Algunos conceptos básicos de la teoría de colas aplicables en la planificación de un servicio de anatomía patológica / Some basics concepts of queueing theory applicable in the planning of a pathology department

Introducción: Nos planteamos el problema: ¿cuál es el número adecuado de facultativos en un servicio de anatomía patológica (SAP) para responder sin demora al número de solicitudes de estudio que se reciben? Material y métodos: Aplicamos conceptos básicos de teoría de colas y motivamos al lector a introducirse en ellos. Resultados y discusión: Un SAP funciona como un sistema de colas y se ajusta a los modelos de cola infinita con uno (M/M/1) y, todavía mejor, con múltiples recursos (M/M/m). El número de facultativos (m) ha de cumplir: m » velocidad de llegada de biopsias al SAP/velocidad de cierre de biopsias por facultativo Conclusiones: Como sistema de colas, un SAP solo es viable si su capacidad de respuesta es mayor que las necesidades planteadas por la demanda. El modelo de múltiples recursos (facultativos) amortigua mejor los aumentos sostenidos de la demanda (AU)

Introduction: The problem of the optimal number of pathologists required to provide a rapid response to the volume of studies requested is considered. Material and methods: The basic concepts of the queueing theory are applied and recommendations for their use are made. Results and discussion: Pathology departments (PD) work as a queuing system and adapt to infinite queue models with a (M/M1) or, preferably, multiple servers (M/M/m). The number of pathologists (m) must achieve: m » velocity of arrival of biopsies to the PD/velocity of completion of biopsy reports by pathologists. Conclusions: Like a queueing system, a PD is viable only if its capacity of response is greater than the demand. The model of multiple resources (pathologists) better absorbs a sustained growth in demand (AU)

Ileal Vanek's tumor mimicking cecal carcinoma.

Inflammatory fibroid polyps or Vanek's tumors are rare benign pseudotumoral lesions with morphological characteristics similar to those of submucosal mesenchymal tumors. They have been described in the gastrointestinal tract, most frequently in the gastric antrum. We present a case of ileal Vanek's tumor associated with a raised carcinoembryonic antigen level and with radiological and endoscopic features mimicking cecal carcinoma.

Hepatoid adenocarcinoma of the stomach - a different histology for not so different gastric adenocarcinoma: a case report.

Hepatoid adenocarcinoma is an extrahepatic tumor characterized by morphological similarities to hepatocellular carcinoma. Hepatoid adenocarcinoma of the stomach is a cancer with an extremely poor prognosis with few cases reported. Here, we describe a 75-year-old Spanish man referred to our hospital with a history of abdominal pain, general fatigue, anorexia and sickness. Initial study revealed anemia, and computed tomography scan and abdominal ultrasonography showed multiple metastases to the liver with hepatocellular carcinoma characteristics in a liver with no cirrhotic change. Further study included a serum level of alpha-fetoprotein (AFP), which resulted markedly elevated, and a conclusive esophagogastroduodenoscopy describing an elevated tumour growing through the cardia and gastroesophageal junction with foci of necrosis and haemorrhage. Gastric biopsies of the tumor revealed poorly differenciated adenocarcinoma, with hepatoid differentiation. After a diagnosis of AFP-producing hepatoid adenocarcinoma of the stomach with multiple liver metastases was made, pallitive total gastrectomy, without liver resection, was performed. Patient recovered well after surgery, and entered into a palliative systemich chemotherapy protocol. Although this illness is recognized as having poor prognosis, the patient remains alive 8 months after the operation. Accurate diagnosis of hepatoid adenocarcinoma of the stomach is important, and should be suspected under certain circumstances. We describe this rare case of hepatoid adenocarcinoma of the stomach, and review the literature concerning the clinicopathological aspects.

Early distant relapse after optimal local control in locally advanced rectal cancer.

We present a case of locally advanced rectal cancer with initial optimal local control after neoadjuvant concurrent chemoradiotherapy followed by surgery; early liver recurrence then occurred and was treated again with curative intent with neoadjuvant combination chemotherapy followed by liver surgery. We reflect on this difficult problem and discuss relevant topics to this case report.