Validating the diagnostic accuracy of an MRI-based scoring system for differentiating benign uterine leiomyomas from leiomyosarcomas.

OBJECTIVE: Uterine leiomyomas are the most common benign uterine tumors. They are difficult to distinguish from their malignant counterparts-smooth muscle tumors of unknown malignant potential (STUMP) and leiomyosarcoma. The purpose of this study is to propose and validate the diagnostic accuracy of the MRI-based Oman-Canada Scoring System of Myometrial Masses (OCSSMM) to differentiate uterine leiomyomas from STUMP/leiomyosarcomas. METHODS: This is a retrospective study performed at two tertiary care centers. All patients with a pathology-proven uterine mass who underwent pre-operative pelvic MRI between January 2010 and January 2020 were included. Using a 1.5T MRI machine, sequences included were axial/coronal/sagittal T2 and T1 weighted imaging, axial diffusion weighted and apparent diffusion coefficient map, and axial or sagittal dynamic contrast-enhanced sequences. A scoring system was designed based on previously published worrisome MRI features for uterine leiomyosarcoma. Each feature was allocated a score from 0 to 2 according to the strength of association with malignancy. Subsequently, the MR images were blindly and independently reviewed by a fellowship-trained radiologist and a clinical fellow/senior resident. Each uterine mass was scored according to their imaging features. The scores were divided into five categories according to the sum of scores. Category III and above was considered positive for leiomyosarcoma/STUMP. Sensitivity, specificity, and positive and negative predictive values were calculated. RESULTS: A total of 244 women were included (age range 20-74 years, mean 40). Of these, 218 patients had benign leiomyoma, 13 had STUMP, and 13 had leiomyosarcoma. The sensitivity and specificity of the scoring system were 92.3% and 64.7%, respectively. The negative predictive value was 98.6%. No leiomyosarcoma was missed using this scoring system. The presence of non-cystic T2 hyperintensity or diffusion restriction in a uterine mass were the most sensitive signs of a leiomyosarcoma/STUMP. CONCLUSION: The proposed multi-parametric MRI scoring system may be useful in differentiating benign uterine leiomyomas from leiomyosarcomas/STUMP.

The Alveolar Variant of Lobular Carcinoma and Its Mimickers: A Case Series.

Invasive lobular carcinoma (ILC) is the most common special type of invasive breast cancer (IBC), accounting for 5-15% of IBCs. The distinct histomorphology of ILC reflects a special tumor biology, the hallmark of which is the lack of E-cadherin expression. However, the occasional presence of E-cadherin expression and the presence of IBC of no special type (IBC, NST)-like morphologies in ILC and vice versa make the diagnosis challenging.  We present two cases of the alveolar variant of ILC, a diagnostically challenging entity. The first case is an 81-year-old female with two discrete right breast masses at 1 o'clock and 9 o'clock positions.  The second case is a 61-year-old female with two discrete left breast masses located at 11 o'clock and 12 o'clock positions. Core needle biopsies and subsequent mastectomy were performed in both cases. On histology, three tumor foci were identified in the first case. The 1 o'clock focus showed IBC, NST, grade 3/3, ductal carcinoma in situ (DCIS) and lobular carcinoma in situ (LCIS). The 9 o'clock focus revealed ILC, classic and alveolar variants, grade 2/3, while a nearby third incidental focus was ILC, alveolar variant, both supported by lack of E-cadherin and ß-catenin immunostaining.  The second case showed ILC, alveolar variant, grade 1 with LCIS component in the 11 o'clock lesion on both biopsy and mastectomy specimens. The lesion at the 12 o'clock position was diagnosed as IBC, NST, grade 2 with high-grade DCIS and LCIS components.  It is challenging to distinguish the alveolar variant of ILC from IBC, NST, and in situ lesions because of the overlapping morphology and occasional E-cadherin expression. Altered adherence of lobular cells may also be due to loss of α-, ß-, and γ-catenins, and cytoplasmic re-localization of p120-catenin. Therefore, in ILC, the lack of ß-catenin can be used as an adjunct along with E-cadherin. Myoepithelial markers such as p63 and smooth muscle myosin heavy chain (SMMHC) can be used to distinguish the alveolar variant of ILC from LCIS.

Intraoperative pathology consultation: error, cause and impact.

BACKGROUND: Correlation of intraoperative frozen section diagnosis with final diagnosis can be an important component of an institution's quality assurance process. METHODS: We performed a quality assurance review of 1207 frozen section diagnoses from 812 surgical cases performed in the Hamilton Regional Laboratory Medicine Programme during a 6-month period in 2007. We reviewed the frozen section and permanent slides from all potentially discordant cases using a multiheaded microscope to arrive at a consensus pertaining to the type and reason for error. We reviewed the clinical record to determine whether there had been a potential adverse impact on immediate clinical management. RESULTS: Frozen sections were most commonly requested for head and neck, nervous system and female genital tract specimens. Twenty-eight frozen sections (3%) were deferred. We identified 24 discordant diagnoses involving 3% of cases and 2% of specimens. The organ systems showing the greatest frequency of discordance relative to the total number from that system were the nervous system, head and neck, and the lungs. Of the errors identified, most occurred owing to diagnostic misinterpretation, followed by problems related to tissue sampling. There was a potential adverse impact on immediate clinical management in 14 cases. CONCLUSION: Our results add to the Canadian data on the correlation between frozen sections and permanent sections; we note comparability to the concordance rates reported in the literature.

CONTEXTE: La corrélation entre le diagnostic fondé sur une analyse peropératoire des coupes congelées et le diagnostic final pourrait être un élément important du processus d'assurance qualité dans les établissements de santé. MÉTHODES: À des fins d'examen de l'assurance qualité, le Programme régional de médecine de laboratoire d'Hamilton a procédé à une revue de 1207 diagnostics fondés sur l'analyse de coupes congelées prélevées lors de 812 interventions chirurgicales au cours d'une période de 6 mois en 2007. Nous avons analysé les coupes congelées et les spécimens fixés pour tous les cas potentiellement discordants à l'aide d'un microscope multitête, dans la recherche d'un consensus quant au type d'erreur et à la raison de celle-ci. Nous avons passé en revue les dossiers cliniques pour mesurer, le cas échéant, un quelconque impact négatif sur la prise en charge clinique immédiate. RÉSULTANTS: Les coupes congelées ont le plus souvent été demandées pour des spécimens de tissu de la tête et du cou, du système nerveux et des voies génitales féminines. Vingt-huit coupes congelées (3 %) ont été écartées. Nous avons relevé 24 diagnostics discordants concernant 3 % des cas et 2 % des spécimens. Les systèmes et organes pour lesquels la fréquence de la discordance a été la plus élevée par rapport au nombre total de spécimens du même type, ont été le système nerveux, la tête et le cou et les poumons. Parmi les erreurs relevées, la plupart ont été attribuables à une mauvaise interprétation diagnostique, suivie de problèmes relatifs au prélèvement tissulaire. Dans 14 cas, l'erreur a pu exercer un impact négatif sur la prise en charge clinique immédiate. CONCLUSIONS: Nos résultats viennent étayer les données canadiennes sur la corrélation entre les coupes congelées et les lames adhérentes; nous notons que nos taux de concordance sont comparables à ceux qui sont cités dans la littérature.

Secretory breast carcinoma: unique, triple-negative carcinoma with a favorable prognosis and characteristic molecular expression.

Secretory carcinoma is a rare but distinct subtype of breast carcinoma, with characteristic histomorphology and generally favorable prognosis. Although it was originally described as a juvenile breast carcinoma, occurring in young children, most cases have been reported in adults of both sexes. As the name implies, the characteristic histomorphology is the presence of a large amount of intracellular and extracellular, eosinophilic secretion material that stains positive for periodic acid-Schiff. Most tumors stain positive for S100 and negative for estrogen receptor, progesterone receptor, and ERBB2 (formerly HER2/neu) (ie, triple negative). In addition, some secretory carcinomas demonstrate a basal-like immunoprofile. Recent studies have shown the characteristic molecular feature: a balanced translocation t(12;15), resulting in an ETS variant 6-neurotrophic tyrosine kinase receptor type 3 (ETV6-NTRK3) fusion gene encoding a chimeric tyrosine kinase. Although rare events of axillary lymph node or distant metastases have been documented, the prognosis is generally excellent. The methods of surgical treatment and the role of adjuvant therapy, particularly for young patients, remain controversial.

Basaloid squamous cell carcinoma: two case reports.

Basaloid squamous cell carcinoma (BSCC) is a rare and aggressive variant of squamous cell carcinoma (SCC) that occurs preferentially in the upper aerodigestive tract. We present two cases of BSCC, one arising in the conjunctiva and the other arising in a paranasal sinus. Clinical and pathological findings in these two cases, including immunohistochemistry is presented along with brief discussion of literature. To the best of our knowledge, this is the first report of BSCC of the conjunctiva. BSCC of the head and neck should be distinguished from adenoid cystic carcinoma, small cell neuroendocrine carcinoma, basal cell adenocarcinoma, adenosquamous carcinoma, squamous cell carcinoma, spindle cell squamous carcinoma, mucoepidermoid carcinoma, and adenoid cystic carcinoma.