cases had nodal (N)-stage N0. ER and PR expression was noted in 72.7% cases, and HER2/neu positivity was seen in 13.6% cases. IPC cases had a higher mean age than IDC. Conversely, IPC had a lower mean Ki67 index than IDC. Similarly, IPC cases were found to have a lower frequency of axillary metastasis than IDC. IPC was noted to have a lower frequency of T3-stage and lymphovascular invasion than IDC. A higher expression of PR and lower frequency of HER2/neu expression was noted in IPC than IDC. Conclusion IPC is a rare malignant papillary breast tumor with a wide differential diagnosis and therefore poses a significant diagnostic challenge. We found that IPC had a favorable pathological profile than IDC, in terms of T-stage, Ki67 index, axillary metastasis, PR and HER2/neu expression.

Double-Expressor Phenotype (BCL-2/c-MYC Co-expression) of Diffuse Large B-Cell Lymphoma and Its Clinicopathological Correlation.

Introduction Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease, the spectrum of which is increasing with time. The 2016 World Health Organization (WHO) update on hematopoietic tumors recognized a prognostic subgroup of DLBCL called double-expressor DLBCL. Double-expressor DLBCL is defined by the co-expression of c-MYC and BCL-2 by using immunohistochemical (IHC) studies. To our knowledge, very few studies have looked into the pathological features of this newly defined prognostic category of DLBCL; therefore, in this study we evaluated the frequency of the double-expressor phenotype of DLBCL and its association with other clinicopathological parameters. Methods We conducted a retrospective observational study in the Department of Histopathology, Liaquat National Hospital and Medical College, from November 2017 till December 2020. Pathological and clinical records were retrieved from departmental archives. All cases diagnosed as DLBCL were included in the study. More than 40% c-MYC expression in the presence of more than 50% BCL-2 expression was defined as double-expressor DLBCL. Results The mean age of the patients was 52.1±16.9 years. The mean Ki67 index was 73.0±17.0%. A total of 48.6% cases were of germinal center B-cell-like (GCB) subtype, and 59.6% cases were nodal. Double-expressor phenotype was noted in 35.8% of DLBCL cases. A significant association of double-expressor phenotype was noted with age, gender, Ki67 index and subtype of DLBCL. Double-expressor DLBCL had a higher mean age than non-double-expressor DLBCL. Similarly, double-expressor DLBCL had a higher Ki67 index. Moreover, double-expressor phenotype was associated with non-GCB subtype DLBCL. Conclusion We found a high proportion of double-expressor phenotype DLBCL in our population. Moreover, double-expressor phenotype DLBCL was associated with female gender, higher age, higher Ki67 and non-GCB subtype. The association of double-expressor DLBCL with a high Ki67 index and non-GCB subtype confers a poor prognostic significance of this variant of DLBCL, requiring more aggressive therapy.

CD30-Positive Anaplastic Variant of Diffuse Large B-cell Lymphoma: Frequency and Association With Clinicopathological Parameters.

Introduction Diffuse large B-cell lymphoma (DLBCL) is an aggressive B-cell lymphoma and is the most common type of non-Hodgkin's lymphoma (NHL) worldwide. The World Health Organization (WHO) classification of hematopoietic tumors has recognized three morphological variants of DLBCL: centroblastic, immunoblastic, and anaplastic. Some studies have shown that the anaplastic variant of DLBCL is associated with aggressive clinicopathological features. Anaplastic DLBCL is rare, and the clinicopathological characteristics of this subtype of DLBCL are not widely studied in our population. Therefore, in this study, we evaluated the frequency of the anaplastic variant of DLBCL and its association with other clinicopathological parameters. Methods A retrospective study was conducted in the Department of Histopathology at the Liaquat National Hospital and Medical College over a period of six years, from January 2015 to December 2020. All cases diagnosed as DLBCL based on morphology and immunohistochemical (IHC) profile were included in the study. The diagnosis of anaplastic DLBCL was rendered based on morphology (large bizarre pleomorphic cells in a cohesive or sheet-like growth pattern), combined with CD30 IHC expression. Results The mean age of the patients was 52.90 ±16.42 years, and the mean Ki67 index was 73.18 ±16.52%. Of the 220 cases of DLBCL, 47.3% cases were germinal center B-cell (GCB) subtype, and 59.1% cases were nodal. BCL-2, BCL-6, MUM1, c-MYC, and CD10 positivity were noted in 60%, 45.5%, 40.9%, 44.1, and 38.6% cases, respectively. Only 14 cases (6.4%) were recognized as anaplastic variants of DLBCL according to the previously defined criterion. The only significant association of anaplastic-variant DLBCL was noted with a lack of BCL-2 expression. No significant association of anaplastic-variant DLBCL was noted with age, gender, Ki67 index, DLBCL subtype, or any other IHC marker expression. Conclusion We found a low frequency of the anaplastic variant of DLBCL in our study. No significant association of this DLBCL variant was noted with any of the clinicopathological parameters, except for the lack of BCL-2 expression. Alternatively, from a pathological perspective, it is important to recognize this variant of DLBCL as it often mimics other CD30-positive lymphoma and undifferentiated carcinoma.

Diagnostic Accuracy of Intraoperative Touch Imprint Cytology for the Diagnosis of Axillary Sentinel Lymph Node Metastasis of Breast Cancer: Comparison With Intraoperative Frozen Section Evaluation.

Introduction The intraoperative frozen section is a recommended method to detect breast cancer metastasis to axillary sentinel lymph nodes (SLNs); however, frozen section is not widely available and requires an experienced staff. Alternatively, touch imprint cytology (TIC) is a simple and cost-effective technique to detect metastasis. Therefore, in this study, we assessed the diagnostic accuracy of TIC for detecting SLN metastasis and compared it with intraoperative frozen section evaluation. Methodology A retrospective study was conducted in the Department of Histopathology, Liaquat National Hospital and Medical College, for a duration of two years. A total of 114 patients undergoing surgery for primary breast cancer were included in the study. All patients had clinically and radiologically negative axillary lymph nodes. SLN sampling was done using radioactive dye and sent for intraoperative consultation. The SLNs were sliced at 4-mm intervals and two TIC slides and three step-levels for frozen section were prepared, and the results were compared with final (paraffin) section histology. Results The sensitivity, specificity, and diagnostic accuracy of TIC was 83.7%, 98.5%, and 92.1%, respectively. Alternatively, the sensitivity, specificity, and diagnostic accuracy of frozen section was 93.9%, 100%, and 97.4%, respectively. The sensitivity of TIC and frozen section for detecting micrometastasis was 14.3% and 57.1%, respectively, with a diagnostic accuracy of 90.3% and 95.8%, respectively. Alternatively, with respect to macrometastasis, the sensitivity and specificity of TIC were 95.2% and 98.5%, respectively, while the sensitivity and specificity of frozen section were 100%. Conclusion TIC is a quick and effective technique for detecting breast cancer metastasis in axillary SLNs. Although frozen section had an overall higher sensitivity than TIC, the sensitivity of TIC for detecting macrometastasis was comparable to the frozen section. Therefore, we conclude that TIC is a good alternative to the frozen section in facilities where the frozen section is not available.

Ki67 Proliferation Index in Germinal and Non-Germinal Subtypes of Diffuse Large B-Cell Lymphoma.

Introduction Diffuse large B-cell lymphoma (DLBCL) is an aggressive B-cell lymphoma. The 2016 World Health Organization (WHO) update on hematopoietic tumors suggested that all DLBCL cases should be subtyped into germinal and non-germinal center phenotypes. Ki67 immunohistochemistry is a maker of cell proliferation and thus is used as a prognostic and predictive marker in various tumors of human body. Only a few studies evaluated the proliferative index of DLBCL subtypes in our population. Therefore, in this study, we evaluated the frequency of subtypes of DLBCL in our population and K67 index in each subtype. Methods A retrospective observational study was conducted in the Department of Histopathology, Liaquat National Hospital and Medical College, from January 2018 till December 2020, over a period of three years. A total of 101 cases with a histopathological diagnosis consistent DLBCL were included in the study. Immunohistochemical (IHC) stains CD10, B-cell lymphoma 6 (Bcl-6), and multiple myeloma oncogene 1 (MUM1) were applied for the further sub-categorization of DLBCL into germinal center B-cell-like (GCB) and non-GCB subtypes according to the Hans algorithm. The Ki67 index was interpreted in hot spots of the tumor and reported as an average percentage. Results Out of 101 DLBCL cases, 47.5% of DLBCL were GCB, while 52.5% were non-GCB subtypes. Bcl-2, Bcl-6, MUM1, c-Myc, CD10, and CD30 expression were noted in 62.4%, 45.5%, 42.6%, 44.6%, 39.6%, and 7.9% cases, respectively. The mean Ki67 index was 72.94±16.69%. The mean Ki67 index in non-GCB-type DLBCL was 77.67±14.80%, which was significantly higher than the mean Ki67 index in GCB-type DLBCL (67.70±17.22%) with a significant p-value (p=0.002). Cervical lymph node was the most common site of DLBCL, while the stomach was the most common extra-nodal site. A significant association of Ki67 index was noted with subtypes of DLBCL. A higher proportion of non-GCB-type DLBCL exhibited greater than 80% Ki67 index than GCB subtype DLBCL. Moreover, a significant association Ki67 index was noted with c-Myc positivity. A higher proportion of c-Myc-positive DLBCL had greater than 80% Ki67 index. Conclusion We found that non-GCB-type DLBCL had a higher Ki67 index than GCB subtype DLBCL, portending a poor prognostic significance of non-GCB subtype of DLBCL. Moreover, c-Myc expression was associated with a higher Ki67 index.

Frequency of Blood Transfusion in Percutaneous Nephrolithotomy.

Introduction Percutaneous nephrolithotomy (PNL) has replaced open surgery for the treatment of kidney stones due to its less invasive nature. Bleeding still occurs due to renal vascular injuries, dependent upon the access route of the procedure. Several other factors are also related to the increased risk of bleeding. This study aims to find the association between blood transfusion and other factors such as age, gender, body mass index (BMI), size of the stone, operative time, preoperative hemoglobin (Hb) level, stone surface area, hypertension, and diabetes mellitus. Materials and methods This was a descriptive cross-sectional study conducted over a period of six months between November 2019 and April 2020 at a tertiary care hospital in Karachi, Pakistan. The sample size of 131 patients was calculated using open-source epidemiological software (Open-Epi). Inclusion criteria included patients from both genders and ages between 26 and 70 years. Patients ≤25 years, having a liver disease or bleeding disorders, or refusing to participate in the study, were excluded. Laboratory data included preoperative routine complete blood count, serum creatinine (normal 0.5-1.5 mg/dL), platelet count, bleeding and coagulation profile, and urine culture. All patients also underwent renal ultrasound scans. Treatment was postponed until a negative urine culture was obtained from patients with a positive urine culture.  Results The mean age of the patients was 42.4 ± 15.65 years. One third (29.8%) of the patients were females. The stone size was 850 ± 121.43 mm², the mean operative time of the procedure was 125.76 ± 53.4 minutes, and the mean number of cell packs transfused was 1.10 ± 0.31 units. Blood transfusion was done in 24 (18.3%) of the patients. Gender, diabetes mellitus, stone size, preoperative Hb level, and operative time were significantly related to blood transfusion.  Conclusions Increased bleeding risk while performing PNL has been associated with many factors such as operating time, the gender of the patients, and stone size. Therefore, these factors should be controlled for the procedure to decrease the risk of bleeding and the need for blood transfusion. Furthermore, the kidney vasculature should not be compromised while performing the procedure.

B-Cell Acute Lymphoblastic Leukemia Presenting as Leukemia Cutis: A Case Report.

Leukemia cutis (LC) is a manifestation of leukemia with infiltration of the dermis, epidermis, or subcutis by malignant leukocytes resulting in papules, plaques, nodules, or ulcers. It is usually associated with acute and chronic myeloid leukemia as well as T-cell acute lymphoblastic leukemia (T-ALL) but is very rare in patients with B-cell acute lymphoblastic leukemia (B-ALL). We report a case of a 58-year-old Hispanic male who presented with a non-healing leg ulcer of three months along with patches on the face, left arm, and bilateral legs with white blood cell (WBC) count of 50800/mm3 with 83% blasts, and flow cytometry findings of B-ALL. Punch biopsies from affected skin showed numerous dermal nodules composed of large atypical cells with open chromatin and prominent nucleoli. Immunohistochemical stains were consistent with B-ALL involving the skin and a diagnosis of LC was rendered. A high index of suspicion in relevant cases and prompt diagnosis is imperative to prevent any delays in appropriate therapy. Diagnosis in our case was aided by concurrent identification of B-ALL in the patient's peripheral blood. Since this information may not always be available, it is important to keep B-ALL in the differential any time there is a neoplastic infiltration of leukocytes in the dermis.

Solitary Fibrous Tumor of Pancreas With Unusual Features: A Case Report.

Solitary fibrous tumor (SFT) is an uncommon fibroblastic neoplasm that is most commonly associated with the pleura but has also been reported in almost all anatomic sites. Although the majority of SFTs are benign, few cases follow a malignant clinical course and may recur and/or metastasize after several years of their original occurrence. Only 16 cases of pancreatic SFTs are reported so far, and only one has metastasized to lung and subcutis. Pancreatic SFT resembles more common neuroendocrine tumor and gastrointestinal stromal tumor (GIST) radiographically and is at times almost indistinguishable from GIST histologically. Diagnosis of SFTs particularly, if attempted on biopsied specimens, can be very challenging due to its rare occurrence and nondescript morphology. It is imperative to understand the pathological spectrum of this entity to avoid misdiagnosis. We report a case of pancreatic SFT in a 43-year-old male with some unusual morphologic and immunohistochemical features including pseudoangiomatous growth pattern, a hypercellular area demonstrating nuclear pleomorphism, and only focal positivity for cluster of differentiation (CD)34. These atypical features can pose even more diagnostic challenge by causing additional confusion with other malignancies like dedifferentiated liposarcoma and vascular tumors. The potential diagnostic pitfalls are discussed.

Turquoise Discoloration of Organs on Autopsy Secondary to Treatment of Septic Shock With Methylene Blue.

Septic shock can result from the dissemination of infections and can lead to hypoperfusion secondary to vasodilation. Methylene blue can help stabilize blood pressure refractory to other measures in shock. We report a case of a 58-year-old male who died of septic shock due to Pseudomonas aeroginosa bacteremia secondary to acute folliculitis and epididymo-orchitis. He was given methylene blue for reversal of septic shock but he did not respond and expired. Autopsy findings were significant for bluish-green discoloration of organs, especially the heart, lungs, and brain during prosection secondary to methylene blue treatment. It is important to recognize artifacts of treatment and to discern them from changes due to putrefaction or the classic green pigmentation associated with Pseudomonas aeruginosa infection, such as chloronychia. The case report illustrates that circulating methylene blue and its metabolites can accumulate in the organs in a dose-related fashion, imparting an interesting turquoise to dark blue-green pigment during the autopsy. Additional studies are warranted to enable pathologists to differentiate among the pigmentation associated with Pseudomonas aeruginosa bacteremia, putrefaction, and methylene blue treatment.

Monomorphic Epitheliotropic Intestinal T-Cell Lymphoma With Extraintestinal Areas of Peripheral T-Cell Lymphoma Involvement.

Monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL) is a primary intestinal T-cell lymphoma, previously known as enteropathy-associated T-cell lymphoma (EATL) type II. Its clinical, morphologic, and immunophenotypic features distinguishing it from the more common EATL (previously EATL type I) made it a separate entity. Unlike EATL, MEITL typically is noted in Asian, Hispanic, and indigenous populations; it is rarer in native European and Caucasian populations. Due to its poor prognosis, it needs to be distinguished from inflammatory diseases and less aggressive T-cell lymphomas. We present an unusual case of MEITL in a Caucasian patient who developed nonspecific GI symptoms and was diagnosed with MEITL of the jejunum, mesenteric lymph nodes, and multiple extraintestinal sites based on histology, immunophenotype, molecular testing, and imaging. Despite aggressive treatment, he expired about seven months after the definitive diagnosis.

T-cell Therapy-Mediated Myocarditis Secondary to Cytokine Release Syndrome.

Chimeric antigen receptor (CAR) T-cell therapy is expanding to a wider patient population; however, cytokine release syndrome (CRS) is the most important adverse event of these therapies. Patients suffering from high-grade CRS also develop signs of cardiac dysfunction and frequently manifest vascular leakage with peripheral and pulmonary edema. We present an unusual case of a 68-year-old female with stage III endometrial carcinosarcoma, who was admitted for T-cell therapy. The patient developed symptoms of CRS within 12 hours of T-cell therapy and expired shortly thereafter. Autopsy of the patient revealed interstitial edema and lymphocytic infiltrates in right and left ventricles along with foci of myocyte necrosis and perivascular fibrosis, more prominent in the right ventricle, consistent with immune therapy-mediated myocarditis. It is important to recognize that CRS progresses rapidly and can have potentially dangerous consequences, so it is imperative to anticipate and treat it early. Cases should be individualized and treated accordingly.

Decidualized Stroma in Pelvic Lymph Nodes in a Pregnant Patient With Cervical Squamous Cell Carcinoma: A Case Report.

Decidualized endometrial stroma is an uncommon finding in lymph nodes but is typically found in the setting of endometriosis where endometrial glands give a hint toward the diagnosis. On the other hand, endometrial stroma with no identifiable endometrial glands can be challenging to differentiate from metastatic squamous cell carcinoma. We report a case of a 22-year-old female who presented to our medical center as a known case of cervical squamous cell carcinoma. The patient desired future fertility and became pregnant. She was treated during her second trimester and underwent a radical cesarean hysterectomy at 37 weeks' gestation with bilateral pelvic lymph node dissection. Resection showed residual moderately differentiated squamous cell carcinoma of the cervix with lymphovascular invasion. Two pelvic lymph nodes were found to have decidualized stroma. Immunohistochemistry was done to rule out metastasis and no metastatic carcinoma was identified in any of the lymph nodes. It is necessary to be aware of the possibility of decidualized stromal changes in pelvic lymph nodes to avoid misdiagnosis.