Massachusetts Surgical Journals can be found everywhere in the wasteland of the Commonwealth in Fallout 4 and there are 9 different editions of the magazine. With the magazines you become the deadly surgeon and caused more durable body tissue damage at your enemies.
Each collected issue gives you permanently + 2% body part damage and with a total of 9 issues you get a damage bonus of + 18%. Below you see the locations of all issues:
Greenetech Genetics - Go to the laboratory of Greenetech Genetics in the northeast of Diamond City. You will find the issue on the first floor on a table surrounded by red sofas.
Medford Memorial Hospital - Go to the Medford Memorial Hospital in the northeast near Vault 75. Immediately after entering you will find this issue on the first floor in the office left.
Cambridge Polymer Labs - Go to the Cambridge Polymer Labs just south of Lexington, and the police station of Cambridge. Take the stairs on the right to the first floor and in the office of the CEO. There you will find the issue on the desktop.
Greater Mass Blood Clinic - The Greater Mass Blood Clinic can be found in the West, just south of Fort Hagen. Go to the first floor of the ruined building, there you have to hack a terminal to access to the room with the issue.
Sandy Coves Sanitarium - Immediately after entering the Sandy Coves Sanatorium in the northeast, near the Museum of Witchcraft, you must hack the computer terminal at the reception, which grants you access to a nearby room with the magazine.
Boston Public Library - This issue requires a lot of effort. You need overdue books that can be found in the Boston Public Library, but also in many other places in the wasteland. For each overdue book you get 5 marks, which you can redeem for prizes on the same terminal - at the book return terminal. One of them is this issue for 50 brands. So you need 10 books to get this issue. Use the side entrance of the Boston Public Library in the city center, to go directly to book return terminal.
House of Cabot - The house is located north of the Cabot Goodneighbor and can only be accessed if you start the associated side quest series. This begins when you are approached by an NPC in one of the larger settlements or the Raider done at the Parsons State Insane Asylum in the Northeast. Go to the second floor in the house where you can find the magazine on the desk in one of the bedrooms.
Parsons State Insane Asylum - The same quest that already brings you into the Cabot house, in the last quest you battle with Jack Cabbot into the lower regions of the mental hospital - Parsons State Lunatic Asylum. There you will find this issue
Med-Tek Research - To enter the lower floors of Med-Tek Research, you have to increase the relationship with the companion MacCready, so that he gives you a series of quests. The last quest leads you in this area. Just follow the quest marker to the end. On the same table on which you will find the cure, there is also this issue.