Hyalinizing clear cell carcinoma of the salivary gland is a rare neoplasm, accounting for only less than 1% of malignancies arising from the salivary gland. It is molecularly defined by the expression of the EWSR-ATF1 fusion oncogene. To date, there has been no previous studies published yet in the Philippines regarding the existence of this tumor. In this paper, we present a case of a 70-year-old elderly female who had a 10-year history of a gradually enlarging left lateral neck mass. Histopathologic examination showed a tumor arranged of cords, nests, and trabeculae of monomorphic round cells with abundant clear to lightly eosinophilic cytoplasm surrounded by thick hyalinized collagen bundles. Immunohistochemistry and molecular studies were done which revealed a positive p63 staining, negative SMA and S100, and an EWSR1 rearrangement in Fluorescence in situ hybridization (FISH), thus, confirming the diagnosis.

BACKGROUND

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma (NHL). Classification of DLBCL is often based on the cell of origin (COO), distinguishing between germinal center B-cell (GCB) and non-GCB subtypes. Although not yet recognized as a distinct entity by the World Health Organization (WHO), double expressor lymphoma (DEL), characterized by the co-expression of c-MYC and BCL2, carries an unfavorable prognosis for a subgroup of DLBCL patients. Another entity is the so-called high-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements (double-hit/triple-hit lymphomas) diagnosed through fluorescent in-situ hybridization (FISH) analysis.

This study aimed to determine the clinicopathologic profile and survival outcomes of Filipino DLBCL patients at the Philippine General Hospital (2016-2021), comparing double-hit versus non-double-hit and doubleexpressor versus non-double-expressor lymphomas, and assessing concordance between FISH-measured double-hit and IHC-measured double-expressor statuses.

This is a single-arm, retrospective cohort study involving all surgical pathology cases signed out, with the aid of immunohistochemistry (IHC) studies, as NHL DLBCL, GCB, or non-GCB subtype, from 2016 to 2021. A second panel of IHC studies and FISH analysis using tissue microarray was subsequently done. Most cases exhibited a nonGCB subtype and were classified as DEL on second IHC panel. Five out of eleven DEL cases were reclassified as double hit lymphoma (DHL).

Clinically, most patients with these lymphomas present at age 60 years and below, exhibit B symptoms, with elevated serum lactate dehydrogenase (LDH) levels, at least stage III-IV disease at diagnosis, and possess a high International Prognostic Index (IPI) score, collectively indicating a poor prognosis.

Survival outcomes for patients with DLBCL ranges from three to 37 months. All cases of mortality were associated with DEL, contrasting with DHL cases which had variable outcomes. Due to limited sampling, statistical significance of the results cannot be determined. A comprehensive evaluation is essential to the diagnosis of DLBCL and DHL to include a complete immunohistochemistry panel and molecular testing, notably with FISH studies.

Gliomatosis peritonei (GP) is a condition characterized by the dissemination of mature glial tissues throughout the peritoneal cavity. It is usually associated with immature ovarian teratoma but presents with mature cystic teratoma (MCT) in 1% of cases. GP, associated with MCT, is a benign disorder. The majority of cases remain asymptomatic and rarely recur. Here, we present a case of a 22-year-old woman with a history of abdominal enlargement and severe abdominal pain who underwent exploratory laparotomy, peritoneal fluid cytology, bilateral salpingo-oophorectomy, appendectomy, omental biopsy, and Jackson-Pratt drain insertion with histopathologic result of GP with MCT. A month later, the patient had a recurrence of abdominal enlargement, necessitating a second surgery. Immunohistochemistry for histopathologic evaluation and diagnostic imaging are crucial in confirming the diagnosis and guiding the treatment strategy. A multidisciplinary team approach in monitoring and comprehensive support is significant in optimizing outcomes for patients with aggressive GPs associated with MCT. Further research and clinical experience are essential to establish a standardized guideline to improve the management and clinical outcome of this condition.

Mucinous tubular and spindle cell carcinoma (MTSCC) is a rare neoplasm of the kidney. Recognition of this rare entity is important with regards to a patient’s prognosis and therapeutic management.
Kidney Neoplasms ; Immunohistochemistry ; Pathology, Surgical

Background: Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma (NHL). Classification of DLBCL is often based on the cell of origin (COO), distinguishing between germinal center B-cell (GCB) and non-GCB subtypes. Although not yet recognized as a distinct entity by the World Health Organization (WHO), double expressor lymphoma (DEL), characterized by the co-expression of c-MYC and BCL2, carries an unfavorable prognosis for a subgroup of DLBCL patients. Another entity is the so-called high-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements (double-hit/triple-hit lymphomas) diagnosed through fluorescent in-situ hybridization (FISH) analysis. Objective: This study aimed to determine the clinicopathologic profile and survival outcomes of Filipino DLBCL patients at the Philippine General Hospital (2016-2021), comparing double-hit versus non-double-hit and doubleexpressor versus non-double-expressor lymphomas, and assessing concordance between FISH-measured double-hit and IHC-measured double-expressor statuses. Methods: This is a single-arm, retrospective cohort study involving all surgical pathology cases signed out, with the aid of immunohistochemistry (IHC) studies, as NHL DLBCL, GCB, or non-GCB subtype, from 2016 to 2021. A second panel of IHC studies and FISH analysis using tissue microarray was subsequently done. Most cases exhibited a nonGCB subtype and were classified as DEL on second IHC panel. Five out of eleven DEL cases were reclassified as double hit lymphoma (DHL). Results: Clinically, most patients with these lymphomas present at age 60 years and below, exhibit B symptoms, with elevated serum lactate dehydrogenase (LDH) levels, at least stage III-IV disease at diagnosis, and possess a high International Prognostic Index (IPI) score, collectively indicating a poor prognosis. Conclusion Survival outcomes for patients with DLBCL ranges from three to 37 months. All cases of mortality were associated with DEL, contrasting with DHL cases which had variable outcomes. Due to limited sampling, statistical significance of the results cannot be determined. A comprehensive evaluation is essential to the diagnosis of DLBCL and DHL to include a complete immunohistochemistry panel and molecular testing, notably with FISH studies.
lymphoma ; lymphoma, large B-cell, diffuse ; cytogenetics ; immunohistochemistry

Humans ; Female ; Receptors, Estrogen/metabolism* ; Breast Neoplasms/metabolism* ; Receptors, Progesterone/metabolism* ; Immunohistochemistry ; Estrogen Receptor alpha

Nephroblastoma is an uncommon renal malignancy primarily observed in the pediatric population, with its occurrence in adults being exceedingly infrequent. We describe an extremely rare case of a malignant embryonal tumor presenting in an adult patient with right renal mass. Final histopathologic diagnosis was nephroblastoma with favorable histology. Use of immunohistochemistry studies is generally unnecessary but its rarity in the adult population raises uncertainty in diagnosing this malignancy by histomorphology alone.

A 31-year-old Indian female with a history of near-total thyroidectomy 2.5-years prior presented with recurrent neck swelling. Magnetic resonance imaging (MRI) of the neck revealed an infiltrating mass involving the thyroid bed. Biopsy from the mass and review of slides from the previous thyroidectomy revealed a spindle cell tumour with interspersed areas of fibrosis and infiltrative edges entrapping thyroid follicles. Beta-catenin immunopositivity and CTNNB1 mutation confirmed the diagnosis of fibromatosis. The case is being reported for its rarity and the discussion of its differential diagnoses.
thyroid ; fibromatosis ; immunohistochemistry ; molecular ; Thyroid Nodule

Humans ; Aged ; Lymphoma, Large B-Cell, Diffuse/pathology* ; Immunohistochemistry

Solid pseudopapillary neoplasm (SPN) is a rare pancreatic neoplasm. This case reports a 63-year-old female previously diagnosed with bilateral adrenocortical carcinoma post resection who presents with persistent epigastric pain. Suspicions for recurrence prompted diagnostics revealing retropancreatic and left suprarenal foci, both suspicious for malignancy. Resection of both tumors yielded a moderately to poorly differentiated retropancreatic carcinoma with differentials not limited to recurrence and pancreatic neuroendocrine tumor with a left suprarenal lymph node. Immunohistochemistry was then done and was consistent with SPN having a strong expression for b-catenin, vimentin, pancytokeratin. It was non-specific to melan-A and negative for chromogranin A, synaptophysin, inhibin-a and CD10. At 6 months’ follow up, patient is clinically well and abdominal CT scan showed no recurrence. SPNs can masquerade as other neoplasms having similar clinical, radiologic and histopathologic features. Immunohistochemistry thus plays a crucial role for accurate diagnosis and management. Surgical resection still remains the treatment of choice and can provide a 95% overall survival rate, while limited evidence supports the use of adjuvant chemotherapy or radiation.
Immunohistochemistry