Initial unsolicited report received from the literature on 03-Aug-2017. This case is linked with 2017SA145424, 2017SA145425, 2017SA145426 (Same literature). Abstract: Macrophagic myofasciitis (MMF) is an inflammatory condition associated with the intramuscular (i.m.) injection of aluminum adjuvantcontaining vaccines. It is clinically characterized by myalgia, weakness, and chronic fatigue and histologically by aggregates of cohesive macrophages with abundant basophilic, periodic acid-Schiff (PAS)-positive, diastase-resistant granules that percolate through the peri- and endomysium without eliciting substantial myofiber damage. The definitive diagnosis of MMF requires demonstration of aluminum within these macrophages. We evaluated the Morin stain, a simple, 2-step histochemical stain for aluminum, as a confirmatory diagnostic tool for MMF. Among 2270 muscle biopsies processed at UTSW between 2010 and 2015, a total of 12 MMF cases and 1 subcutaneous vaccination granuloma case were identified (11 pediatric, 2 adults). With the Morin stain, all 13 cases showed strong granular reactivity within the cytoplasm of macrophages but not in myofibers or connective tissue. Three cases of inflammatory myopathy with abundant macrophages (IMAM), 8 cases of granulomatous inflammation and 23 other deltoid muscle biopsies used as controls were all negative. Morin stain could be used in both formalin-fixed paraffin-embedded and cryostat sections. Thus, Morin stain detects aluminum with high sensitivity and specificity in human muscle and soft tissue and may improve the diagnostic yield of MMF and vaccination granuloma. This case involves six months old female patient who was vaccinated with a dose of DIPHTHERIA, TETANUS AND ACELLULAR PERTUSSIS VACCINE (DIPHTHERIA-TETANUS-PERTUSSIS (DTAP)), HAEMOPHILUS TYPE B (HIB) VACCINE (HEMOPHILUS INFLUENZA TYPE B (HIB)), dose of HEPATITIS B VACCINE (HEPATITIS B (HEPB)) and dose of PNEUMOCOCCAL CONJUGATE VACCINE (PNEUMOCOCCAL CONJUGATE VACCINES (PCV)) (batch number, expiry date, route and site of administration were not reported) on an unspecified date. Patient had cytogenetic abnormalities including inversion of chromosome 1p. Concomitant medication was not reported. On an unspecified date following vaccination patients had hypotonia, developmental delay and macrophagic myofasciitis (MMF) (Aluminum-Containing Macrophages in Macrophagic Myofasciitis).Time between last aluminum-based vaccination and muscle biopsy was reported as six months. Patient had other comorbidities that led to the initial muscle biopsy performed at quadriceps. Morphologically, biopsies from MMF cases typically contained aggregates of basophilic, cohesive macrophages with abundant granular cytoplasm centered in the perimysial connective tissue. Morin stain results were positive. Corrective treatment was not reported. Outcome of events was not reported. Upon internal review the case was considered as serious because of important medical event: Macrophagic myofascitis. List of the documents held by sender: none; Sender's Comments: This literature case concerns a 6 month old patient with history of genetic defect of inversion 1p who experienced Macrophagic myofascitis, Hypotonia and developmental delay after vaccination with DIPHTHERIA, TETANUS, PERTUSSIS (ACELLULAR) AND HAEMOPHILUS TYPE B CONJUGATE VACCINE, HAEMOPHILUS TYPE B (HIB) VACCINE, HEPATITIS B VACCINE (OTH MFR) and PNEUMOCOCCAL CONJUGATE VACCINE (OTH MFR). Time to onset is too long to be compatible with the role of vaccine. Hypotonia and developmental delay could be due to genetic defect which might be not related to vaccine. Biopsy was taken from quadriceps and morin Stain Detects Aluminum Containing Macrophages in Macrophagic Myofasciitis. More details regarding patient's medical history, history of received aluminum compound, name of the vaccines administered and investigation reports are needed for further assessment. Based on the available information no conclusion can be drawn. Moreover 4 vaccines were administered before the onset of events, making it difficult to assess the role of each vaccine.