Workload Measurement in Subspecialty Placental Pathology in Canada.

BACKGROUND: Workload measurement is important to help determine optimal staffing and workload distribution for pathology laboratories. The Level 4 Equivalent (L4E) System is the most widely used Anatomical Pathology (AP) workload measurement tool in Canada. However, it was initially not developed with subspecialties in mind. METHODS: In 2016, a Pan-Canadian Pediatric-Perinatal Pathology Workload Committee (PCPPPWC) was organized to adapt the L4E System to assess Pediatric-Perinatal Pathology workload. Four working groups were formed. The Placental Pathology Working Group was tasked to develop a scheme for fair valuation of placental specimens signed out by subspecialists in the context of the L4E System. Previous experience, informal time and motion studies, a survey of Canadian Pediatric-Perinatal Pathologists, and interviews of Pathologists' Assistants (PA) informed the development of such scheme. RESULTS: A workload measurement scheme with average L4E workload values for examination and reporting of singleton and multiple gestation placentas was proposed. The proposal was approved by the Canadian Association of Pathologist - Association canadienne des pathologistes Workload and Human Resources Committee for adoption into the L4E System. CONCLUSION: The development of a workload measurement model for placental specimens provides an average and fair valuation of these specimen types, enabling its use for resource planning and workload distribution.

H3.1 K36M mutation in a congenital-onset soft tissue neoplasm.

We describe a patient who presented with a congenital soft tissue lesion initially diagnosed as infantile fibromatosis at 15 days of age. Unusually, the mass demonstrated malignant progression leading to death at 20 months of age. Biological progression to malignancy is not known to occur in fibromatosis, and fibrosarcoma is not known to progress from a benign lesion. Whole-exome sequencing of the tumor identified a driver mutation in histone H3.1 at lysine (K)36. Our findings support the link between oncohistones and infantile soft tissue tumors and provide additional evidence for the oncogenic effects of p.K36M in H3 variants.

Case report: necrotizing enterocolitis with a transverse colonic perforation in a 2-day old term neonate and literature review.

BACKGROUND: Necrotizing enterocolitis (NEC), while classically discussed in preterm and low birth weight neonates, also occurs in the term infant and accounts for 10% of all NEC cases. Despite there being fewer reported cases of NEC in term infants, these presentations demonstrate differences in the onset, severity and risk factors from the classic presentation observed in premature infants. We present a novel case of term NEC that contravenes the reported literature making departures from clinical presentation, risk factors and location of perforation in an otherwise healthy term two-day old infant born after an uncomplicated pregnancy who presented with hematochezia. CASE PRESENTATION: A healthy term baby born after an uneventful pregnancy presented with bloody stool at 2 days of life who was otherwise well. Investigations revealed pneumoperitoneum from a large proximal transverse colonic perforation secondary to NEC. No typical risk factors for NEC were found. CONCLUSION: Given the life-threatening potential of an unrecognized perforation we recommend the inclusion of NEC on the differential for neonatal hematochezia.

A forme-fruste variant of congenital midline cervical cleft with hamartomatous adnexal elements managed without Z-plasty.

Congenital midline cervical cleft is a relatively uncommon malformation of the anterior neck for which most of the current literature comprises case reports. There is a spectrum in clinical features, but the prototypical description is of a midline groove or cleft of atrophic skin with a skin tab at the cephalic end and an inferiorly oriented sinus tract at the caudal end. An underlying dense fibrous cord is usually described. The most widely postulated etiology is impaired midline fusion of the upper branchial arches. Some of the recent case reports advocate for removal of the defect and closure with Z-plasty. Here we report a case of a similar congenital lesion in a male patient. In our case, there was a conspicuous skin tab caudal to which there was a dense fibrous cord running vertically in the midline under the skin documented since the child was first examined at 5 months of age. The skin overlying the fibrous cord was mildly atrophic and only very subtly indented but was not desquamating or edematous. There was no open sinus tract at the caudal end, but within the skin tab, on histology, we did note an inclusion cyst lined by respiratory type mucosa with squamous metaplasia. The cord was composed of fibrous tissue and skeletal muscle, as has been described. In our case, we describe hamartomatous proliferations within the dermis of the skin tab, not previously described, which we feel provides further support to the embryologic closure defect hypothesis. Our case is distinct because the absence of an external cleft allowed for a more conservative surgical approach.

The use of rapid assessment of enteric ICC and neuronal morphology may improve patient management in pediatric surgery: a new clinical pathological protocol.

Alterations in interstitial cells of Cajal (ICC) distribution and density may seriously influence gut motility. We and others have documented a disturbance of ICC and neurons in Hirschsprung's disease (HD), intestinal ischemia, and inflammation. The ability to remove intestine with permanent dysmotility improves significantly the prognosis. This may be important in the developing intestine especially in HD. More complete pathological information increases the accuracy of surgical decisions. Therefore we sought to develop a rapid, intraoperative immunohistochemical protocol for ICC and neurons in surgical specimens for routine diagnostic and therapeutic assessment of pediatric patients. To date, cKit is the only reliable immunohistochemistry for ICC identification. There are multiple antibodies in use for neuronal identification. A comparison of fixation methods and immunostaining using cKit and multiple intestinal neuronal antibodies was done. Fresh segments of surgically resected intestine were sectioned and stained using antibodies for ICC cell identification (anti-cKit) and for neuronal characterization. By carefully changing tissue fixation methods, different neuronal antibodies were tested to determine an optimal rapid protocol. Each suggested protocol was tested on normal and pathological intestinal tissue and compared to the previous overnight immunostaining of the same tissue. A new rapid tissue fixation and immunostaining protocol using cKit for ICC identification and NF 68 was developed. By employing this protocol, we could obtain ICC and neuro-immunohistochemistry in unfixed frozen sections within 1 h with tissue vibration to diminish the time for immunostaining. Without vibration the protocol takes 3 h. ICC and enteric neuronal changes could be readily observed and the quality of staining was comparable to standard immunohistochemistry. Each gut pathology displayed characteristic changes in ICC and neuronal density/distribution in the affected bowel. The time-scale of the 1-h immunoprocessing is still longer than the standard clinical pathological "quick" sections using H&E staining; however, the protocol duration is within the surgery timescale. Standard H&E stain used in combination with our rapid neuronal and ICC immunohistochemistry protocol enables a fast, comprehensive, and accurate assessment of the pathophysiology of signaling networks controlling gut motility while the patient is still in the operating room. We propose that the addition of this simple and rapid immunohistochemical assessment in the pathologist evaluation of surgical specimens would result in a more complete characterization for diagnosis and prognosis of the pediatric patient. Specifically, we propose that this test will differentiate good versus poor prognosis HD patients based on their neuron/ICC ratio and present a rapid, standardized method for use in general pathology.

Unusual case of mesenteric venous thrombosis associated with oral contraceptive use in an adolescent girl.

A 16-year-old girl presented with hematochezia and abdominal pain. The patient developed a small bowel obstruction that required a laparotomy, which showed a segment of grossly infarcted small bowel with 3 perforations, localized abscesses, and creeping fat. Resection and an end-to-end anastomosis were performed. Pathologic examination showed underlying mesenteric venous thrombosis with no evidence of Crohn's disease. Hematology workup showed no evidence of a congenitally inherent hypercoagulable state. The use of oral contraceptives was the only predisposing factor identified.

Brain metastases in Wilms' tumor: case report and literature review.

A 2-year-old girl who had a stage 2, favorable-histology Wilms tumor diagnosed when she was age 10 months presented with multiple brain metastases at second recurrence. She had been treated with combined radiotherapy, surgery, and chemotherapy; at 2 months after treatment, recurrent disease developed in the central nervous system and she died. Brain metastases are rare in the natural history of Wilms tumor. Although it does not appear that cerebral metastases are a barrier to tumor eradication and long-term survival if treated with combined modality therapy, treatment should be individualized.