Intrinsic molecular subtypes of breast cancers categorized as HER2-positive using an alternative chromosome 17 probe assay

Abstract The 2013 update of the American Society of Clinical Oncology-College of American Pathologists (ASCO-CAP) human epidermal growth factor receptor 2 (HER2) testing guidelines recommend using an alternative chromosome 17 probe assay to resolve HER2 results determined to be equivocal by immunohistochemistry (IHC) or fluorescence in-situ hybridization (FISH). However, it is unclear if cases considered HER2-positive (HER2+) by the alternative probe method are similar to those classified as HER2+ by traditional IHC and FISH criteria and benefit the same from HER2-targeted therapies. We studied the clinical and pathologic features of all 31 breast cancers classified as HER2+ by the alternative probe method at our institution since 2013 and determined their PAM50 intrinsic molecular subtypes. For comparison, we analyzed 19 consecutive cases that were classified as HER2+ by traditional FISH criteria during the same time period. Thirty (97%) cancers in the alternative probe cohort were estrogen receptor (ER)-positive (ER+), while only 9/19 (47%) of traditional HER2 controls were ER+ (p = 0.0002). Sufficient tissue for intrinsic subtype analysis was available for 20/31 cancers in the alternative probe cohort and 9/19 in the traditional HER2+ group. None (0%) of the 20 alternative probe-positive cases were of the HER2-enriched intrinsic subtype, while 8/9 (89%) of those HER2+ by traditional FISH criteria were HER2-enriched (p = 0.0001). These findings suggest that breast cancers classified as HER2+ only by the alternative probe method are biologically distinct from those classified as HER2+ by traditional criteria, and raises questions as to whether or not they derive the same benefit from HER2-targeted therapies

Nanoscale imaging of clinical specimens using pathology-optimized expansion microscopy

Expansion microscopy (ExM), a method for improving the resolution of light microscopy by physically expanding the specimen, has not been applied to clinical tissue samples. Here we report a clinically optimized form of ExM that supports nanoscale imaging of human tissue specimens that have been fixed with formalin, embedded in paraffin, stained with hematoxylin and eosin (H&E), and/or fresh frozen. The method, which we call expansion pathology (ExPath), converts clinical samples into an ExM-compatible state, then applies an ExM protocol with protein anchoring and mechanical homogenization steps optimized for clinical samples. ExPath enables ~70 nm resolution imaging of diverse biomolecules in intact tissues using conventional diffraction-limited microscopes, and standard antibody and fluorescent DNA in situ hybridization reagents. We use ExPath for optical diagnosis of kidney minimal-change disease, which previously required electron microscopy (EM), and demonstrate high-fidelity computational discrimination between early breast neoplastic lesions that to date have challenged human judgment. ExPath may enable the routine use of nanoscale imaging in pathology and clinical research

Adult Patient with Synchronous Gastrointestinal Stromal Tumor and Xp11 Translocation-Associated Renal Cell Carcinoma: A Unique Case Presentation with Discussion and Review of Literature

Gastrointestinal stromal tumor (GIST) is the most common primary mesenchymal tumor of the gastrointestinal tract. This entity comprises a wide spectrum of tumors that vary from benign to overtly malignant, with the majority of these tumors harboring oncogenic mutations of the KIT receptor tyrosine kinase that can aid in diagnosis as well as in targeted therapy. Although the majority of GISTs are sporadic, there are forms that are associated with a variety of syndromes including Carney-Stratakis syndrome and neurofibromatosis type 1, as well as a subset of familial GIST syndromes that are caused by germline mutations in KIT or PDGFRA. Here, we describe an unusual case of a patient who was found to have a large abdominal GIST with an incidentally found Xp11 translocation-associated renal carcinoma. The karyotype of the renal carcinoma revealed an unbalanced rearrangement involving an (X;22) translocation at Xp11.2 and 22p11.2, which has not been reported in the literature. Although GISTs have shown an association with other primary malignant neoplasms, including simultaneous presence with unilateral clear cell renal cell carcinoma and bilateral papillary renal cell carcinomas, we describe the first reported case of synchronous GIST and Xp11 translocation-associated renal cell carcinoma

Osteochondroma of the Hyoid Bone: A Previously Unrecognized Location and Review of the Literature

Osteochondroma is a benign cartilaginous neoplasm and the most common benign tumor of bone. Osteochondromas occur primarily in the axial skeleton with a predilection for the distal femur, and relatively few cases occur in the head and neck region. The majority of cases of osteochondromas in the head and neck region affect the mandibular condyle, with fewer cases reported in the skull base and the neck. To our knowledge, there is no reported case of osteochondroma of the hyoid bone documented in the English literature. We thus report the first case of a hyoid bone osteochondroma, presenting as an asymptomatic mass in a young woman

Cholangitis Lenta: A Clinicopathologic Study of 28 Cases.

Cholangitis lenta, also known as ductular cholestasis, cholangiolar cholestasis, or subacute nonsuppurative cholangitis, is an uncommon type of cholangitis characterized by ductular reaction with inspissated bile in dilated ductules. The literature on this unique entity has been limited to only a few studies based on a very limited number of cases, which importantly suggest an association with sepsis and/or intra-abdominal infection. The clinical, laboratory, and histologic features of 28 cases of cholangitis lenta are herein investigated. Twenty-five (89.3%) patients were liver transplant recipients. Most notably, the majority of patients showed clinical signs and symptoms of sepsis, and positive microbiology cultures were demonstrated in 24 (85.7%) patients. Significantly, 15 (53.6%) patients died during their hospitalization, ranging from 2 days to 5 months after the initial liver biopsy that showed histologic features of cholangitis lenta. Among the 13 discharged patients, including 2 who received retransplantation, 4 (14.3%) subsequently died of pneumonia, graft dysfunction, or fungal infection within 7 months to 9.3 years. Only 9 (32.1%) patients were alive at the last follow-up, with the follow-up time ranging from 3.8 to 10.4 years. Our data show that the finding of cholangitis lenta on liver biopsy is thus frequently associated with sepsis and with a high mortality rate. Therefore, accurate diagnosis of this condition on liver biopsy is imperative as it is an indication that the patient may have a potentially life threatening condition that requires immediate medical attention and management

Intrinsic molecular subtypes of breast cancers categorized as HER2-positive using an alternative chromosome 17 probe assay

Abstract The 2013 update of the American Society of Clinical Oncology-College of American Pathologists (ASCO-CAP) human epidermal growth factor receptor 2 (HER2) testing guidelines recommend using an alternative chromosome 17 probe assay to resolve HER2 results determined to be equivocal by immunohistochemistry (IHC) or fluorescence in-situ hybridization (FISH). However, it is unclear if cases considered HER2-positive (HER2+) by the alternative probe method are similar to those classified as HER2+ by traditional IHC and FISH criteria and benefit the same from HER2-targeted therapies. We studied the clinical and pathologic features of all 31 breast cancers classified as HER2+ by the alternative probe method at our institution since 2013 and determined their PAM50 intrinsic molecular subtypes. For comparison, we analyzed 19 consecutive cases that were classified as HER2+ by traditional FISH criteria during the same time period. Thirty (97%) cancers in the alternative probe cohort were estrogen receptor (ER)-positive (ER+), while only 9/19 (47%) of traditional HER2 controls were ER+ (p = 0.0002). Sufficient tissue for intrinsic subtype analysis was available for 20/31 cancers in the alternative probe cohort and 9/19 in the traditional HER2+ group. None (0%) of the 20 alternative probe-positive cases were of the HER2-enriched intrinsic subtype, while 8/9 (89%) of those HER2+ by traditional FISH criteria were HER2-enriched (p = 0.0001). These findings suggest that breast cancers classified as HER2+ only by the alternative probe method are biologically distinct from those classified as HER2+ by traditional criteria, and raises questions as to whether or not they derive the same benefit from HER2-targeted therapies