The spatial diffusion theory and its patterns (expansion, hierarchical, contagious, and relocation) explain how phenomena disseminate from the origin of diffusion. By investigating the spatial pattern of specialist physicians' offices in the city of Mashhad, the present study showed that, contrary to common patterns, a new pattern of spatial diffusion was formed by increasing the number of phenomena but not diffusing them at the origin. This was a descriptive-analytical study and the sample included all specialist physicians' offices in Mashhad (including 27 specialist physicians and 2425 offices). To this end, a geographic database of specialist physicians' offices was created according to their type of specialty and addresses. Then, the diffusion pattern and origin of the offices were identified using spatial analysis models such as density profiles, mean center, and standard distance. Then, it was examined how each office diffused according to the type of specialty using spatial autocorrelation models, network analysis, and location-allocation. Finally, the diffusion rate of each specialty was determined using scatter diagrams and correlation coefficient. The results indicated that the distribution of offices in the city of Mashhad follows a new pattern called "inverse spatial diffusion". It is characterized by high mobility of phenomena at the origin, a high correlation between the number of offices in each specialty and their absorption rates, and non-diffusion of offices at the origin. This was resulted in high daily inflows and outflows of people to this area, low diversity of land uses, and isolation of this area from other parts of the city.